Category: Science

The Leonids? Are They in Town Again?

trimmed_beard_stevecu(I was rummaging around on some thumb drives and found this from 2001.  The Alert Reader will point out that USB drives were not around then.  True.  This was in a folder called “Floppy_Recovery”.  I actually bought a 3 ½ inch floppy disk drive and copied a pile of floppies into this particular USB some years back.  I added some “file photos” that would never have fit on a floppy, anyway).                Homepage

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The Leonids are neither a sixties group, nor a box of stronger breath mints, nor followers of a religion devoted to a deity named Leon ,  as you may have thought by the name but rather an event that takes place once a year around November 18th, when meteors rain down from the general direction of a point in the sky near the constellation Leo.  Well, perhaps “rain” is a misleading choice of words since the normal Leonid meteor “shower” consists of one meteor every few minutes and I personally have sat out in the November damp chill and not seen a meteor for fifteen or twenty minutes at a time.  Only the most demented Astronomy Nerds (A.N.’s) would put up with the amount of inconvenience involved to see what, for the non-Astronomy Nerd is less interesting than counting the number of cars with one headlight at four in the morning on a dark stretch of country road.

It is especially taxing for the urban A.N. because it involves a trip out of town of at least an hour to an isolated dark spot.  You might think that there are plenty of dark spots out there, but I dare you to find one!  About anywhere you can drive to in an hour around here (here is Houston) is lit either by passing cars or billboard lights or gleaming florescent signs.  In Texas, more than a few of the people who like to hang out in the country also like to mount a half dozen searchlights on their vehicles.   The one hope is to find a State Park and even then the non-Astronomy Nerds will wander around all night with flashlights that could illuminate the Grand Canyon.   They mean no harm, you understand, but these folks have never heard of the concept of night vision and routinely put their beam of light directly on your face as a sort of a greeting. and say “Hi! Whacha’ doin’?”

There is one exception, a state park that actually has made an effort to keep illumination off the sky and provided areas down twisting footpaths away from the roads where one can find uninterrupted darkness.  It’s Brazos Bend State Park and there is a nice dark place get a wide angle view of the sky or to set up telescopes. If you go there, please keep the flashlight use to a minimum and never illuminate anyone’s face. I didn’t manage to reserve a campsite early enough because all the other Astronomy Nerds thought four months ahead as opposed to my three.   I did find a spot in Stephen F. Austin State Historical Park.  It’s located near San Felipe which was the capital of newly declared independent Texas before it was burned to prevent it from falling to the advancing Mexican Army, who wanted Texas to be dependent again.  There are some reconstructed buildings (one’s a museum), statues and historical markers near the park entrance.  (Trivia question:  What does the F. in Stephen F. Austin stand for?)

StephenFAustin

LogCabin

Those unfamiliar with astronomical events always assume that you will be looking at a meteor shower with a telescope.  As an exercise to prove how silly that is, extend your arm at the sky with your thumb up.  That tiny piece of sky covered by your thumb is many times the field of view of an average telescope.   You could see more of the sky by looking through a two-foot-long pipe than through a telescope!  Meteors happen all over the sky, during a shower or otherwise.  Why on earth would you limit your view to a tiny patch of sky?

It is obvious that hardly anyone bothers to look at the sky anymore.  I’ve had people swear to me that they’ve seen the space station hovering overhead (turned out to be Jupiter).   Others expect to see Venus always near the moon.  A few are not even aware that the moon can be seen in the daytime. But, shoot, is there any real reason for your average person to look at the sky these days?  Especially urban dwellers for whom the night sky is a brown haze, illuminated from below, at the best of times?

Austin_Statue2
Stephen F. Austin

I go out to see these things because I find it fascinating but I am aware that some do not share my enthusiasm.  Nevertheless, I dragged my wife and children along on this last expedition.  When I make the journey with other A.N.’s   we throw lawn chairs in the trunk and leave at midnight.  Provisions such as beef jerky and Shiner Bock beer (with appropriate designated driver, of course) are to be found in fueling depots along the way.  Stay up most of the night, doze off in the chairs and drive back with stiff necks in the morning.  This will not do for a family outing, however.  Especially with small children…who will only stay awake at night when you desperately want them to sleep.

It becomes a regular camping trip, then, complete with tent, sleeping bags, flashlights, blankets, pillow, portable propane stove and an ice chest with the entire contents of the kitchen refrigerator (as opposed to the garage refrigerator).  Might as well take along the telescope (for looking at planets and stars, not meteors, you understand) and the bicycles because we’ll have some daylight hours to kill.  Appropriate stuffed animals and annoying hand held electronic games to keep the offspring occupied.   The target for leaving had been ten o’clock.  It was eleven thirty when we left.

SFA_Park              The first thing we found out at the campsite is that we have forgotten what to do on camp-outs.  We rode bicycles, walked around for a while and played twenty questions.  It was still only four o’clock in the afternoon and we were sitting around looking at each other. So we did what any bored campers would do, we went into town.  Not really into town, but that peninsula of fast-food and big-box retail that grew up around the interstate.  There we bought charcoal, which we’d forgotten.  I’m not sure how we were planning to cook the hotdogs for dinner unless we boiled them on the propane stove…in a pot, which we also forgot.  And while it might be possible to roast marshmallows over a propane flame, I doubt it would be much fun.  Of course, any cooking would require matches, which we had also forgotten.

“So,” you are perhaps thinking, “Just when is he going to get to the part about the meteor shower?”

Meteor showers are best after midnight ’cause that’s when the Earth (the part of Earth where it’s after midnight, that is) is plowing “head-on” into this cloud of dust that makes meteors.  The cloud itself has been spewed out along the orbit of a comet that crosses the Earth’s orbit.  Now, I know what you’re thinking.  It’s the same question reporters ask astronomers (in an urgent voice) every time the subject of comets and or near Earth asteroids comes up.

You’re thinking “Crosses the Earth’s orbit!  But what if it hit the Earth?”

Relax, you are far more likely to be struck by lightning, hit by a bus and bitten by a shark, all simultaneously.  The orbits don’t actually cross but just come close enough to where the Earth will run into that scattered dust cloud.  And, even if they did cross exactly, then a collision would require that they both arrive at the same point in their orbits at the same time, which almost never happens neither.

So, there are times when there is a particularly thick cloud of dust that we happen upon.   Not really thick, but just relatively thick, it’s still a dead ringer for absolute emptiness.   That’s what’s called a meteor storm.  Or the shower is said “to storm”.

Like this:  “I understand that some predictions say the Leonids are going to storm this year”

This is a particularly cool thing to say around Astronomy Nerds because somebody is always predicting a “storm” and so you would sound like you actually know what you’re talking about.  Of course you would be saying this to impress a bunch of people who hang out in the dark all night, staring up at the sky, so I’m not sure how useful this advice is.

The Leonids were supposed to storm last year, too – and the year before.  I made the trip back then with the largest of my two sons and we saw a few good meteors.  I always thought it would be cool if I could call them “My Three Sons” like the early sixties sitcom but I only have the two.  I suppose I could say “three” if I count the cat who is indeed a male albeit a “repaired” one. (Fixed?  Heck, I didn’t even know he was broken!) .

Yes, I know, you’d like to hear about the meteor shower.  Well, I arose after a fitful few hours of sleep to look at the sky and was extremely disappointed to see a complete cloud cover. I wasn’t surprised because this sort of thing happens all the time with meteor showers ’round here.  I sat down in my lawn chair to be miserable about it for a while.

While we are sitting here being miserable, let us discuss the difference between meteors, meteorites and meteoroids.  Way out in space is the particle of dust or bit of rock or chunk of stone that is cruising along, unaware that it is about to run into a planet.  That is a meteoroid.  Anything that ends with “oid” is out in space and usually relatively small.  I say relatively because a “planetoid” or “asteroid” can be the size of, say, North Dakota and still be small when compared to a planet or an asteroid like Ceres, which is bigger than Texas.  When this unsuspecting meteoroid actually passes through the atmosphere it makes a streak of light that can be seen by all the Astronomy Nerds and anyone else foolish enough to be out in the cold, damp night, assuming its not completely clouded over like now.  That is a meteor.  Most of these streak-makers – the vast majority – burn up completely, but a meteorite is a chunk of rock that you can pick up off the ground that once was a meteoroid and made a meteoric flash of light before its arrival.

Three
Meteorite                                                   Meteoroid                                      Meteor

I used to say wait till it cools off before you pick it up, but a meteorite, (I find out) by the time it hits the ground, has slowed to mere “falling rock” speed and has cooled off considerably.  I suppose it might still be warm, but it won’t be red hot.  Small comfort to anyone who happens to be in its path.  Relax!  As far as I know, there is only one documented case of a meteorite hitting a person.  Those who minds retain such useless information (yo!) remember seeing a black and white picture of a huge ugly bruise on the unfortunate lady’s abdomen.  She recovered.  These days meteors bring in big bucks from collectors so it might be worth the pain if it did happen.  But it’s actually far more likely that you’ll win the state lottery so hope for that instead.

I sat there for a while thinking what a bummer it was that I had planned this for months and here I was going to miss the whole thing.  I could have driven out to West Texas, maybe, where the climate tends to be drier.  I noticed a small hole in the clouds with a few stars visible and decided that maybe a few meteors would pass across it.  This is what is metaphorically called “grasping at straws”.

