Urban Astronomy – Comet Leonard

Unmasked and Unafraid

Posted December 19, 2021

The night sky is pretty much a mystery to most City Dwellers.  The glare of city light drowns out all but the brightest stars – and planets don’t do much better.  If you are interested, I can tell you where to look to see these far-off worlds.  If you were not interested, you would have stopped reading after the first sentence. 

So, at this point, I know my audience. 

Comet 2021 A1 – Leonard

There is another “Eyes Only Visible” comet to be seen in the Southwestern sky, just after sunset. The current magnitude of Leonard is +4.6, so in the city, it is only just visible and would be better seen with binoculars.  Once again, do not use telescopes or binoculars to view the Sun – blindness will result!  I said “after sunset” so you should be OK if you listen to me. 😉

As is usual in these cases, the comet gets brighter not only because it gets close to the Earth.  It also gets brighter because it gets closer to the Sun.  The third brightening influence is the material that the closer sun vaporizes.  That stuff makes a cloud around the comet and is it also partially blown away by what is called the Solar Wind – in a comet’s tail.

Figure 1, above shows the location to view, which is conveniently close to Venus, which is the brightest thing in the sky.  If you can see the Planet, you should be able to see the comet – although you may need those binoculars to do so.  

We have had very cloudy weather here in Houston (today, Dec 19) is “Mostly Cloudy” at 4 PM, changing to “Cloudy” around Sunset at 5:26 PM.  Tommorow at Sundown the prediction is “Mostly Cloudy” and the comet will have moved slightly relative to Venus.  These next few days are literally the last chance to see Leonard, as it is on a hyperbolic orbit – which is a nerdy way to say that it will never return to the Solar System.  (Please see figure 2 below)

Figure 2. Comet Leonard is diving through the Solar System, never to return.

For readers not in the Houston area, just look for Venus (and Jupiter for orientation) and use the chart above to find the comet.  We are lucky to be able to have the two brightest objects in the sky (now that the moon is not around in the early evening) as our reference points.

Hasta Luego,


Uber Alley – The Golden Orb

The following photo is of an abandoned building in Southwest Houston. This place is a local legend and when I pick up a passenger who lives nearby, I ask if they know anything about it.

UPDATE: One of my sharp readers found that this building is a part of a failed Taoist Temple and is only about 20 years old. But, I was “on the money” with the Deportation bit and my “Golden Orb” title was close to correct. See complete description at the link below:

So far, I have one “failed shopping center” and three “Buddhist Temple” stories. At least two of the Buddhist theories mention that the owner/builder was deported. There are some fenced-off lots around this place with similar fencing and “style”. The building has been there for at least thirty years that I know of – and perhaps a decade or two before. If Readers would care to look it up, it is found at this intersection:

Hasta Luego,


Uber Alley – Frozen Palms

Published April 18, 2021

Many of you in the Road Trip Interest Group*  live in Houston and experienced “The Freeze” of February 2021.  One thing you cannot have failed to notice is the dead palm trees that are sprinkled like brown confetti in every part of the Houston.

*My email list for article alerts.  Go to “Contact”, put Road Trip in the subject line and include your email address.  You’ll get a Blind CC message with a short description and link once every couple of weeks, max

Figure  1:  Variations of this scene are repeated thousands of times across the Greater Houston Metropolitan Area.

   The devastation is frequently in commercial zones, especially at Tropical Wannabe bars and restaurants.  I do not dispute that these trees do supply a pleasant view while partaking of libation.  However, it has become obvious that such plants are not appropriate for the climate, even though they may persist for years.   This place may have been vacant at the time.  I doubt if insurance would pay off for the landlord.  Such trees are an asset in a patio bar and the cost to remove them will be substantial. 

Precious few of these plants will survive, but I have seen a few, especially where the plants and trees were close to buildings or where the residents had actively protected the subjects.

A good example can be seen in figure 2, below.

Figure 2:  These houses are a few blocks apart in the same neighborhood.  Note the vivid difference in outcome.  I take the liberty of warning young folks that the “drop-light” strategy requires incandescent light bulbs – NOT LEDs!   Such attention to the trees in figure one would obviously be impractical. 

