Physics – Page 2 – Stone Fig

Moon Bowl

In 1990 Science News printed an article which told of the Mimbres culture of what is now southwest New Mexico. The Mimbres people made black-on-white pottery adorned with intricate designs and mysterious animal. Of particular note in the article was a shallow bowl with the figure of a rabbit painted on the inside. According to the article the rabbit is an animal associated with the moon in numerous indigenous cultures of what is now the Southwest United States and Central America.

Upon close observation, the image of a rabbit on its hind legs can be seen in the dark areas of the full moon. Which might have led to the link between the rabbit and the moon.

The article concerned a study led by astronomer R. Robert Robbins and student Russell R Westmoreland then of the University of Texas in Austin. In studying the pottery of the Mimbres culture, they happened upon a specific bowl which pictured a rabbit “clutching” a small circular image with 23 rays. They proposed that this bowl was a record of the explosion of the supernova which created the Crab Nebula. The explosion was recorded by Chinese astronomers in the 11^th century Common Era (CE). This would make the bowl, now known as the Supernova bowl, the only known record of the supernova that created the Crab Nebula outside China and Japan.

At the time I found the story intriguing and started a search for more information on stories from indigenous peoples related to a rabbit on the moon. I was also curious about the shape of the shallow bowl. It was round but quite shallow and would not be able to hold much inside, whether it was water, or grain, or sand. I was not able to find much information on either, but I was also wrapped up in my work as an engineer – and camping along the unpopulated portions of the Outer Banks of North Carolina.

Several decades later I was sitting on my screen porch at night. I might not have been in the wilderness, but I was outside enjoying a very pleasant evening. The light that entered the porch was from a single streetlight across the street. I happened to look up at several items we had hanging on the wall of the porch, one of which was a large, shallow bowl I had bought in street market in Morocco in the 1960s. We had two of these bowls hanging on the wall as they are well made and have a colorful geometric pattern. As the light from the streetlight hit the bowls at a shallow angle the side of the bowl cast a shadow across the curved depth of the bowl and created a pattern of a waxing crescent moon, as it proceeded to a full moon. I was amazed. I carefully removed the bowl from the wall and turned it so that the light of the streetlight hit it a different angles and created a shadowing affect that appeared like the changing phases of the moon.

I found this interesting and wondered how ancient people explained the phases of the moon, or whether they might have thought of the moon as a bowl. Of course, we now know that the moon is not a bowl but rather is a sphere created around the same time as the Earth. As both revolved around the Sun and each other they became more and more rounded from the effect of the rotating motion.

Several years later while looking for a space-related gift for a colleague who was retiring, I came across a “moon bowl”. It was made of metal with an acid-etched surface. It was very shallow and looked very much, in its general shape, like the Mimbres bowl I had read about so many years before. I gave the gift and told the story, or what I thought was a plausible story, of how ancient people might have used a bowl to explain the phases of the moon.

Recently, I went in search of more of these metal bowls but was disappointed to learn that the foundry in Vermont was no longer making the bowls.

But the story does not change, and now when I stand outside and look up at the night sky. I wonder what ancient people thought the moon and the stars and the wandering planets might be. Some stories have come down to us, from when those people, our ancestors, stood outside and gazed up and the night sky and marveled at its beauty.

The Science News article from 1990 may be found at; https://www.sciencenews.org/archive/astronomy-71

Dr. R. Robert Robbins remains on the staff of the University of Texas in Austin where he teaches the history and philosophy of astronomy and archaeoastronomy; and science education.

The picture of the “Supernova Bowl” below is from a copy of the Science News article. I will post a better one if I can find it.

Four-Points

WOW! I am still excited, even two weeks after my wonder-filled find.

I was out in the open fields and forest edges on a warm Saturday, hiking and enjoying being outside. As I crossed a field, I saw something sticking up out of the grass ahead of me. It was about 50 yards away. The sunlight highlighted it so it stood out from the surrounding grasses even though it was not much higher that the brown stalks.

The area where I do most of my local hiking has a rather large white-tailed deer population. There are several herds that populate the area with numerous males of all ages.

One of the aspects of the white-tail deer, which every school child knows, is the male’s antlers are shed each year in the late Spring. Each year, each male deer will grow a new set of antlers. The antlers grow through the Spring and Summer, reaching their full size at beginning of the deer’s mating season known as “the rut”. As the male deer grows older his antlers grow larger with each passing year. A young male may only grow antlers that come to a single point. These are also known as spikes.

An older male will grow more massive antlers with numerous points. The antlers remain on the male until after the mating season is over. At that time the male deer’s body chemistry begins to change which signals his body that the antlers are no longer needed. His antlers become less firmly attached to his skull, and they prepare to fall off. This physiological change takes place in the late Winter and early Spring.

The antlers may fall off as the buck is walking through the woods where the antlers may be brushed off by low branches. They may fall off due to a jolt, if the deer is involved in a late season battle with another male deer. They may fall off as the buck runs and jumps across a field.