Over the next hour, to my great astonishment, the sky cleared off completely.  I saw a meteor, then another, then more.  It was about two A.M. with a peak expected around four.  I’d seen enough to wake up the family.  You have to be careful about waking up your family at two A.M. It is absolutely essential that you have something impressive to show them or the next time you try this silliness you’ll be out there alone.   Nobody was disappointed.   This was a major meteor storm to be sure.  At first I’d counted for a minute and found about six firm meteors.  That is to say, I’m sure they weren’t fireflies. That’s an hourly count of 360 – impressive enough.   I don’t want you to think that I did this in any scientific way.  In fact, I didn’t have my watch on.  I counted, one-thousand-one, one-thousand-two.    And since I can’t walk and chew gum, I kept a tally of meteors on my fingers.  I belong to that group that prefers the one-thousand-one method to the more popular one-mississippi method.

Storm

Around three or three thirty or so (I didn’t have my watch, remember?) I counted 12 in a minute.  Then, sometime after four there were 22 in a minute.  I had my shoes off, you see, to count toes and used eyelids and was lucky that there weren’t more than 22, or I’d never have seen ’em.

(Since then, I have learned a new method of finger-counting, which I described in “On Zeno’s Swim Team”.  It’s good up to 99. )

I didn’t have a clear view of the whole sky by any means and there was a bit of haze, but it was still an experience of a lifetime.  A published “official” count in the newspaper the next day was 1250 for the peak.  These are from people who count for an entire hour with stopwatches and click-counters.  My 22 in a minute calculates out to 1320 per hour.  Not bad for fingers and toes and “one-thousand-one”!

I kind of hated to call my friend who is a fellow Astronomy Nerd who was unable to make the trip and tell him what he missed.  I already have a cousin who’s mad at me since I described the experience.  She knew about the shower but didn’t go see it because I didn’t call up and tell her how good it would be.  Truth is, I didn’t know how good it would be either.

Trivia answer:  Stephen Fuller Austin

Hasta Luego,

Steve

Cartoon Physics Required for the Green New Deal

SteveTrucker2 Ten years?  Balderdash – three centuries would not be enough!

By Steve Campbell    February 24, 2019

The details of the term “Green New Deal” change every time the proponents of the GND are pinned down on the definition.

However, the New York Times said this much on February 2, 2019:

“It includes a 10-year commitment to convert “100 percent of the power demand in the United States” to “clean, renewable and zero-emission energy sources, to upgrade “all existing buildings” to meet energy efficiency requirements and to expand high-speed rail so broadly that most air travel would be rendered obsolete.”

The fact that anyone could list these three concepts as actual goals speaks volumes about how little is understood about energy use in the US.

Allow me to explain.

Please note that in the paragraphs to come, energy industries are referred to by capitalized names (Wind, Solar, Coal, etc).

 Energy Consumption in the United States

Lawrence Livermore National Laboratories – among many other activities — does an energy audit of the United States every year.  In 2017 (the latest complete year available), the United States used 97.7 Quadrillion British Thermal Units – mercifully referred to simply as “Quads”.  Please see the 2017 flow chart below.

Energy_US_2017.png

Figure 1:  LLNL flow chart for US energy use in 2017

One Quad is equal to about 170 million barrels of oil.  But, do not be distracted by the units.  The important concept here is what sources provide what fractions of the total energy budget.  Luckily, the amount of energy in quads is almost the same number as the percentage.  That information has been collected by your humble narrator and is displayed as a table and pie chart, below.

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Figure 2:  Comparison of energy sources by percentage.  Table and graph by author.

The earlier energy flow charts from LLNL show that “Renewable” sources in the mix have quickly increased by the equivalent of 48 million barrels of oil per year (0.285 Quads) in the last 5 years, thanks largely to generous subsidies, that caused Warren Buffet to observe that:  (Quoting “The True Cost of Wind Electricity”)

“….we get a tax credit if we build a lot of wind farms. That’s the only reason to build them. They don’t make sense without the tax credit. ”

Doing the Math

This “Green New Deal” only needs multiply Renewable capacity by a factor of nine to replace Oil, Natural Gas, Coal  and Nuclear.  At the current — heavily subsidized — rate of increase, one might think that only 311 years (88.7 quads to be replaced, divided by 0.285 quads/year growth rate) would be required.

That simple-minded, optimistic estimate would be the case only if green power plants last forever – they don’t.  Wind and Solar plants are lucky to last 30 years.  Strike out that 311 years and change the date of completion to “never”.

Another problem is that Wind and Solar are intermittent and require 100% backup – by real energy like Natural Gas or Coal.  So, Wind and Solar won’t actually “replace” anything.  The dirty little secret is that they never have done so.

And as far as Biomass is concerned, it should be mentioned that right now the corn used to make ethanol (in the U.S. alone) could otherwise feed about One Billion People. Do we really want to multiply that number by nine as well?

Hydroelectric dams could actually contribute significant additional energy.  But those are no longer considered “Green” and Environmentalists are advocating for their removal. Hydro has decreased in the last 5 years.

Geothermal — with a great deal of expense — could realistically be increased by a factor of 9.  At that level, it would not even replace the disappearing Hydroelectric industry.

The idea of replacing airplanes with trains has good news and bad news.  The good news is that trains really are electrically driven.  The bad news is that their electricity comes from burning diesel fuel in locomotives or (only in big cities) from overhead powerlines, which also need a source of energy.  Stringing powerlines almost everywhere on the national railroad grid cannot be done in ten years, either.  Like-wise not appearing out of thin air is the enormous amount of additional electricity required to replace the diesel fuel.

Conclusions

The idea that this could be done in ten years is completely, utterly, stupidly absurd – to say nothing of the hideous expense.  Yet, people are actually supporting this idiocy with straight faces.

This whole “Green New Deal” relies on “Cartoon Physics”.  You know the drill — where Wylie Cayote saws off the tree branch, which stays in place (supporting the Roadrunner) as the tree trunk and Wylie drop away.   Or, he hangs in the air until he looks down to see that he has run off the cliff.  Then he survives the thousand-foot fall and returns to the cave to hatch a new plan.

Life is not a cartoon.  Three centuries of crippling expense, poverty-inducing regulations and forced re-industrialization would not be nearly enough to complete the “Green New Deal”.  Even if it were possible, it would have no effect on the alleged Climate Change, whatsoever.  Not least because no other nation on Earth would be so irresponsible to its own citizens as to join this complete idiocy.

The Green New Deal is simply a method to multiply taxes and introduce an all-powerful dictatorship of regulations that will make Nicolas Maduro look like a Libertarian.

Read More:

Whence Electricity         An Ill Wind     One Climate Fact

Scenic Views in the Solar System

trimmed_beard_stevecu    Homepage     Portfolio

This was posted before, over at the old WordPress site.  I have since updated the pictures with the latest images of Pluto and Charon.  Also, comparison to the view of the moon from Earth is included in each picture and a lot of reference lines were deleted.  January 25, 2019

Steve Campbell     December 2015

Introduction

The full moon, especially when it is near the horizon has always been a most impressive sight and there are few that compare…at least on Earth. The truth is that your index finger at arm’s length can cover the moon. You will need to close one eye for this trick, though. If you saw Tom Hanks in Apollo13, you know the drill. The full moon covers less than one half of one degree of arc. By the way, the idea that the moon is somehow magnified by being near the horizon is just an illusion.  If you measured the angle it “subtends”, you will come up with the same number when it is overhead or low in the sky. Call it a Jedi mind trick, if you like. Figure A is a simulation of the Moon, as seen from the Earth. So that we can make a fair comparison, the field of view here is 10 degrees across. I will keep that constant as we move around. The lines are just the plotted orbits of the moon and other planets in the background.

moonfromearthsolo

Figure A: A simulation of the Moon as seen from Earth. The field of view is 10 degrees wide. That scale will be continued in the following images – until it doesn’t work.  I’ll include the moon in those images as a reference.

In the neighborhood

Impressive as our full moon view may be there are other, more breath-taking vistas to be had, with a small matter of transportation to be solved. There is one that has actually been experienced by Apollo astronauts on eight missions – each with a crew of three – that reached the moon. So, that is exactly 24 people, right? Wrong, twenty one. John Young and Eugene Cernan both went to the moon twice and landed once. Jim Lovell went twice and alas, did not land either time. But all these guys saw the Earth from the moon, even if only 12 saw it from the surface. That sight is even more striking. Figure B is a simulation of the Earth as seen from the moon.

earth_from_moon_comp

Figure B: Simulation of the Earth as seen from the moon. Same scale

As awe-inspiring as this view may be, you can still hide this behind a single digit, but you will need to use your thumb. The Earth’s atmosphere is not depicted here. That would make it more interesting, especially during a lunar eclipse. At that time, the Earth would be illuminated only by artificial lights and the occasional burst of lightening. If it were a total lunar eclipse, the rim of Earth’s atmosphere would be aglow with the red hues of every sunset and every sunrise in the world. The lunar landscape would be bathed in a soft red glow. Not bad, eh?

