From the WordPress site.
Interstate 70 Rest Area Mile Marker 130, Licking (Yes, that’s what it’s called) County Ohio – November, 2016
To reduce chronological confusion, when I am writing “in real time” I will put that text in italics.
Normal font means I am describing something that happened a day or more ago.
At times, it seems that I don’t have a moment to spare. After Denver, I took a load of meat from Kansas to Maryland. I spent a lot of time in Maryland a while back while I was “Shipwrecked” at a Peterbilt Shop.
The delivery in Maryland was in three parts. The first was a big box chain distribution center that was no problem. The second was a Kafka Movie experience. I arrived an hour early at Three AM. I was left waiting for a door. That is to be expected for early arrival so I was not alarmed. I got a door about 90 minutes later, backed the open trailer in and turned in my paperwork – all as expected. After that, the driver waits for the green “docking light” to turn red. This indicates that the unloading has begun and the trailer is “latched” to the building to prevent the trailer from moving. All this would be normal.
But, after an hour, the light was still green. Not normal. I went back to the receiving office and to ask politely if there was some problem or misunderstanding. I was told to “just wait for the call”. On the way back to the truck I notice that eight of ten truck drivers near me are also still looking at green lights in their rear-views. I waited until it was obvious that I would miss my next appointed drop at Seven AM and called to re-schedule. I told the receiving office at stop #3 (a quarter mile away) that I would need at least another hour. She asked where I was. When I told her stop#2’s name and address, she gave me two and one half hours. That made me think she knew something I didn’t. 😉
Drivers generally don’t bother each other in loading docks because they are all busy with paperwork or sending reports or trying to get some sleep. But, I happened to catch a neighbor (also sitting at a green light for over an hour) and he told me that this is normal for Drop #2. At last the light went red and unloading began. They were through in time for me to barely make the new appointment at Drop #3. So, with paperwork in hand and a song in my heart I started the engine and made ready to leave. The light was still red. Again, my trailer was clamped to the building. I could not leave unless I dragged the building with me. A polite reminder call to the receiving office and I was assured I would be released momentarily. I called again fifteen minutes later and said, “I don’t mean to be a pest or anything, but…”
I was at last released to arrive double-late at Drop #3. By this time, my door had been given away and I had to wait another three hours for a door – not unusual for late arrivals.
During the early hours at Drop#2, I received a new load assignment. I reviewed the information and made a trip plan. This opportunity expired during the delay at the door. Another assignment went exactly the same way while delayed at Stop#3.
Above: I don’t have any pictures that relate to this post, so this is a photo of Jill’s recent directions at highway exits. As you see, Jill has gone all Schrodinger’s Cat on me – actually telling me to stay and go at the same time. This went away after a recent software upgrade.
Interstate 94 Rest Area at mile 161 near Ann Arbor, Michigan – 3 AM 11/13/16
I am on a tight schedule two loads in front of the narrative. I will find some time soon (another 34) to catch up. Meanwhile, I have these snippets of time to advance the story.
All told, I spent over ten hours in Maryland planning trips that were later cancelled, interacting with receiving personnel, filing reports, doing paperwork, moving the truck around, waiting for a door or waiting in the door. I might find that sort of activity more interesting and challenging if I were actually paid to do it.
From Maryland, I was sent out to the end of a Peninsula where truck stops are apparently not socially acceptable. There is a chicken plant down there where I was assigned a load. No fuel or parking so it requires preparation and lead time and back without running out of fuel or drive time. It is a lot like Free Diving where one holds their breath to descend to great depths and then return to the surface. This chicken plant is an ugly, unorganized place where they tell you to “drop the empty anywhere” and your full trailer is somewhere on that same lot. I walked around on foot through the muck on the parking lot that also includes thousands of feathers and other organic material from the hundreds of seagulls hanging out around the yard.