There is a big stand of (dead) palms at I45 South and Broadway.  A sad sight, but magnificent in its scope! I’ll try to get by there for a photo-shoot.

I too, worked hard to protect our crop of Aji Amarillo Picante.  Alas, all was in vain!

Hasta Luego,


Near Earth Asteroid 2021GW4

Published April 11, 2021

Once again, we – on Earth – will be passed by a Near-Earth Asteroid.  This time on April 12th. Don’t worry!  Its nearest approach will be about 38 thousand kilometers (23,800 miles).  For reference, the diameter of the Earth is about 8000 miles. The size of this is a rock that you could hide a Ford Expedition behind.

 Near Earth Asteroid…Date……….Miss Distance…..Velocity  (km/s)…..Diameter (meters)……

Figure 1:  Parameters of Near-Earth encounter with 2021GW4

Figure 2:  Orbits of Earth, the Moon and 2021GW4.  These are calculated without the Earth’s gravity effect on the asteroid’s orbit.  The red line suggests what might happen in reality.

The question on everyone’s lips is always what will happen IF this asteroid were to collide with the Earth.  It will not do that, OK?  

People just love to imagine catastrophe and asteroids are their greatest opportunity.  So, I have developed a macro to calculate such a disaster given the mass of the asteroid and the relative velocity of that asteroid with the Earth.  Now, there are many variables (also referred to as “parameters”) that effect such calculations and I have made many assumptions – based on “average” values of density – and so forth.  So, if you calculate a different number, please let me know – and show your work!

With all those disclaimers, I will say that the asteroid’s impact – if its course were to coincide with the position of the Earth (which WILL NOT HAPPEN, by the way!) –  would generate an explosion equivalent to 1.3 kilotons of TNT.  This is calculated by the Kinetic Energy using the estimated mass of the NEA and the velocity from the table in figure 1.

 For reference, the bombing of Hiroshima yielded an explosion estimated at 12 to 18 kilotons.  For an extreme example the “Tsar Bomba” detonated by the Soviet Union in 1961 yielded about 50 Megatons (50,000 Kilotons).  So, we have already done far more damage on our own than this particular object could heap upon us.

Ex Sciencia, Trivia


Urban Astronomy April 6, 2021 (about 0630)

Published April 5, 2021

The Earth has gone around the Sun again and Jupiter is in the morning sky once more.  The Urban Astronomy Cursor (AKA, The Moon) is again indicating that planet around 6 to 7 AM.  Shortly thereafter the Sun rises.  Readers will remember that the “last time around” Jupiter and Saturn were close neighbors.  Now more distant, they are. You will find Saturn at a 45 degree angle up and to the right from Jupiter.

The waning crescent Moon points out Jupiter and Saturn.

Harrison Schmitt – Geologist & Lunar Astronaut

Published March 9, 2021

I have seen this impressive speaker at the Lunar and Planetary Science Conference at least twice.  He strikes me as near to a “genius” as is possible for a human being.  I seem to remember that someone said, “Genius is one percent inspiration and 99 percent perspiration.  Certainly that will describe this Apollo 17 Astronaut and the first Geologist to stand on the Moon. 

As the video linked will reveal, he spent his time traveling to the moon looking back to analyze the weather of the Earth as it receded from the Moon-bound spacecraft.

I was not at this particular LPSC conference, but I am glad to have the video to appreciate the talk given by Schmitt, who never fails to impress, whenever I have seen him in person.  Among other subjects, Schmidt discusses:

  • Refined navigation – just a few orbits before –  that allowed a precision landing.  
  • Very plain, abundant and visible evidence of the lunar landing from Lunar Orbiter satellites decades after the landings – including rover tracks, footprints and long-lasting American flags that still cast shadows.
  • Body work on the Lunar Rover and why the lunar rover could not get stuck. 
  • Engineering challenges for future Moon work including space suit design and “roadwork”.
  • Sampling techniques and results including the famous “Orange Soil!”.