The Outer Limits

Until recently it was assumed that the Earth-moon system was the closest to a double planet, but that ended in 1978 when Pluto’s moon Charon was discovered. Compared to the Earth/Moon system, Pluto and Charon are much closer to the same size and much closer together. So, you would think –and be correct – that Charon would appear much larger from Pluto than the Moon from Earth. Figure C is a simulation (same scale) of Charon as seen from Pluto.

charon_from_pluto

Figure C: Charon as seen from Pluto. Note that this is an actual image of Charon, from the New Horizon’s flyby.

As you can see clearly, Charon is a much more imposing figure than the Earth from our moon. To continue our arm’s-length-finger imagery: I am quoting a New Horizons researcher whose name escapes me when I say “It would take three fat fingers to cover up Charon.”

However, I would point out a few drawbacks to this one. First, the lack of color (as compared to Earth, at least) should subtract a few points. Second, Charon will not be seen as “full” except for twice in a Pluto year, when the plane of the Pluto/Charon orbit is aligned with the Sun/Pluto orbit. A Pluto year is about 248 Earth years. Third, the Sun is very dim out there by Pluto and the whole scene will be very obscure. Fourth, Charon is tidally locked, always turning the same face toward Pluto and Pluto does likewise to Charon. This means that Charon always appears in the same spot in the sky, unless you are in the other hemisphere, then you never see it anyway. And, finally that eclipse scenario we talked about with the Moon and Earth only happens around those times of “full Charon” (every ~124 years) and it has no atmosphere to make it more interesting.  The alert reader (that guy, again) will point out that Pluto must be much larger as seen from Charon than the other way around. Correct. Figure D is just that scenarion.

pluto_from_charon_comp

Figure D: A simulation of Pluto as seen from Charon. Again, the surface features are guesswork and not updated by the recent New Horizon probe’s imagery.  

You see that, in our 10 degree wide view, Pluto has filled it, at least vertically. Clearly, this is the most stunning view, yet. One full hand, at arm’s length might not even cover this up. As I note in the caption, this is not the real image of Pluto, which, as it turns out is much more interesting. However, most of the objections of the view of Charon apply here. It is very dark. Pluto will always be in the same spot in the sky, if it is in the sky, at all. Pluto will only be “full” once in 224 years and the eclipses will be about that rare as well. There will be a “rim of light” during a full eclipse, but it will be pale blue.

Now is where the real estate people would put the “hook” that draws you in to the thing they are really selling. As it turns out, there are much more amazing views available, much closer to home, far more dynamic, interesting and much better illuminated than those “outer limits” properties that you have been seeing!   Let’s talk about the Jupiter neighborhood.

There is this moon called Io (pronounce by purists with a short “I” and by everybody else, with a long “I”). It is the closest of the four main “Galilean” satellites of Jupiter. Io is a small moon of Jupiter that is still 37% larger than Earth’s moon.

It has a view of Jupiter that is un-paralleled by any other self-respecting Jovian moon (i.e., with a significant surface gravity). I have summoned up another simulation at our same scale of 10 degrees across., in Figure E.

jupiterfromio_10comp

Figure E: Simulation of Jupiter seen from Io. Clearly a change of scale is in order!

This is an order of magnitude greater than what we have looked at previously. We need to back off of this 10 degree wide view. Figure F is a view with 45 degrees as the width of field. To show how much we have “zoomed out” please see the inset at lower left that shows the moon as seen from Earth at the same scale.

jupiterfromio_25comp

Figure F: Jupiter (in a section of sky that is 25 degrees across) as seen from its closest large moon, Io.   Note the comparable view of the Earth’s moon – from Earth.

This is clearly the most spectacular view we have yet imagined. The arm’s-length comparison:  Tom Hanks would have to hold up a pizza pan that is 13* inches across to cover this sight. And here, we will have a view of Jupiter that goes from “full” as you see it here, through a half-phase to a crescent, to “new” and back in less than two days.  Add to that the fact that Jupiter rotates in about nine hours and the clouds are in constant motion and changing. And also, the colors (in comparison to our own moon) are vivid and diverse. When Io is eclipsed, passing behind Jupiter, there will also be lightening and auroras that should surpass anything seen on Earth from orbit.

*Ironic, that!  😉

Conclusion

I think that when it comes to spectacular scenic outlooks in the Solar System, we have found the ideal spot – Io. Remember to move to the side facing Jupiter and the view is always available.  But, before you decide you would like to live there, I should say that I failed to mention that it is a very active place, geologically speaking – far more so than Earth. Io is prone to sudden outbreaks of hot molten Sulfur volcanoes. It also orbits in a radiation belt around Jupiter. And to quote astrobio.net (7): “The radiation in Jupiter’s belts is a million times more intense than in Earth’s belts.”.

So, you see that there is this great view at Io, but there are a few details that complicate things.

Hasta Luego,

Steve

 References

  1. Solar System Simulations:   http://space.jpl.nasa.gov/
  2. Apollo Astronauts:  https://en.wikipedia.org/wiki/List_of_Apollo_astronauts#Apollo_astronauts_who_walked_on_the_Moon
  3. Charon: https://en.wikipedia.org/wiki/Charon_(moon)
  4. Planetary Statistics:  http://www.windows2universe.org/our_solar_system/planets_table.htm
  5. Moon comparisons: https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size
  6. More on Jovian moons:  https://en.wikipedia.org/wiki/Moons_of_Jupiter
  7. Jupiter Radiation Belts: http://www.astrobio.net/news-exclusive/hiding-from-jupiters-radiation/

Neptune – The Farthest Giant

 

 

Steve Campbell      March 2016

I managed to destroy this post unintentionally.  I fixed it and threw in a new Triton movie YouTube link. “Sail past Triton  “

Introduction

Neptune was the first planet to be discovered by mathematical means.  After the discovery of Uranus and subsequent observations of the Seventh Planet, it was observed that its orbit was not meeting expectations of Kepler’s Laws.  It was determined that there must be another planet -farther away – that was influencing the orbit.  That planet was later discovered and quickly thereafter found to have a large satellite. (1)

Neptune is the farthest Giant Planet from the Sun and not surprisingly the last to be visited by a spacecraft.  In the old days, when your author was young, they called Jupiter, Saturn, Uranus and Neptune “Gas Giants”.  Now they reserve that title only for Jupiter and Saturn and call Uranus and Neptune “Ice Giants”.  As you may know the now call Pluto and Eris “Dwarf” Planets (I can’t agree with that).  As of today, Mercury, Venus, Earth and Mars are still “Terrestrial Planets”.  But soon, it seems to me, each planetary body will have its own unique category.

Quoting from my two-part series:

“One thing that might puzzle the average student might be why we had images of all the Outer planets by the 1970s and 80s and nothing but a dot or smudge for Pluto.  That all relates to what was called at the time “The Grand Tour”.  As it happened, there was an alignment of the outer planets in the 70’s and 80’s such that it would be possible to use gravity assisted orbital adjustments (“the slingshot effect”) to make it possible for a space probe to visit Jupiter, Saturn, Uranus and Neptune in one long and carefully managed trajectory.”

Again from Sneaking Up on Pluto:

“The Voyager probes (one of which actually made the complete “Grand Tour”) each had a main antenna that was capable of constant communications with the Earth.  This necessitated what is called a “scan platform” that held the instruments that need precise pointing, that moved independently of the antenna.  That configuration had proven troublesome on one of the Voyager probes at Saturn and data were lost.  That is because data storage was actually on a ½ inch, 8 track magnetic tape with a total capacity of about ½ Megabyte and a top baud rate of 56 kilobits per second (2).  That’s what I said – “Stone Knives and Bear Skins!” – so, real-time transmission was required for image data.”  Voyager was – despite my demeaning reference – quite advanced at the time and some of its imagery is still quite impressive.

 The image below depicts the identical Voyager 1 and Voyager 2 Spacecraft. (4) The dish antenna is 3.7 meters in diameter (12 feet, 2 inches) across.  The arm extending to the right contains the main experiments and the imaging “scan platform”.  The left arm holds the three radioisotope thermoelectric generators that power the probe.  The gold disk on the “body” is the famous CD with messages and images of Earth for anyone “out there”.  This CD was a pet project of Carl Sagan.  Carl has been inserted into the picture at the proper size to give it a sense of scale. 

This photo is from his brief and little-known “Fonzarelli” period.  Raise your thumbs, Carl!

voyager_nasawebcarlFigure A: The Voyager Spacecraft        NASA/NASA website

Neptune

About time we got around to the planet, I hear you thinking.  I have a table of planetary statistics (3) that serves as a good introduction for any planet.  You may expect to see this table in future posts.  Please see Figure B, below.

Figure B: Table of Planetary Statistics        NASA

You will notice that Neptune has 17 times the mass of the Earth and about 3.9 times the diameter.  That only works out that way because the mean density of Neptune is 30% that of Earth.  If it were as dense as the Earth, Neptune (of the same diameter) would have 60 times the Earth’s mass.   All four Giant Planets are low-density like that, but Neptune is the densest of them.  Likewise, all Giant Planets are fast spinning and Neptune is slower than most, rotating in 16 hours.  The Navy has adopted a 16 hour rotation of duties and sleep aboard out nuclear subs, so submariners would be right at home on Neptune.  Just a small tangent, I’ll get back on track, now.