Exiting the yard when my load was ready was a choreography. I had to hook the trailer and drag it around to the scale, past all the randomly placed empties and loaded trailers. The scale exits back to the yard, so we do it again to get out the gate. I rehearsed the sequence on foot, making sweeping motions where I would swing wide to avoid collision. I’m sure the yard personnel thought I was some sort of latter day Mr. Monk and avoided me as a result.
Detroit Receiving Yard – 7 AM 11/13/16
Checking in at the guard shack here in Detroit left me with instructions to wait for someone to come find me. I parked where he told me and looked in vain for a receiving office. When my appointment time came I called that number we have for contact and sure enough, there was another door, outside the yard fence where I should have gone. The guard is just a guard and has nothing to do with Receiving. Now that someone in operations knows I am here, I should get a door soon.
Back to the chicken load from Virginia Shore to Iowa.
My work cycle was now reversed from what works. I was getting up in the late afternoon and driving until early morning. Arriving at truck stops and rest areas exactly when they can be expected to be overflowing into the streets and out onto the Interstate shoulders. The trick of passing up the rear-enders to find new vacancies works about half the time. If it fails, then there is the exit ramp. If that is full, the next stop may be only 30 to 50 miles away.
Now Westward bound, I was chasing the sunset instead of fleeing the dawn, as I would prefer. Jupiter appears above the sun and dominates the sky after dusk. When I turn around and head back East, I will see (low to high) Mercury, Saturn, Venus and Mars above the predawn Sun. Venus should be obvious, Mercury may be lost in the Sun. Saturn is faint, being on the far side of the Sun. Mars can always be recognized by its reddish color.
Delivering my Giant Containers of Chicken (one per pallet, 20 pallets – 39,000 pounds) was a pleasure. The Receiving staff was pleasant and informative. The lady of “mature” years who signed me in took me to a window to show me where to park and described what to expect from the loaders. She directed me to the “facilities” and offered me coffee. The doors had a half mile of run-out in front of them making the easiest docking in the world. After I left, I found no room at the inn at the local truck stop, but there was a Walmart down the street with other trucks parked. I joined them and spent about $90 re-stocking the ships’ galley before spending a restful 10 hour break in the same eight parking spaces.
From there to Ottomwa, Iowa to take on a load of pork. I dragged it to Michigan and I thought I was in the twilight zone when I pulled into the chosen area where I expected an 8 PM crowd and found only one other truck in the midst of about 30 pull-through diagonal spaces. A third truck arrived and I asked the driver about this phenomenon. She said it is like this every weekend.
Normally I fill up my water bottles at rest areas. I found the water fountains stained with mineral deposits and the water was not worth collecting. When stainless steel fountains are stained, be very afraid. Flint, Michigan is just down the road from here. You would think they might use water softeners and filters at rest stops and other very public places. Evidently not.
I called from Detroit Receiving again after an hour parked. I’m next, they tell me.
Vermillion Service Plaza exit 139, Interstate 80, Ohio – 1 PM 11/13/16
The Detroit drop is complete and I have moved to a place 20 miles from the Ohio drop. I’ll leave at 3:30 AM tomorrow to complete that one and drive 120 miles to another appointment at noon.
This brings us to the point where the two narratives merge into the present.
Over The Road,
Some of you readers are aware that I have been working as a Telescope Operator at the George Observatory at Brazos Bend State Park. There are three domed instruments that are open to the public for viewing on Saturday nights – weather permitting. I get to operate the smallest to these — a 14 inch Schmidt Cassegrain instrument. For non-Astronomy Nerds, the 14 inch number refers to the diameter of the mirror that is inside the big, black tube.
We might have forty or more visitors on an average night, but even so there are occasional intervals when I can make some photographs. There was one night when the atmospheric conditions made the “seeing” miserable, but I still managed to catch some images of Saturn. Most detail of the planet and rings was lost, but a couple of satellites were captured in one long time-exposure where the planet and rings were overexposed. You might need to zoom to see the moons.