Figure 1:  Harrison “Jack” Schmitt December 1972 (left) and March 2017 (right)

After that is a lot of arcane Geological detail and the average viewer may be forgiven for fast-forwarding.  My readers, however, are above average and should be interested.

After that are the questions and that is required viewing, readers! 

Schmidt is very good at explaining this stuff.

No description of Lunar Geology* would be complete without a reference to Eugene Shoemaker, who was the premier enthusiast on that subject and would have been the first Geologist on the Moon, had it not been for a medical disqualification.  The first question to Schmidt (around 59 minutes) was about Shoemaker and the reply was, “I wouldn’t be here were it not for Gene Shoemaker”.  Schmitt was working for Shoemaker, who encouraged him to apply for the Moon program.

*The proper term in Selenology, but that term is rather obscure and awkward.

The very next question is about Helium 3 – of great interest to this reporter – that almost certainly is to be found on the Moon.  This is a substance that does not occur naturally on Earth and could make Fusion power practical. Video should appear below:

Schmitt was about 82 at the time of this lecture and had not lost his quick wit and sense of humor – nor his pitching arm (near the end).

Uber Alley – The Artyard

February 22, 2021

A lot of Houston passes me on my random-walk car journeys around the City and the surrounding lands.  The new phone has refused to allow me to transfer photos off of it as a USB device with another drive letter – like the previous phone did so handily.  So, I resort to a ridiculous method of sending emailed attachments to myself on the phone and receiving same on the computer.  It works.

I have passed this art storage area once and missed the chance to take photos.  I found it again and I know where it is now.    Probably they have security cameras, but I have decided not to publish its address because the place looks vulnerable.

The abstract conductor very much resembles an abstract cellist I have seen on public display near Jones Hall, I think.  The Charlie Chaplin – stretch version – seems to be about 20 feet tall.

 The many busts in this second photo resemble some similar art you might see off US 59 southbound .  I saw a block-sized green low-rise building near here, with bars on the painted-out windows, that was labeled as “Studios” – I don’t think they meant apartments. That may be associated with this place.  Are these works produced on speculation (and awaiting sales) or were they commissions that are not yet emplaced?  No idea.

Hasta Luego,


KBO 2014 MU69 – Post Conference

Foreword January 2021

   As a lifelong Astronomy Nerd (perhaps not at birth, but not long after) I cannot help but notice how Planetary Science has advanced over the last half century. To say that much has been discovered is a ridiculous understatement.  This theme of Solar System Astronomy can also be noticed in my other Categories (Comets, Planets, Asteroids, Urban Astronomy, Science and occasionally even in Going Walkabout, Energy, One Climate Fact and Humor*.

*These are the collections behind those icons on my homepage at Goingwalkabout.blog.

   This is the sequel to my earlier post Kuiper Belt Object 2014 MU69

   As related below the body now officially named  486958 Arrokoth was indeed described and analyzed at the 50th Lunar and Planetary Science Conference in 2019.

Prolog – March 2019

As expected, the LPSC has revealed much greater detail about the Kuiper Belt Object 2014 MU69 (A.K.A. Ultima Thule)

The flyby of this Kuiper Belt Object was declared a 100% success by the Principal Investigator Alan Stern.  The closest approach was at about one fourth the distance as the previous KBO encounter with Pluto.  This is not surprising when the new target is comparable to a small mountain on Pluto.  That, and the fact that the velocity of the probe is about seven miles per second (yes, per second) complicates the task.  Other compounding circumstances were the light level comparable to a moonlit night on Earth, a spacecraft design that does not allow continuous contact and a download rate that is agonizingly slow.  As discussed earlier these were design trade-offs that made a long, difficult exploration effort possible – and quite successful – on a limited budget.  

At the time of the Special Session at the LPSC, it had been 80 days since the encounter and considerable data had been received.  However, more than a year separates us from the completion of that transmission.  The state of knowledge at this time was summed up by the PI in the first presentation and those items are presented below along with details filled in by the presenters that followed.