Figure C: Neptune as seen by Voyager 2         NASA/JPL

The clouds were somewhat of a surprise after the Voyager’s views of Uranus – which was almost featureless.  The big dark spot (named rather predictably, the “Great Dark Spot”) was another surprise as were the winds (1500 mph) stirring these features around.  These are the fastest winds in the all the Planets (5) and unexpected out in the cold dark zones of the outer Solar System.

Neptune takes 164 years to orbit the Sun.  It’s a long wait for Summer, eh?  Neptune, like all Giant Planets (plus Mercury and Earth) does have a magnetic field and in fact, it is much stronger than the Earth’s.  That would seem to indicate that it has an iron inner core.  But it cannot be very large, or the overall density would be larger.  It is in fact estimated that the core part of Neptune at its center is about Earth-sized.  Most of what is above is water, ammonia and methane (CH4) ice (estimates vary for thickness).  That is considered to be its “mantle”. 

The atmosphere above that is hydrogen, helium and methane.  The white clouds you see vary in composition depending on pressure.  The higher clouds where pressures are about Earth-like (1 bar) are probably methane vapor.  Lower down and at higher pressures are clouds of ammonia, hydrogen sulfate and even water vapor, like the clouds on Earth.

How thick each of these layers might be is still open to interpretation and you can find many differing diagrams, most with no dimensions mentioned.  So, having looked at those, I will guess that the core is 4000 miles in Radius (about the same radius as Earth).

Later photos of Neptune by the Hubble Space Telescope have shown considerable changes in Neptune’s atmosphere, since Voyager.

Triton

Triton. The terrain is similar to what we now know Pluto to be like. The colors are not the same, however. That may be due to a difference in instrumentation between Voyager 2 and the New Horizon probe that looked the ninth Planet.

See this YouTube video for a “Sail past Triton  “

Triton is the largest moon of Neptune and by no coincidence, the first discovered (17 days after the discovery of Neptune, itself).  It is unique in several respects.  It is the only “large” satellite to orbit in a “retrograde” sense.  By large, I mean to say that it is near to the size of our own Moon.  By retrograde, I mean that it orbits in a direction opposite to the rotation of its planet.  That and the high inclination of Triton’s orbit seem to indicate that it was captured.  For reasons we won’t go into, it is easier for a moon to be captured in a retrograde orbit than otherwise.  Jupiter and Saturn have lots of former asteroids as moons, but they tend to be small and far away.  Triton is so close that it is being slowly pulled closer to Neptune and in several billion years will be shattered into a ring like Saturn’s.  You might expect a captured moon to be in an eccentric orbit that varies in distance from its planet, but Triton’s orbit is so close to exactly circular that the difference is not worth mentioning.  It stays at about 220,483 miles from Neptune which, coincidentally is about the same distance from the Earth to our own moon.  It orbits Neptune in 5.8 days and rotates in the same time.  That is to say, it keeps the same side toward Neptune, just as our Moon does to Earth.  Now, some of my readers are sharp enough to notice that our moon takes 28 days to orbit.  Why so different if the distances are near the same?  The difference, of course is that Neptune is 17 times as massive as the Earth, as I mentioned a few paragraphs ago.  This will be on the test! 😉   Figure D, below is a Voyager 2 image of Triton

Figure D: Triton         NASA/JPL

            All other large satellites orbit the same way and are therefore by definition, prograde.  Triton also looks quite distinctively different from most other planetary satellites, which tend to be rather uniform and crater covered (admittedly with many exceptions).  It has an atmosphere that, while very thin, has detectable clouds.  It shares the much modified and differentiated characteristics that we now know of on Pluto.  That tends to confirm the “capture” hypothesis.

            You may ask, “Just how does a passing object become “captured”? “.    There are several ways.  One would be for Triton to have collided with a smaller moon, as it passed near Neptune.  That might slow it just enough to wind up in an orbit.  As it would have collided with a prograde moon, that would be especially effective since that would almost double the velocity difference between the two and quadruple the energy delivered to the passing Triton.  That should have left a mighty crater on Triton.  While nonesuch was seen by Voyager, such a crater could have since been covered by the glacier-like deposits of Nitrogen ice (the part that looks like cantaloupe peel) that are visible in Figure D.  Likewise, that crater might have been in the darkened part of Triton, that was not visible when the Voyager went zooming by at the greatest velocity ever given to a man-made object (at the time)

A second possibility would be “gas drag” as Triton passed through the upper atmosphere.  That would seem unlikely, unless Neptune had a more extensive atmosphere at the time.  Since it may have been captured billions of years ago, that is entirely possible, but still just speculation.

            Another possibility was detailed in a paper by Craig Agnor (University of California, Santa Cruz) and Douglas Hamilton (university of Maryland) in 2006. (6)  First, I should explain that Pluto and all the other Smaller Planets out past Neptune have been designated as Kuiper Belt Objects (KBOs).  If Triton had been one of a co-orbiting binary pair of KBOs, it is possible that a pass near Neptune would have captured it, while at the same time, ejecting its companion to a more distant orbit of the Sun.  It all has to do with relative motion of the three bodies. This hypothesis has the virtue of not relying on chance collisions or hypothesized “greater atmospheres”.  This idea was made more believable by the discovery that many KBOs are indeed, binary.  Not the least of these is Pluto, who’s biggest satellite (Charon) is about one half its own size.  It has been estimated that 15% of KBOs may be binary in nature.  That a KBO could have come near to Neptune is not unlikely since Pluto itself comes nearer the Sun than Neptune as it was during the late years, last Century.  Having said that, I must also remark that Pluto is now in a resonance with Neptune that keeps the two safely apart.  I mean to say, that when Pluto comes nearer to the Sun, it is still very far from Neptune and always will be.

But, all in all, I think these guys are very near the mark with their hypothesis.

Conclusion

Neptune is another fascinating member of the Solar System and I learned a lot by researching to write this article.  I hope you find it interesting as well.  You may wonder why I do this.  Well, those of you who know me know that I suddenly have time on my hands.  It is a blessing…and a curse. ;-).  Also, I have always had a fascination with the Solar System that goes back to my days in Elementary School. 

You and I are truly fortunate to live in a time when these mysterious dots of light in the sky that were the Planets are now becoming known as Great Worlds, many that dwarf the Earth in size and complexity and others that are revealing the secrets of Nature that have been heretofore unknowable.

References

  1. Discovery: http://www.universetoday.com/21621/who-discovered-neptune/
  1. Voyager Data Rate: http://itknowledgeexchange.techtarget.com/storage-disaster-recovery/nasas-voyager-used-8-track-tape-to-go-into-space/
  1. Table of Planetary Statistics: http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
  1. Voyager details: https://en.wikipedia.org/wiki/Voyager_2#
  1. Winds: http://www.space.com/21157-uranus-neptune-winds-revealed.html
  1. Triton Capture: http://news.softpedia.com/news/How-Neptune-Captured-Triton-23313.shtml

Somewhere in Oklahoma

stevesafetyglassesJanuary 11, 2019      homepage

Many of my readers will be happy to know that I have again found employment in the Seismic Industry – as much out of friendship as of appreciation that I will not be complaining about being unemployed.  I will be somewhere in Oklahoma for a few weeks  A project in Texas is penciled in for later.  The client has rules about posting photos and project information, so I am intentionally vague.  If you are also in Seismic, you can guess who the client is.  The company may have such rules and so they will be referred to as “the Company”.  The photo below is not related to the project or the Company.  (As far as I know, the project does not extend to the sky).  This is an example of  “Sundogs” which is a pair of bright spots of refracted sunlight that illuminate a cloud layer.  This is fairly rare and I have seen it maybe 5 times in as many decades.

sundogs_crop_arrows2

A rainbow, by comparison, is both reflected and refracted and appears in the sky opposite of the sun.

Below (left) in my Personal Protective equipment.  (Yes, I will trim the beard soon) hardhatsteve

My job is driving the fuel truck. Fortunately for me, haz-mat drivers are in demand just now.    I don’t have a lot of spare time, so stay tuned!

Hasta Luego,

Steve

The Grand Ice Age

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Not long ago, one of my Road Trip Interest Group members (you know who you are) asked this question:

“When was the last Ice Age?”

The term “Ice Age” is somewhat ambiguous. Fluctuations in the Earth’s climate are extreme and take place over many periods of time.  There have been eras when the Earth was completely devoid of ice.  There have been other times when all the Earth’s oceans had completely turned to ice.  So, when was the last “Ice Age”?

The most recent time that has been referred to by that name was the “Little Ice Age”(LIA).  When exactly that was depends on who you ask.  The chart below defines the LIA as being between the years 1400 and 1800 AD.  This was a time that saw mountain villages in Europe consumed by glaciers.  The “Frost Fairs” on the frozen River Thames in London happened at these times and the story of Hans Brinker, likewise.  There is ample evidence of the LIA in art, literature and history.   That painting of George Washington un-wisely standing in a rowboat, while his men push big chunks of ice in the Delaware out of the way?  LIA, again.  Below is a graph of results for last two millenia of proxy derived temperature differences.  You see the Little Ice Age as well as what came before.