More recently, on a night with better seeing, the Orion Nebula was captured in a series of different exposure times. I include two below.
There are methods, these days, to stack (combine) multiple images and get far more impressive results. I am looking in to that.
Like many people, I have an interest in the idea that the Earth has been the victim of a multitude of asteroid impacts, over the Eons, and might become targeted again. Unlike many people, I have looked up the orbital parameters and mass for some near-Earth asteroids and applied Kepler’s Laws to estimate what effort might be necessary to change the path of a potential Earth-impacting planetoid.
What I found was that it would be extremely expensive, but within the realm of possibility. Well, damn the expense! If it can be done, we would do it or suffer the consequences. I used the Cassini Saturn-orbiting probe as my example of “current technology”, which tells other Space Nerds how long ago that activity occurred.
The scenario was that we should launch a mass the size of Cassini with that probe’s velocity to collide with the asteroid – not to blast it into pieces, because that would not be nearly enough. Rather it would be to change the orbit – to delay (or advance, works either way) the arrival by one Earth radius. The idea being that when the threatening asteroid got to its intercepting point, the Earth would not yet (or no longer) be there.
Figure 2: Cassini: Now, I don’t mean to ram billion-dollar space probes into asteroids. I just used this as an example of what mass has been launched before – at what velocity.
The truth is that I don’t remember* how many “Cassini masses” would be required, but I seem to remember that it was at least 20, so we will go with that. After all (and as I pointed out at the time) Boeing would be happy to launch 20 measly rockets, just to have the “Boeing Saves the World” press coverage. That choice of Boeing* is another indicator of the age of this calculation. Today, I reckon SpaceX would be the contractor of choice. Tell me Elon Musk wouldn’t be happy to get that media coverage!
There are a lot of details that make this far more complicated than I might have led you to believe. For example, Cassini only got out to Saturn by making “slingshot” passes of Venus (twice), the Earth and Jupiter. It is actually the velocity that is the critical element and a very great deal of that was gained by those encounters. I have assumed that we learn of impending doom long before the pending event, since Cassini was launched in 1997 and arrived at Saturn in 2004.
It also took a long time to engineer the craft and develop the mission but, we imagine that development of a simple impactor would be vigorously expedited, given the circumstances. It might be better to just send a big bag of sand. And one might entertain the idea of releasing the sand from the bag just before impact to spread it out some. See, you don’t want to make a lot of fragments, since those will undoubtedly have a variety of orbits, some of which might still intersect the Earth.
One complicating problem about all this was pointed out by Carl Sagan. If I change the orbit of the asteroid and don’t do the job in “one fell swoop”, the effect is to move the location of impact, not into space, but to another location on Earth. Sagan compared this to “walking” a very large Nuclear bomb across whatever countries are between the initial impact zone and the “edge of the planet”. Carl had in mind some kind of rocket placed on the asteroid that would gradually move the impact zone. I checked that idea and it requires a lot of “rocketry” and so lots of logistics and assembly and fueling. My simple-minded “throwing rocks” (or sandbags) scenario was a lot less complicated but still not in the “one fell swoop” category.
Now, I told you all that so I could tell you this:
I am currently attending the Lunar and Planetary Science Conference. This is the 50th such conference and it is no coincidence that the moon landing was also 50 years ago. The Conference “proper” has yet to start. I have just finished the second of two sessions of what is called the Microsymposium 60 – a “preliminary” event, like the no-name band that opens for Pink Floyd*.
Figure 3: Lunar and Planetary Science Conference
Microsymposium 60 (Spellcheck fails miserably when they make up words like that, so I copy-and-paste these things) was all about how there is now a “Moon Rush” of private contractors and government effort to return to the moon. That sort of news is usually hyperbole*, but this time it might be different. Government will probably not come through anytime soon, but there is a moon lander by a private company that – if all goes well – will land on April 11…this year! I just learned that in Microsymposium 60.