Post-flyby Observations

An earlier comparison to a “snowman” shape were based only on a 2D view.  Both the bodies that makeup this contact binary are thinner in the third dimension.  The larger one (now popularly called “Ultima”) is actually shaped more like a thick hamburger patty.  The smaller body (Thule) is more nearly spherical, but still visibly “flattened”.  This is not unprecedented.  There is a moon orbiting Saturn called Hyperion that has a similar shape to Ultima’s. 

As promised, the resolution now available is greatly improved.  The panel below is a stereo “cross-eyed” view.  It takes a bit of practice, but it is possible to focus the left eye on the right image and vice-versa to get a clear and vivid 3-D view that appears between the two.  Sit up straight and view with no tilt on the image.  Hold your head very still and adjust by tilting slightly right or left.  It should resolve into a clear and quite impressive 3-D image.  I find it works best, with minimal eye-strain at about 2 feet (about 60 cm) away.

Figure 1: Raw images of the contact binary MU69.  These are from the LORRI instrument and therefore lack the red coloring or the previous, low resolution image.  Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute. 

Other observations:

  • The crater on the smaller body (Thule) is seen to be quite deep.  It may be an impact feature, but no one has dared to unambiguously claim so.  Other craters may have been caused by faulting, perhaps during the merger.  None of the few craters seen can definitely said to be caused by impact. 
  • A comparison was made to Phobos, the greater moon of Mars, and its biggest crater named Stickney.  The two bodies are roughly the same size. Phobos is one of the darkest objects in the inner solar system and in that sense, also very similar to Thule.  See Figure 2 for a side-by-side images. 

Figure 2:  Left: MU69-B (Thule) and Crater “Missouri” Right: Martian Moon Phobos and Stickney Crater 

Credit: NASA


  Phobos and the lesser moon of Mars, Deimos were discovered by American astronomer Asaph Hall in 1877.  Hall was about to abandon his search for Martian moons, but was convinced to struggle on by his wife, Professor Chloe Angeline Stickney Hall.  

Somewhere in the vast body of writings by Issac Azimov (and almost certainly somewhere in the shelves and piles of ancient paperbacks I still possess – and have forbidden my wife from recycling) is told the anecdote about a presentation wherein the speaker related this story and hoped – that when Phobos was ultimately imaged – a major feature might be named for the mathematician, suffragist and abolitionist who would not let Hall give up the search in which he ultimately succeeded. When the presenter (who may well have been Azimov, himself) admitted his ignorance of her name, an attendee stood up and shouted, “Angeline Stickney” (for she did not use her first name).  And, in the fullness of time, it came to pass that the crater that dominates the surface of Phobos is so named.

More Points about 2014MU69 / Ultima Thule

  • Bright spots tend to be in low zones.   Troughs and mounds are clearly discernable.
  • The merger of these two bodies into one was determined to be a “gentle one”.  In the distant realm of the Kuiper Belt, and especially among the “Cold Classical”, objects that find themselves near each other tend to be moving with the same velocities.  Willian McKinnon described this method of simulating the velocity of merger: “Walk into a wall”.
  • No satellites were detected.  Nor was there any detectable atmosphere.
  • This may be because any satellites there might have been would have been ejected from orbit during the “merger” process. 
  • It is my (your humble narrator) own  interpretation (2021) that this system once consisted of five or six main bodies – all orbiting in the same plane – that were slowly accumulated onto the larger of the two.  And then the accumulated “hamburger patty” (whose shape indicates the co-planar rotation IMHO) and the smaller body finally merged.  Tidal stresses in orbiting bodies tend to slow down the mutual rotation – thus bringing them all together.
  • The period of rotation has been pinned down to 15.9 hours. 

What’s Next?

The New Horizons spacecraft probably has enough fuel to re-direct to another Kuiper Belt Object.  There is not yet a target body known to be in reach and Ultima Thule was found at the limits of the Space Telescope capability.  It is expected that the probe’s own long-range imager (LORRI) will be the instrument to find the next destination.  It is estimated that one more target will be the last possible.  There is no hurry, however, since the probe will be in the Kuiper Belt until 2027 or so.

See NASA video about MU69/Arrokoth


Ex Sciencia, Trivia,