Timespan:  2000 Years

MWP_LIA
Figure 1: The Medieval Warm Period (MWP) and the Little Ice Age (LIA).

These are differences in temperatures derived from examination of cylinders of ice drilled out of an ice sheet. Where that zero axis falls depends on how much time is included in the graph.  So, these data do not tell us what a thermometer would have said then.  But, the historical record tells us that during the Medieval Warm Period (MWP) Greenland was occupied by an agricultural civilization where none at that level of technology would be possible in today’s climate.  In Alaska there are glaciers that have retreated from the Little Ice Age and uncovered immense tree-stumps still rooted in the ground.  There are no such climax forests there today.

mendenhall_Tree_Stumps
Thousand-year-old tree stump uncovered by the Mendenhall Glacier’s retreat from the Little Ice Age

They date to about one thousand years ago.  So, we know for a fact that the temperatures were warmer then than now.  There are some who imagine that this was only the case for the North Atlantic.  But, Alaska is not on the Atlantic, is it?  And ice cores from Antarctica tell pretty much the same story.

The time before the LIA was much warmer than the climate today.  The MWP was, itself just another in a series of warm periods, starting with the Minoan Warm Period and occurring roughly every 1000 years.  Below is a graph of oxygen-Isotope proxy temperature anomalies.

Timespan: 11,000 years. 

GISP_Holocene_Anotated_NO_CO2
Figure 2.  Greenland Ice Sheet Project (GISP) temperature differences derived from ice cores.

The last “Ice Age”  (without the “Little” modifier) is to be seen at the extreme left of the Holocene graph in figure 2. It is more accurately referred to as a “Glaciation” and is a part of a (roughly) one-hundred thousand-year oscillation of extreme cold followed by short periods (10,000 years or less) of warm weather.  This cycle is revealed, among other places – in the Vostok and EPICA Ice Core Projects in Antarctica.

Timespan 450,000 years

EPICA_VOSTOK_Annotated
Figure 3.  Antarctic Ice-core derived temperature differences.

You see that our current situation is an “Interglacial” age called the Holocene Climate Optimum that comes after the “Ice Age” (Glaciation). The Eemian which came before that Glaciation is another Interglacial in a long series of same, stretching back half a million years – at least.  The Holocene appears to be significantly cooler than the previous Interglacials – all of them.  (Put that in your “Global Warming” pipe and smoke it! 😉 )

While the future is not yet determined, it looks very much like the Holocene is about over and the next Glaciation is soon to be expected.

But, in all of this, there is still ice at the poles and on mountaintops.  The Glaciations seem to be the rule and the “Interglacials”, the exceptions.  Could we not say that the entire timespan above was a part of a larger “Grand Ice Age” with only the interglacial times interrupting?

What happens if we widen the time span?  Below is a graph of ocean sediment-derived temperatures.

Timespan: Five Million Years.

Five_Myr_Climate_ChangeAnnote
Figure 4.  Temperature differences derived from ocean sediments

The fact that those hundred-thousand-year cycles of the previous graph are seen lends credibility to this seafloor sediment “proxy” of temperature.  Notice those thousand-century cycles are a recent phenomenon (relatively speaking) and followed a period of 41,000 year cycles.  Before that was a much warmer time.  There is fossil evidence that those were times when there was little or no ice on Earth at all.

http://www.bbc.com/news/science-environment-12378934

Be warned that they will bring up “Global Warming” even though they can’t point to five-million-year-old Ford Explorers or make any reasonable defense of “Man-made Global Warming”.   -Steve

Quote about Antarctica:

“She recalled: “We were high up on glaciated peaks when we found a sedimentary layer packed full of fragile leaves and twigs.”

“These fossils proved to be remains of stunted bushes of beech. At only three to five million years old, they were some of the last plants to have lived on the continent before the deep freeze set in.”

The “deep freeze” referred to is when we live now!  

WELCOME TO THE GRAND ICE AGE!

It may surprise you to learn that you have been here all along.

Hasta Luego,

Steve

Ice Age Now and I-90 Rocks

I am doing research for yet another article that takes me to  Ice Age Now the blog of Robert Felix (Ice Age Bob).    Bob’s current first page features a video from YouTube called I-90 Rocks.

I have driven this route a couple of times, but I wish I had seen this video before, just so I could have appreciated the Geology I was passing through.

 

https://www.iceagenow.info/ice-age-lakes-between-seattle-and-the-cascades-video/

 

A Nice Place to Visit, But…

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Where to Live, if Not Earth

Life is in fact a very rare phenomenon, despite the fact that it surrounds most of us (in no small part with the “rest of us”).  You might think it to be common, but that is because you are a part of the commonality of it all.  Life is not common – outside of our planet, where it is common.

Some points about the rarity:

  1. The Earth is in the “Goldilocks Zone” (GZ) which means that it is at the right distance to be “not too hot and not too cold” for life. This is a well-known and rather trite fact to quote, but nevertheless true.  Depending on who you ask, the planets Venus and Mars are also in the GZ but apparently lifeless, thus far.
  2. The Earth is thought to have its relatively fixed spin axis because of the stabilizing influence of the moon. Other planets, without such large satellites are known to have violent shifts in inclination making environments hostile to life.  Mars has been suspected of major axial shifts on a short (geological) time scale, for example. Such a large satellite (relative to the planet it orbits – its “primary”) is a very rare condition and the only other example in the Solar System is the Pluto / Charon double planet.  And that planet -while extremely spin-stable – is way to Heck and Gone outside the GZ.
  3. Neither Mars nor Venus has a magnetic field like that of Earth which protects life from massive Solar and Cosmic radiation. It turns out that little Mercury does have a global magnetic field, but it’s hot dry surface is covered by a pitiful excuse for an atmosphere with not much more than vanishing small amounts of hydrogen and helium.  And the bare, igneous rocks of Mercury are basking in the glaring sunlight that is more than four times as intense as that experienced by Earth.
  4. The stable, near circular orbits of the planets that are common in our solar system are not so common in detected planets around other stars (Exoplanets).
  5. We have studied the Solar System extensively and know at least that conditions for life are extremely rare and Life has not yet been shown to exist anywhere else but on our own Earth.
  6. It stands to reason that intelligent life is even more scarce.  I submit to you that it is so rare as to be vanishingly small.

 When Dinosaurs Ruled the Earth

When I was young (that was back in the Cretaceous Era when dinosaurs ruled the Earth), very little was known of what lay beyond that same Earth, even within our own Solar System.  It was thought that conditions for Life probably existed on Venus and almost certainly on Mars.

Seasonal changes on Mars that we now know to be dust patterns were taken as sure signs of life. We are now accustomed to sharp clear images of the planets thanks to space probes and extensive image processing of telescope photos.  What was available in the early Sixties was not much more than grainy, very low-resolution pictures.  As far as Mars was concerned, the expectation of life there was still active right up until the first fly-by images came from Mariner 4 on July 14, 1964.

Atlantis Region on Mars - Mariner 4
Actual Mariner 4 Image of Mars from 1964.  Note the linear artifacts and the extremely  low resolution.       Photo Credit: NASA

 Those images showed a moon-like, crater-covered surface and the atmosphere was confirmed to be a vanishingly thin layer of carbon dioxide. Those who had held out hope for life on Mars were bitterly disappointed.  I know because I was there and this was not at all what I had been led to expect.  I am not pointing fingers, you understand.  Virtually everybody – scientists included – expected to see something like the early images of desert areas of Earth from space – with, maybe, some cactus plants (roadrunners and coyotes optional).  But, these Doses of Reality really were indistinguishable from the airless, lifeless moon and a bitter disillusionment to all.  It happened that Mariner 4 did not see the more interesting parts of Mars that later restored some (diminished) hope for life when Mariner 9 images began to arrive.

Probes to Venus sent back even worse news. Cloud-covered Venus had been expected to be a very warm, rainy, damp or perhaps ocean-covered place.  All of those scenarios were explored in stories and novels, back in the Golden Age of Science Fiction.  If that “Golden Age” phrase puzzles you, go and read these authors:  Heinlein, Azimov, Clarke and Bradbury.

Earth observations had already begun to indicate harsh conditions. Measurements from probes revealed that planet to be a quite literal “Hell-hole” with a hot, thick, dry and “crushing” atmosphere that could melt lead.  Liquid water – long thought to be a Life “prerequisite” is just a busted myth on Venus.

400px-Venera9
Actual surface image from Venus by the Soviet Lander Venera in 1975.  The probe died not long after this. The vertical “artifacts” are data packets that occasionally interrupted  the image transmission.  Data storage in those days was measured in kilobytes and so things had to be done in “near-real-time”.

While Jupiter does possess a magnetic field, it is also surrounded by intense belts of radiation that are trapped in that field.  In this regard, I have found some quotes that throw doubt on the chances of hospitable environments on Jupiter’s moon Europa – long thought (after the Voyager probes, that is) to be a good candidate for life.