Figure 4: Space IL Beresheet probe. This was a Lunar X-Prize entry, but the X-prize expired un-won. They went on anyway.
Other private companies have been making moon landers, too. They are ready to go and showing their wares (along with Instrument Makers) to eager planetary scientists today and throughout the Conference. In case you think these are lightweights, among the presenters were Lockheed Martin and SpaceX. Some of the lesser known companies have made equipment and whole probes before. A company called Masten has made over 600 flights, (many with landings) to date.
Figure 5: Masten
Microsymposium 60 will be the subject of yet another post (or magazine article). This post is to reveal where I am about to go listen to technical presentations for three hours this afternoon. Notice (below) that this is for “the media”. Yup, I am “credentialed” Working Press (it says so, right here on my plastic badge) for the entire Convention.
Workshop for the Media on Planetary Defense
at the 50th Lunar and Planetary Science Conference
Everything you’ve always wanted to know about near-Earth objects and planetary defense: a workshop for journalists and science writers. (that’s me! – Steve)
Sunday, March 17, 3:00 p.m. – 6:00 p.m. (4:00 p.m. EDT, GMT -5)
The Woodlands Waterway Marriott Hotel and Convention Center
The workshop is free but places are limited, so registration is required.
In this three-hour workshop, experts will report on the methods and status of finding, tracking, and characterizing near-Earth objects (NEOs) and planning for planetary defense. Plenty of time will be provided for questions and discussion.
Journalists and science writers will have an opportunity to learn about such developments as:
- Progress in ground-based optical and radar observations of near-Earth asteroids and comets.
- Advances in modeling and understanding atmospheric, land, and water impacts of NEOs.
- Current understanding of NEO characteristics.
- NASA’s Double Asteroid Redirect Test, the first mission that will demonstrate an asteroid deflection technique (the kinetic impactor).
- Functions of the Minor Planet Center, the International Asteroid Warning System, and the Space Missions Planning Advisory Group.
- The first test of the global asteroid-impact warning system and plans for a second test.
- Interagency and international cooperation on planning for planetary defense.
- The status of planning for a dedicated, space-based asteroid detection telescope.
Experts on hand will include:
- NASA Planetary Defense Officer Lindley Johnson
- NASA NEO Observations Program Manager Kelly Fast
- NASA Planetary Defense Coordination Office Program Executive Rob Landis
- NASA NEO Observations Program Scientist Michael Kelley
- University of Arizona Associate Professor, Small Bodies, Situational Awareness, Vishnu Reddy
- Near Earth Object Camera (NEOCAM) Principal Investigator Amy Mainzer, Jet Propulsion Laboratory
Saturday March 15, 2019 8:30 AM to 1:30 PM One, Two, Three, Etc. is an arts and craft company in Houston that offers Peruvian jewelry, ornaments and accessories.
At the The Heights Epicurean Farmers Market 1245 Heights Blvd 77008
This is yet another post that was languishing over at the WordPress site.
September 27, 2016
“Stay away from Dallas”.
This sage advice is from me to myself. I am in Denton, Texas, “sitting in a door” awaiting the unloading of produce from California. A “preplan” has just come across the satellite link that tells me my next load will be picking up at the Coca Cola Syrup Plant in Dallas. The destination is Denver for 840 miles – a two day trip that will undoubtedly be stretched into four days, as we discussed in earlier Chapters. But, I accept the load because I really have no choice.
Now for the Rest of the Story: A note from someone named Billy says I should bring my load to the Yard. So, you see the lesson is clear: Stay away from Dallas.
I called my Driver Manager to Confirm this – since I have no idea who “Billy” is – and, yes I have to make an appearance in Purgatory (not the ski resort (NTSR)). One reason is a physical exam , after the third such in the last nine months. I passed them all, by the way. The first and third exams had a one year renewal. But, since my livelihood is apparently a low priority, I have to go in for a forth. Today is Friday. Since it its nearly 4 PM and the light is still red – meaning I cannot yet leave the door – there is no way I can get there during “office hours” – and I suspect the Doctors do not work on Weekends. So, unless I miss my guess, this will be three or possibly four more days of ungainful unemployment.