In the part of Virginia where I hike this change and the shedding of antlers generally happens after mid-February. If you are out in the woods and fields where deer roam and browse, you may find a single antler, or in some cases a pair of antlers. Finding a pair is rather rare, as the antlers fall off at different times. The pair may be far apart across a field or patch of woods. Sometimes though they fall off on a used trail, so that even if they are shed on different days they may be found at locations on the same trail. It’s a random pattern depending on where the deer goes, his body chemistry, and whether there is an event that causes the antlers to be knocked or brushed off his head.

Then the forest or field takes over. These “sheds” are not just useless bone. Small forest creatures will gnaw on the antlers as they are a source of phosphorous and calcium and other minerals for these creatures. These may be mice emerging from their winter tunnels, or foxes and coyotes.

And of course, there are people who may pick them up. These people, like me, enjoy walking across the fields and up through the woods looking for whatever they might see and enjoying the peace of the natural surroundings.

I have found small sheds before, but this find was certainly different with its polished four points. When I picked it up, I was surprised by how heavy it was. It weighed about four pounds. I have been out to the area where I found it twice more to see if its mate will turn up. It has not. It might not have fallen off yet. Or it has fallen off and some forest creature, or another walker, has carried it off.

Betelgeuse – Fading

So just what is going on with Betelgeuse?

That’s a good question, and no one seems to have the answer. It may not be possible to have an answer right now.

First of all Betelgeuse is one of my favorite stars in one of my favorite constellations. Betelgeuse is a red super giant star in the constellation Orion. For basic comparison Betelgeuse is 600 times the diameter of the sun and emits 7,500 times the amount of radiation as the Sun. If Betelgeuse were in the Sun’s position the red giant would engulf the planets of the solar system out beyond the orbit of Jupiter.

In the Winter, Orion is clearly visible at night in the northern hemisphere. Betelgeuse is the bright reddish start at the upper end of Orion on the observers left. That is considered the right shoulder of Orion. Just as when you are facing a person, your left side is opposite their right side.

We have all likely been able to see Orion at some time in our lives and are familiar with its shape. A visual aspect of the major stars is shown in the diagram above. There are many more stars in the constellation, but it is these stars that are easiest to pick out when looking up at the constellation at night. Betelgeuse is the star on the upper left. The brightest star in the constellation is Rigel which is opposite Betelgeuse in the lower right side. The other two stars that make up the “frame” of the body of Orion are Bellatrix and Saiph, in the, respectively, upper right position and the lower left position of these four stars.

But discussing the constellation cannot be done without expressing the beauty of the true jewel of Orion, the Orion nebula, the middle star in Orion’s sword that hangs from the three stars of his belt.

Recently there have been numerous articles about the dimming of Betelgeuse. Betelgeuse is a variable star known to dim and brighten over a period of time. However the current dimming is greater than those seen previously. In an article in EarthSky, there is a pair of photographs of Betelgeuse take by Brian Ottum in February 2016 and in December 2019. By comparing the two photographs, the dimming of the star can easily be seen. I found that scaling the picture down in size actually made the difference more apparent.

But can I see this in the sky?

Yes, relatively speaking. Relatively from having seen the star in previous winters as it crossed the sky. Whether out star-gazing on darkened fields, or going out well before sunrise to listen for owls or other birds, I will sit quietly in my folding chair and stare up at the sky. That’s a grand way to spend some time. From this I have a picture in my mind’s eye of the stars in Orion. To me the four stars could be separated as the diagonal pair of Betelgeuse and Rigel, and a second diagonal pair of Bellatrix and Saiph. The stars in these parings have always seemed similar in brightness to me. If you look the stars up you will of course find that the apparent brightness or the absolute magnitude of the two stars in the pairing are not close, but the pairing is the two brighter stars and a second paring of the two less bright stars. To me the diagonal pair of Betelgeuse and Rigel have always been somewhat matched in brightness in the night sky.

After I had seen several articles related to the dimming of Betelgeuse I went out and looked up to see Orion on several nights. But I did not have a picture of what I remembered seeing. I had to recall in my mind how the stars shone. And I could see a difference in Betelgeuse. It was still reddish but it was considerably less bright.

So why the dimming of this inconstant star. Again a good questions and the answer to which will only truly be revealed by the passage of time. Several articles speculated on the shrinking of the giant star as it prepares to blow off its outer shell and explode in a super nova. But I will not need to sit out each night and watch for this as an event like that might not happen for 100,000 years or more. But maybe I will sit out next week and keep my eye on it. That would be a spectacular sight.

However, the light from Betelgeuse takes a over 650 years to reach earth. So, it might have happened already and the light of the event has not yet reached earth.

And recently gravity waves were observed by the Laser Interferometer Gravitational-Wave Observatory (LIGO) that came from the area of the sky in the general area of Betelgeuse. What is that about? In reading information from the American Association of Variable Star Observers (AAVSO) again we do not know the source, but it does not appear to emanate from Betelgeuse.

So we wait to learn. But in the meantime, we can go out on any Winter night and enjoy looking up at the stars of Orion. His frame shines out as does his belt and his sword. The constellation dominates the Winter sky. A bonus are his dogs represented by Sirius and Procyon. And if the night is dark and the sky is clear, below them hiding in the grass you may see Lepus, the rabbit.