NASA_jupiter-moon-europa
Europa. The lack of craters and the linear features (we call ‘em “cracks” where I come from) suggest active Geology.  Some have suggested that the contrasting dark colors of said cracks suggest biology.  That may be grasping at straws, IMHO

Some of those doubts:

A Probe called Pioneer 10 was actually the first to encounter Jupiter and there was some concern about radiation levels:

“The level of radiation at Jupiter was ten times more powerful than Pioneer’s designers had predicted, leading to fears that the probe would not survive; however, with a few minor glitches, it managed to pass through the radiation belts, saved in large part by the fact that Jupiter’s magnetosphere had “wobbled” slightly upward at that point, moving away from the spacecraft. However, Pioneer 11 did lose most images of Io, as the radiation had caused its imaging photo polarimeter to receive a number of spurious commands. The subsequent and far more technologically advanced Voyager spacecraft had to be redesigned to cope with the massive radiation levels.”   (Magnetosphere of Jupiter, n.d.)

And then there was this, which hammered fifteen more nails into the Europa/Life Coffin::

“The radiation level at the surface of Europa is equivalent to a dose of about 5400 mSv (540 rem) per day,[40] an amount of radiation that would cause severe illness or death in human beings exposed for a single day.:[41]

  1. The Effects of Nuclear Weapons, Revised ed., US DOD 1962, pp. 592–593

You might argue that there is a “Goldilocks” Zone deep under Europa’s Ice in a Salty Sea of liquid water.  Probably more liquid water than on all of the Earth. The miles of ice and water might well protect from radiation.  The idea that life could exist there is reasonable, but completely unproven. But is that someplace you want to spend your retirement?

There was also a very thorough work on the radiation dose expected for Apollo astronauts while passing through the Van Allen Radiation Belts (VABR) on the way to moon landings.  It concluded that the dose of radiation was relatively tolerable – mostly because the men did not spend much time there.

So far, places where Earth-like conditions exist are:  Earth.

Because:

  1. Almost all “Environments” off-Earth are without significant atmospheres, with way too much atmosphere or under miles of ice, submerged in salty seas.
  2. Many “Environments” off-Earth also tend to be radioactive enough to kill you in a day or two.
  3. None of these so called “Environments” has actually been shown to harbor any kind of life.
  4. In every case, these are places that many adventurous people would like to visit. But, without bringing along a complete life support system with you – including when you are “out for a walk” – they are no place you could “live”.

And Then We Get to Titan

Titan is the largest moon of Saturn.  It is the third largest moon in the Solar System and larger than planets Mercury and Pluto.  And it is just lousy with Earth-like qualities.  It has a very dense atmosphere that exceeds the Earth’s sea-level pressure by about 50%.

Looking on the Brightside of Titan
Titan in visible light. Photo credit: NASA

This first image is pretty much what Voyager 1 saw during its pass by Saturn, arranged especially to look at Titan.  It has been known that Titan has an atmosphere since that fact was discovered by Gerald Kuiper (rhymes with “hyper”) in 1944.  It became obvious then that to see under this veil of clouds would require more than the cameras aboard the twin Voyager spacecraft.  Mostly for that reason was Voyager 2 was cleared (after the successful encounter of Voyager 1 with the satellite) to ignore Titan and continue on a trajectory that would take it to Uranus and Neptune.  Had Voyager 1 failed at Titan, Voyager 2 would have followed its brother out of the plane of the Solar System, never having had the opportunity to see the last two Giant planets Uranus and Neptune.  Titan got such priority because of its atmosphere which is unique for satellites of any planet.

TitanInfraredd
Titan in Infrared light.  The colors here are – of course – “made up” since you cannot (nor can I – so don’t feel bad) see in infrared light. Having said that…does this not remind you – a bit – of the Earth?  Photo credit: NASA

This second image is from the later Cassini probe that was sent to orbit Saturn and (knowing what Voyager could not see) included an infrared camera which – with some filtering -could see down to the Titanian surface.

While there have been many learned speculations that an exotic form of life might exist that “breathes” hydrogen and exhales methane and “eats” acetylene, none has as yet been detected.  “Conventional” Life-as-we-know-it (LAWKI) does these things with oxygen, carbon dioxide and glucose, respectively.

There are indeed Methanogens (i.e., Life that makes methane) on Earth but all of them use liquid water as their “solvent” and none use hydrocarbon liquids as would be the case for the imagined Titanian lifeforms.

I have found no references that indicate the radiation environment is a problem at Titan. This large moon of Saturn is expected to have a subsurface ocean as Europa is thought to have, with the same speculations of “conventional” lifeforms and the same problems to be expected.

Titan is covered with hydrocarbons.  These are compounds of hydrogen and carbon that would be called “petroleum” here on Earth.  Methane rains down out of the atmosphere and heavier hydrocarbons – solids at that temperature – cover much of the surface resembling sand dunes.  These “organic” compounds that have that name because they are -on Earth at least – generally made by lifeforms.  I have not read any speculations that Titan’s organics are life-generated.

Titan by virtue of its distance from the sun to Saturn (being 10X that for Earth) receives sunlight arriving there at one percent of what the Earth enjoys.  The cloud cover that Titan is notorious for reduces that to one tenth of one percent. Photosynthesis would seem very unlikely.  That contributes to a big problem with the idea of Life on Titan.  Namely, the temperature, which is so very cold (call it -200 F) that liquid water is decidedly out of the question.

There are, in fact “Great-Lake-size” bodies of liquid on the surface, but they are composed of mostly methane (CH4) – which on Earth is the main component of what’s called Natural Gas.  As mentioned earlier, methane is a minor component of Titan’s atmosphere, just as water vapor is in our own Earthly atmosphere and it precipitates to the surface like same.

That would seem to wrap it up for extra-terrestrial life.  Several possibilities for environments which show a potential for life, but no evidence that such life exists.

 Whatever lifeforms we see fit to deposit…

(from Star Trek II, The Wrath of Khan, in reference to the “Genesis Project”)

TitanSUrfaceProbe2
The surface of Titan, photographed by the Huygens
Lander on Jan 14, 2005. Photo Credit: NASA

Titan’s atmosphere is composed of mostly nitrogen with about 5% methane near ground level with a trace of free hydrogen.   While Earth’s atmosphere is similar, being 80% Nitrogen – the remainder consisting mostly of oxygen with a few trace gasses – that of Titan has no free oxygen.

Again, the ground-level air pressure on Titan exceeds that which you  are currently experiencing – even as you read.  This makes Titan is the only place where walking around outdoors without a space suit might be possible.

There are a few problems with that idea, though.

  • Titan is extremely cold and would require the Walker to bundle up in arctic gear. Heavy-duty arctic gear.
  • This Pedestrian would be breathing from an air tank – like a SCUBA diver. There is (again) no free oxygen in the atmosphere. Let’s say that you use a re-breather and don’t exhaust any oxygen into the atmosphere.  Probably best considering the methane.
  • That methane (known to drizzle out of the haze you see in the distance) might require a raincoat over all that arctic gear. I doubt you would want to be soaked with evaporating methane when you go inside – where you will definitely have oxygen around.
  • The ground where the Huygens probe landed was described as comparable to wet clay. I can’t vouch for the stability or traction achievable on such a surface. Water ice would not be a problem, since at that temperature it is indistinguishable from rock. But those hydrocarbons that cover the surface are much closer to their melting points and could pose a slip hazard.  Other places – who knows?
  • Don’t let the picture fool you, it will be dark. That photo was taken with a sensitive research instrument. Remember that Titan orbits the planet Saturn, which is ten times as far from the Sun as the Earth.  Only one percent of Earthly sunlight reaches Titan and only one tenth of that is able to penetrate the clouds.  A moon-lit night on Earth might be the very best level of illumination you could expect.
  • You would need artificial lighting, especially through the roughly eight days of darkness when the sun is below the local horizon.
  • That brings up electrical generation. Solar panels would  be useless in the dimly lit haze. While fierce winds were measured during the descent of Huygens through the atmosphere, surface winds are likely  to be intermittent and not particularly strong.  So, you won’t want to  depend on windmills for power.  The probe was powered by batteries, which died after about 90 minutes.  No, you will be taking your own power supply to Titan and it will be nuclear in nature – something like a radio-isotope generator.  Every probe that made it past Jupiter yet has used such “nukes” for power.

Conclusions

Indigenous Life in the Solar System – once thought so likely – has been shown to be non-existent as far as we know.  This is despite decades of intense research toward finding such life.

There is not much to offer for Human occupation “off-Earth” , either.  Unless you want to live life completely indoors, surrounded by radiation shielding or in a space suit (much like being “indoors”)  Titan is pretty much it.

Having found this one special second place in the Solar System where some semblance of normal human activity is indeed possible, the list of activities is rather short. You won’t be farming.  Astronomy is out, but if you happen to be on the side of Titan that faces Saturn, that ringed planet might be barely visible through the haze.  Hiking is good and there might be some spectacular landscapes (not at the Huygens landing zone, I’ll admit).  Night-vision goggles might be appropriate.

There is one aspect might make it all worthwhile.  Titan’s gravity is a bit less than that of our Moon.  About 1/6th of Earth.  That combined with the thick atmosphere should make human-powered flight possible.  Not just possible, but easy!  Even if all your cold-weather clothes, SCUBA gear and “wings” weigh as much as you do, you  would still have only one third of your weight on Earth.