The unloaded message from Target has come. The light is still red but when it changes I can go to Coca Cola and then to Purgatory (NTSR). Meanwhile, my clock has run out completely and utterly. The Coca Cola Plant policy is – as I many times said as a bartender – “You don’t have to go home, but you can’t stay here.”. I had told the shipping clerk that if I could not be loaded in two hours, I would come back in the morning. That particular clerk was not among the Polite and Helpful Shipping Personnel of whom I have written before. He ignored my advice completely.
While the clock was ticking down, – in anticipation of what finally did occur – I had called “Night Safety” and asked for advice. Their sage counsel was basically this: “Call me when you actually fall off the cliff.”
One thing I have learned in this occupation (maybe I should start a list) is: When you have an insoluble problem, ask the people in the plant because they have seen this a hundred times before,” The first choice is the Yard Tractor Guy, If he is unavailable (being very busy), ask the man who brings you your paperwork. That helpful and cheerful individual clued me in to some big parking lots to be found about a half mile away. I chose a Lowes lot, because, on the way in I had stopped there to confirm directions. There was an old trailer parked there that I could hide behind to avoid any questions from the Local Constabulary.
I was officially “off duty” and I creeping the truck at 10 MPH – flashers going – I manage to stay that way to find the Lowes. I also find another truck who has taken my hiding place behind the abandoned trailer. One look by the loading docks finds tow-away warnings with certain words in bold font. There was, however a string of about 10 conventional parking spots – off the side of the building, but in full view of the street.
Calling Night Safety is no longer useful since they may well tell me to move. And I have no confidence in their advice now anyway. So, I mentally prepare my defense for the sin of parking.
- That sign that says no parking anytime (with emphasis) cannot possibly apply to me here because: What are these spaces between the eight lines that I am parked over? That’s right – “Parking Spaces!”
- Yes, I have taken nine of them, but I can point to hundreds of empty spaces out in front of the store.
- I have every right to park here, because I am a customer. I need to buy a screwdriver. I find that the store is closed now, but I don’t mind waiting.
- I will be leaving at 4:30 AM. Please tell me if the other spaces fill up before then.
September 27, 2016 Pilot truck Stop outside Amarillo, Texas
Back in Purgatory
The “Yard” is a singularly depressing place. Every driver there is earning nothing. When I arrive, I am handed a list of tasks I must accomplish in order to escape Purgatory (NTSR). I find that I will be here at least three days between safety lectures and the physical exam. A few of the safety items are accomplished before the office staff goes home at noon, Saturday. The remainder must wait until Monday. With few exceptions, every driver here is trapped without transportation. You don’t just drive these trucks when you think you want to go somewhere – you must be “dispatched” and you won’t be, until your list is complete and signed off. There are two “loaner” cars for the untold hundreds of drivers. The waiting list is three hours long and the car must be returned within one hour. The entirety of Saturday afternoon was consumed with one trip to Walmart. This was urgent, since the truck’s food supply has dwindled to “Spam Rations”.
Sunday was shaping up to be especially dismal, having literally nothing to advance the cause of getting out of Purgatory (NTSR). I thought of my son Benjamin now attending college classes about 50 miles from Purgatory. I would like to visit him, but that would be a trip out of the one-hour-loaner-car range. A taxi is financially counter-indicated in my current circumstances. Fortunately, Dallas has an extensive mass-transit rail system that nobody seems to know about. I hatched a plot to make a Great Railway Journey to The University of Texas at Dallas (which is really in Richardson, Texas). Some research came up with this route:
Take the 597 bus that stops right in front of Purgatory (NTSR). That takes me to Lawn View train station. From there I take the Green line downtown and transfer to the Red Line which takes me almost to Plano. I get off at City Line/Bush station and take the 883 UTD shuttle. About two hours and fifteen minutes each way. Since the alternative was to cool my heals in Purgatory, I decided to make the journey. The price was right, being a five-dollar day pass. I noticed that it was good until Three AM the next day. I am quite sure this is because bars close at Two.