There is a sub-culture of misinformed people who  think that Humanity’s only salvation will be to move to “another planet”.  These folks tend to be against things like fossil fuels and nuclear power.  Ironically, if Titan (about the best you can find) is your “other planet”, you will be surrounded by petroleum and using nukes for electricity – in bitter cold and perpetual (more-or-less) darkness.

But you could fly!

Ex Scientia, Veritas,

Steve

Bibly:

Star Trek II quote:   “Instead of a dead moon, a living, breathing planet, capable of sustaining whatever lifeforms we see fit to deposit on it.” – Dr. Carol Marcus

Van Allen Belt Radiation: http://www.braeunig.us/apollo/VABraddose.htm

Mars Axis instability:  https://www.nasa.gov/mission_pages/msl/multimedia/pia15095.html#.WmOspainHIU

Venus (Venera):  https://en.wikipedia.org/wiki/Venus

Exoplanets:  https://www.nasa.gov/kepler/discoveries

Titan:     https://images.nasa.gov/search-results?q=Titan%20surface&keywords=&page=2&media=image,video,audio&yearStart=1920&yearEnd=2018

Radioisotope generator:  https://www.jpl.nasa.gov/news/fact_sheets/radioisotope-power-systems.pdf

 

Uranus: The Seventh Planet

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Uranus

(OK, Reader! Wipe that smile off your face and pay attention!)

This poor planet suffers that name that sounds like two words your Proctologist might put together when discussing your condition.  It is laughed at so often that it inspired an article by a man name DeCotis.  I cannot locate the original article but I emailed him the following message.  I hasten to point out that this text – once sent – has been augmented, improved, embellished and even illustrated over the years and especially just prior to the posting of this article.

Mr. DeCotis,

Heartiest congrats to Space Online, Billy Cox and yourself on a wonderful bit of writing about the planet Uranus. I myself have long considered the name of first trans-Saturnian planet to be a problem. This became a matter of importance when, in 1977, it was discovered that, like other Gas Giants, “Neptune-Minus-One” had rings. This was before Voyager 2 got to #7 and was accomplished by watching that planet pass in front of a star. This is called an occultation. Unexpectedly, the star dimmed several times before and after the planet covered it. Only rings could explain it since expecting that many satellites to be lined up in that fashion was improbable in the extreme. 

Knowing me to be an Astronomy student, people would ask me, “Are there really rings around Uranus?”. I understood that as a very personal and offending question and I was tempted to demonstrate the (negative) answer visually, but I refrained.

 Actually, I explained to them about the occultation, just as in the first paragraph – being a thoroughgoing Astronomy nerd.

UranusLightCurveCrop
Figure 1:  The actual light curve
from the 1977 occultation that
detected Uranus’ rings.

There was a Science Fiction B-movie about Uranus which was euphemistically entitled “Journey  to the Seventh Planet” back in the sixties*. Even as a teenager (or especially as a teenager, I suppose) it didn’t take long to figure out what they were avoiding. There was a brief movement (no disgusting pun intended) to transfer the emphasis to the first syllable but you can see (well, hear) immediately that this is a non-starter (“Urine-us”). The name would still be in the bathroom humor department and would only prompt a new round of adolescent jokes.

    It was about then that I decided that “Joe” was a nice enough name. But in order to differentiate whether we were talking about Lewis, Dimaggio, Cool, College, Blow, Six Pack or the Planet, we’d need to specify “Joe the Planet” for every reference. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Joe the Planet, Neptune and Pluto. I’ll grant you it’s a bit awkward at first but it should put an end to the pubescent snickering in astronomy lectures and planetarium shows.
Sincerely,

Steve

 *I looked it up on YouTube recently – it still stinks.

In college, I was assured by actual Astronomy Professors that this planet’s name is “your ah noose” (accent on “ah” and “noose” rhymes with moose).  The other pronunciations you may have heard are either erroneous or may be attributed to the aforementioned “bathroom humor”.

Now that we have the nomenclature issue dealt with, let’s have a look at the planet itself.

Discovery:

Quoting a NASA planet resource website{1]:

“The first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel,although he originally thought it was either a comet or a star. It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode.

William Herschel tried unsuccessfully to name his discovery Georgium Sidus after King George III. Instead the planet was named for Uranus, the Greek god of the sky, as suggested by Johann Bode.”

So, it’s “Bode’s ill” – so to speak.  Don’t blame poor Herschel for the double entendre.  Nor his sister Caroline who joined the musician turned astronomer and accomplished many discoveries of her own:

“Caroline assisted Herschel until his death.  She discovered eight comets. She also discovered several deep-sky objects and was the first woman to be given a paid scientific position…”

Early Observation

There was not much to see.  Even in the most powerful “backyard” telescopes – as late as the 1980’s Uranus was a small dim pale blueish green dot.  A “professional” telescope of that era would be required to resolve the largest satellite, Titania as a featureless point of light.  Even in those elaborate instruments, Uranus maintained its elusive nature.

“Even through large telescopes the planet often appears fuzzy and indistinct. Brightness variations are sometimes reported, the likely result of changes in the planet’s atmosphere.”  [2]

UranusTelescopeView

Figure 2:  Uranus through a large “backyard” telescope.

Below is that table of planetary statistics that readers may have seen before.

PlanetaryStatisticsTable 1: Statistics for the Planets

The seventh planet is 19 times the Earth’s distance from the Sun.

SimpleAUDiagram

Figure 3: Simple “Visual aid” to depict the distance of Uranus (big green dot) from the Sun (Yellow asterisk) as compared to that of the Earth (little blue dot).  Only the distances are to scale – not the sizes of the Sun and planets.

In size, it is 31, 763 miles in diameter (four and a half times that of Earth).  Like all the Giant Planets, it rotates quickly (once every 17 hours and 12 minutes) and it is much less dense than the “Rocky Planets” like Earth.

The atmosphere is hydrogen and helium with some methane.  Deeper down, there is a “mantle” of water, ammonia and methane ices above a rocky core.  You see in figure 3A that they have not labeled the thicknesses of these layers.  That is a sure sign that they don’t really have a clue what those numbers should be!

Internal-structure-of-UranusFigure 3A: Internal Structure of Uranus

A notable unique feature of Uranus is the orientation of its spin axis relative to the plane of its orbit (see “obliquity in orbit” in the table).  In the Uranian summer and winter the axis of rotation of the planet points almost directly at the Sun – resulting in one hemisphere in constant sunlight and the other in darkness.  This is thought to have been caused by Uranus’ collision with a large planetoid late in its formation.  The diagram below explains the situation.

UranusPhases

Figure 4:  Seasons of Uranus

Uranus was visited by a space probe only once.  It was the third stop on what was called at the time “The Grand Tour”.  As it happened, there was an alignment of the outer planets in the 70’s and 80’s such that it would be possible to use gravity assisted orbital adjustments (“the slingshot effect”) to make it possible for a space probe to visit Jupiter, Saturn, Uranus and Neptune in one long and carefully managed trajectory.  The Voyager 2 Spacecraft did exactly that and arrived in the area of Uranus in 1986.

The Voyager 2 Spacecraft        

The Voyager probes each had a main antenna that was capable of constant communications with the Earth.  This necessitated what is called a “scan platform” that held the instruments that need precise pointing and moved independently of the antenna.  The constant contact was needed because data storage was actually on a ½ inch, 8 track magnetic tape with a total capacity of about ½ Megabyte and a top baud rate of 56 kilobits per second (4).  That’s what I said – “Stone Knives and Bear Skins!” – so, real-time transmission was required for image data.”  Voyager was – despite my demeaning reference – quite advanced at the time and its imagery and other data are still quite impressive. They made the most of the technology at hand.

The image below depicts the identical Voyager 1 and Voyager 2 Spacecraft. (4) The dish antenna is 3.7 meters in diameter (12 feet, 2 inches) across.  The arm extending to the right contains the main experiments and the imaging “scan platform”.  The left arm holds the three radioisotope thermoelectric generators that provided the electric power out in the dark reaches where solar panels would be quite ineffective.  The gold disk on the “body” is the famous Record with messages and images of Earth for anyone “out there”.    Carl Sagan, whose enthusiasm for the search for extraterrestrial intelligence (SETI) was well-known had thought to perhaps include a plaque with a message engraved upon it as had been done with the Pioneer space probes.  This Record (an actual grooved phonograph Long Playing (LP) disc – only metal, not vinyl) was the idea of Frank Drake.  SETI Nerds will recognize Drake as the inventor of the “Drake Equation” which is a formula to calculate how many extraterrestrial civilizations there might be.  That’s Frank in the inset, with his equation.  I put him there to give scale to the picture.

VoyagerDrake

Figure 5: The Voyager Spacecraft        NASA/NASA website

UranusBlandVoyagerPhoto

Figure 6: A Voyager view of Uranus in 1986. 

Even the dedicated planetary scientists had to admit they were disappointed with the rather very bland appearance of the planet.  In trying to describe the feelings of the Voyager team about the mediocrity of it all, Planetary Scientist Heidi Hammel had this to say,  “…poor Uranus…poor Uranus!”.[6]

There had been observations from Earth of clouds in this atmosphere, so what’s the deal?  You will see in the diagram in figure 4 that the solstice – that point in the orbit where one hemisphere is constantly roasting in sunlight – was in 1986.  Just when Voyager happened along.  Later observations were made with (much improved) telescopes in the years surrounding the Equinox of 2007 (see Figure 4) – when most of Uranus has 8 ½ hours sun and 8 ½  hours darkness – “barbeque” mode, as they say.  Those images showed Uranus in its more “flamboyant” mood. Figure 7.

UranusEquinox

Figure 7:  Uranus near Equinox.  Note the rings (R) – now markedly evident when they are seen edge-on.

It is probably worth noting that the Voyager camera and those of the Hubble Space Telescope (HST) are almost certainly quite different in their ranges of wavelengths and sensitivities, so they are not directly comparable.  Nonetheless, we may expect more blandness from “poor Uranus” around the Summer Solstice in 2028.

I should mention that there is a lot more science involved than just the images recorded by Voyager and results from those found new and interesting features, as well. For example, the magnetic field detected is not centered on the planet core and its poles are near the rotational equator.  This was totally unexpected.

The Satellite that “Saved the Show”

One of the major aspects of interest in the Giant planets was the characteristics and history of their satellites.  With Jupiter and Saturn, the space probes entered and left the planetary systems obliquely across the orbits of the moons and could, with luck, come close to several of them for detailed examination.  In the case of Uranus, the moons’ orbits are like circles on the sky and are approached as if in target practice.  The “Grand Tour” scenario of hopping from one outer planet too the next required very specific trajectories past the planets along the way.  That, and the angle of the sun left only one chance of a close approach to a satellite and even that would see only the perpetually lit hemisphere of the smallest of the major moons – Miranda (Figure 7) It could not have been predicted that this would be by far the most interesting of all the moons and the feature we could all point to when asked by non-Nerds why all this expense and effort was spent to go look at a blue-green billiard ball – with no number on it.

Miranda

Figure 8:  Miranda

Miranda is the smallest (about 300 miles across) of the major satellites and the closest to the planet (roughly 81,000 miles).  It circles Uranus in 1.4 days and always shows the same face to the planet.  This is looking down at the South pole.  In the season when Voyager arrived, this was pretty much all that would have been illuminated.

And, it looks like it has been broken apart and then shoved back together!  Not surprisingly, that is one idea of how it came to look so.

“Scientists disagree about what processes are responsible for Miranda’s features. One possibility is that the moon may have been smashed apart in some colossal collision, and the pieces then haphazardly reassembled. Another, perhaps more likely, scenario is that the coronae are sites of large rocky or metallic meteorite strikes which partially melted the icy subsurface and resulted in episodic periods of slushy water rising to Miranda’s surface and refreezing.”[8]

Uranus has four larger satellites.  The biggest is Titania which is still less than half the diameter of the Earth’s moon.  As mentioned earlier they were not well surveyed in the fly-by, but a map of Titania’s surface appears in figure 9.

TitaniaCasma.

Figure 9:  A Map of Titania’s surface.  Again, only about half the surface was illuminated and this is the least boring part of that.

The larger satellite also has some interesting surface features.  I am reminded of my own varicose veins.

Conclusions

  1. The seventh planet turns out to be rather dull and featureless, but only for the Southern Summer. The Spring Equinox brought considerable atmospheric activity after Voyager but now detectable from the improved cameras of the Hubble Space Telescope and other modern observatories.
  2. The satellites of all the Giant Planets all turned out to be far more complex than was first imagined by Earthbound observers. Uranus is no exception.
  3. Uranus still has that unfortunate name (despite my “Joe” recommendation) but we can overlook that because we are all adults, here. Right?…Right?
  4. Update: In all that discussion of the unfortunate moniker, I neglected to mention a sports cheer, popular around the time of the ring discovery.  It goes like this:  “Up Jupiter! Up Saturn!…”
    (So much for Adulthood 😉 )

Hasta Luego,

Steve

[1] NASA Photos:

https://solarsystem.nasa.gov/planets/uranus/#!

[2] William Herschel:

https://www.space.com/17432-william-herschel.html

[3] Uranus Telescope view:

http://www.nakedeyeplanets.com/uranus-telescope.htm

[4} Voyager details:  https://en.wikipedia.org/wiki/Voyager_2#

[5] Table of Planetary Statistics:   http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html

[6] The Farthest: Voyager in Space – Netflix

[7]  Uranus Planetary Factsheet:  https://nssdc.gsfc.nasa.gov/planetary/factsheet/uraniansatfact.html

[8] Miranda in Depth – NASA:  https://solarsystem.nasa.gov/planets/miranda/indepth

The Farthest: Voyager in Space

SteveTrucker2  Homepage   DreamVacations

Netflicks:  The Farthest: Voyager in Space

TheFarthest

I don’t want to say that young people today are spoiled by modern conveniences – mostly because it makes me sound like a stereotypical curmudgeon.  But, it is absolutely true and it was true for me as well in those long-ago days when I could be described as “young”.  You, too.   And our parents, and theirs and so on, ad infinitum.  There is only one way to make young people appreciate the technological heritage they have.   The progress from a less complex technology to their time has to be described to them by us involuntary immigrants from the past.

Perhaps only an early-adopter “Space Nerd” from the middle Twentieth Century could explain the early days of the exploration of the Solar System.  That would be Your Humble Narrator and I am stepping up on this occasion to review a Netflick Video about that very subject.  I followed the Voyager missions from their launch in 1977 to the flyby of Neptune in 1989 – and beyond.

Before Voyager

Before there was Voyager, the outer planets were only vaguely known.  In 1977 there had been some probes sent to the outer planets – most notably the Mariner and Pioneer probes, which were not insignificant.  But, this documentary is an appreciation of Voyager – the “Game Changer” in Solar System exploration – and its very momentous accomplishments.  It was the most ambitious and significant exploration of the Solar System of that time and the facts and images gathered are a fundamental part of planetary science to this day.

Because Jupiter is the largest and nearest – at “only” five times the Earth’s distance (One Astronomical Unit (AU)) from the Sun – it was the best known.  Even at that, all that was known was some bands of clouds and a “Great Red Spot”.    We knew that Jupiter had four large moons.  Your average Astronomy Nerd – like Your Humble Narrator – could drag the telescope out of the Garage and show you the Bands and the Spot and the four moons.  He would tell you their names – “Io, Europa, Ganymede and Calisto” – and show you four dots of light surrounding a small dimly striped Jupiter where the Great Red Spot might be barely visible.

The more enthusiastic Nerd will have an even bigger telescope and will almost certainly show you Saturn.  He will twist your arm (literally, if necessary) to show you Saturn!  That is because Saturn is the stunning little toy in the eyepiece that everybody loves to see.  They might look at a picture made by a great observatory and appreciate it, but when they see it in a telescope with their own eye*, it is always a stunning epiphany.  Saturn’s largest moon Titan and a few of the smaller ones are visible in a large amateur ‘scope   About twenty years ago, I showed my mother Saturn and Titan, Rhea and Tethys.  It is a great lumbering 12 inch Dobsonian that has no clock drive to track the planet.  I had to constantly re-adjust the aim and then tell Mom, “Okay – look quick!” and duck out of her way.  She could glimpse Saturn for a scant few seconds until the Earth’s rotation took it out of view.  Then I would step back in to find it again, describe what to look for and where and jump back out of the way.  She was fairly impressed when I told her that very few people on Earth – one in many millions, perhaps – have personally looked through a telescope and seen these.

*With very few exceptions, telescopes are “monocular”.

The next two targets of Voyager Uranus and Neptune were – even with the best telescopes of the day – were still not much more than small indistinct discs of light.

GoingwalkaboutMorseI told you all that so I could tell you to see “The Farthest: Voyager in Space” on Netflix.

The Story of Voyager

The story begins with the engineers who built the thing.  Things, actually – there were two of them.  What they modestly describe is really a miracle of concentrated effort and talent, innovation and adaptation.  Those engineers and planetary scientists that participated in the effort are interviewed, but not in any simple question-and-answer format.  Rather, their responses are woven into the narrative to make a smoothly-flowing saga.

The tale continues. Once the craft were assembled and packaged on their rockets, they were summarily thrown off their native planet – never to return –  in dramatic, suspense-filled launches.

The spacecraft encountered, recorded and sent back to Earth discoveries that, on the one hand confirmed long-held ideas of the nature of the Solar System.  On the other hand, they relayed stunning new revelations that nobody – in their wildest dreams – had imagined could exist.

JupSatUraNep

Each planetary encounter at Jupiter, Saturn, Uranus and Neptune -and the decisions and the problems – is chronicled and described by the people involved.  There is archival video from the encounter operations where you will recognize younger versions of the interviewees.  After Neptune, the continuing mission of the probes is described.  And all through the narrative, the sounds and pictures of the famous “golden record” (a Human message to the Universe) are heard and displayed.

Doubt me if you must, but this story is a compelling drama, complete with comedy, tragedy, euphoric glory and devastating failure. A well-written, well-produced timeless chronicle of a stunning achievement for all mankind.

This video has become my new “Saturn” moment.  I dragged (figuratively, figuratively!) my Wife to see it with me and she was fascinated by what she had never known.  I am working on appointments to watch it again with First and Second Sons.

Hasta Luego,

Steve