Above: The trip plan to UT Dallas. The Astute Reader will notice that this is actually a picture of the return route.
Above: The Green Line station at Lawn View
Above: Benjamin’s Dormitory Building. His window is third from the left on the second floor. Like almost every building on Campus, it is very new.
Above: The lobby at Benjamins Dorm.
So, instead of a depressing and lonely vigil of hopelessness, Sunday had become an interesting trip to spend some time with my beloved son. There is, after all a reason not to avoid Dallas. For this much-needed relief I was truly thankful.
Benjamin took me to lunch and then we went shopping at Walmart. That was yet another bus ride. The stop outside Walmart was littered with abandoned shopping carts. I, your humble narrator, pointed out (ostensibly to Benjamin, but meant to be overheard by the mass of scholars there assembled) that the arriving student-shoppers could choose a cart from this stash and take it in with them. I set them an example, but none of the “Future of America” saw fit to join me. They did select carts at the door, however. And no doubt they added to the collection at the bus stop on the way out.
Above: The bus stop at Walmart
Above: City Line / Bush Station, on the way back to Purgatory. The emergency equipment was there when I arrived for some poor commuter who somehow fell and was trapped between the bench and the partition that you see under the awning at left. I didn’t rush over and photograph him, since I am sure he was dying of embarrassment, in addition to the nasty bruises I noticed as they put him in the ambulance.
There is some good that comes of this unwilling visit to Purgatory. Mechanics replaced the duct taped improvised oil filler cap that I made from a fish oil pill bottle with a real oil cap and replaced the lost oil – five gallons of same. They also repaired the tractor suspension airbag that was leaking. While I was in safety class and getting my blood pressure checked, they replaced my cracked windshield. They transferred the EZ pass for tolls and the Prepass indicator for weigh stations to the new windshield. One particular windshield-mounted item did not make the transition and I won’t miss it one bit. (Update: Since I am no longer employed by Stevens Transport I can tell you that the item in question was the “1984 – Big Brother Camera” (84BBC) that watched over me for those months before the windshield was replaced. I did not mention it before because, in my Paranoia, I imagined that Stevens might read my blog and call me again to Purgatory for a replacement of the 84BBC.)
There was also a problem with the air-suspension seats, which tend to leak down while the engine is off and leave the driver looking eye-level at the steering wheel. They did not get to that problem of the leaking seats but I can live with those. When the engine is running the seats rise to comfortable height. It would have taken longer and I needed to get on the road to actually earn a living.
On Monday, after all my assigned tasks were complete, I received a load assignment to take bottled soft drinks to Denver.
Over The Road,
My posts are free to read, but the site costs me a bundle to maintain. If you like what you read, help with that is appreciated.
Saturday May 25, 2019 8 AM to Noon One, Two, Three, Etc. is an arts and craft company in Houston that offers Peruvian jewelry, ornaments and accessories.
At the The Farmers Market on Grand Parkway
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 “
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 they 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 is – in part – 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.” That configuration had proven troublesome on Voyager II at Saturn and data were lost. Voyager was – despite my demeaning reference – quite advanced at the time and its foundation of observations and 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!
Figure A: The Voyager Spacecraft NASA/NASA website
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.
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.
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.
- Voyager Data Rate: http://itknowledgeexchange.techtarget.com/storage-disaster-recovery/nasas-voyager-used-8-track-tape-to-go-into-space/
- Table of Planetary Statistics: http://nssdc.gsfc.nasa.gov/planetary/factsheet/planet_table_british.html
- Voyager details: https://en.wikipedia.org/wiki/Voyager_2#