The EarthSky article may be found at: https://earthsky.org/space/ligo-gravitational-wave-burst-near-betelgeus

A “tweet” from Dr. Stella Kafka, Director and CEO of AAVSO, on January 14, 2020, may be found by searching at: https://twitter.com

Beetles in the Fog

Happy Thanksgiving to all my readers.

I can only imagine that it is a curious sight. The first curious image is fog rolling onto and across a desert. A second, desert beetles facing into whatever breeze might be pushing the fog, with their beetle heads down and their beetle rears lifted upward so the fog, water laden, is pushed along its back.

These curious beetles are the Namib Desert Beetle (Stenocara gracilip) which face the breeze from the ocean and expose the wing-cases along their backs to the incoming fog and collect water from the fog that is condensed on its wing cases. Then due to the beetle’s curious posture the water droplets flow downward to the beetle’s mouth.

In the arid Namib desert on the south west coast of Africa, plants and animals must find a means to get water to survive. This is also true of many people around the world. Using methods similar to those of the beetle, devices have been constructed so some people in arid regions can harvest water from the moisture in fog. A project in Morocco has been under development since 2005. The project won a United Nations Climate Change award for the supplying villages with water from new water taps and supply line, and also for alleviating the burden on women who had to spend hours a day in drawing and hauling water from wells to supply their homes. Similar projects have been used in other arid locales that are close to an ocean.

More recently two papers were given at the 72nd Annual Meeting of the APS Division of Fluid Dynamics in Seattle Washington which took place earlier this month (November 2019). One was on the capability of gathering water characteristics of a single wire in a study related to the collection capabilities of designed projects. The other paper was based on a study conducted by Hunter King, of the University of Akron in Ohio, and colleagues which investigated how the Namib Desert Beetle collects water along its back. The abstracts of these two papers may be found at http://meetings.aps.org/Meeting/DFD19/Session/Q25.7 and http://meetings.aps.org/Meeting/DFD19/Session/Q30.1, respectively.

For the beetle the study shows how microscopic ridges, bumps and pits along the beetle’s hard wing case allow it to achieve an improved rate of water collection from the fog. The study included the development of 3D printed spheres with manufactured ridges, bumps, and pits of different configuration for testing in a wind tunnel. These test showed that the microscopic texture of the surface influences the behavior of the collected water droplets. In the case of the beetle these differences in the roughness and smoothness of the surface of the hard shell wing-case on the beetle’s back influenced the movement of the water droplets to the beetle’s mouth. The beetle is able to gather and consume water to enhance its survival in the arid desert. And it must be a wondrous sight to see.

It is through the investigation of different technologies that we, the people, will be able to find solutions to alleviate thirst, hunger, and illness around the world.

We, the fortunate few who have the most, should express or thanks always for what we have. We should also seek out ways to help our brothers and sisters who do not have the resources that we so often take for granted.

Art work above is a modification of picture borrowed from http://morawatersystems.com/biomimicry-the-namib-desert-beetle-a-source-of-inspiration/

Other articles include: https://www.dailymail.co.uk/sciencetech/article-3949572/The-fog-catchers-Sahara-make-water-AIR-hundreds-people.html ; https://www.moroccoworldnews.com/2016/09/197525/moroccan-fog-water-harvesting-project-wins-united-nations-award/ ; https://www.wired.com/2012/11/namib-beetle-bottle/ ; https://www.bbc.com/news/technology-20465982

UPDate – The Event – Transit of Mercury 2019

Yesterday, 11 November, 2019, Veterans Day, Mercury made its fourth (2003, 2006, 2016, 2019) transit of the Solar disk in the 21^st century. I was glad to be able to view the event on my solar projection device. It’s homemade and has brought me many hours of enjoyment being out in the fields of Virginia trying to catch a glimpse of the solar events of both Mercury and Venus. In the pictures below you will see short pieces of tape with dates written on them. These dates represent my attempts over the last fifteen years to view transits of the two inner planets. In 2004 and then again in 2012 I tried to view the transits of Venus. In 2004 the initial stages of the event were obscured by a heavy fog. However, I was able to capture a glimpse of the event just before its conclusion. Yesterday, I was able to watch a great deal of the transit of Mercury.

My viewing platform is built around a Newtonian telescope that I bought from Sears in 1986 to view the last passing of Halley’s Comet. The platform is two hinged boards. The bottom board is a base for mounting the viewing platform on a hand truck, the upper board holds the telescope and the viewing screen. The viewing screen is mounted over the eye piece of the telescope. The screen is a piece of plastic sheet mounted on a wooden frame. I use a third piece of wood hinged to the upper board that enables me to maintain the proper elevation for the telescope. I also use wood blacks to help in holding the correct elevation, as the projection of the sun and the planet moves quickly across the screen.

The biggest surprise for me was how tiny the planet appeared on my screen. My screen was able to accommodate the disk of the sun. But in that projection Mercury appeared only slightly bigger than the period at the end of this sentence. Due to this as well as the texture of the viewing screen and my questionable skill as a photographer, I was not able to take a picture of the “dot” of Mercury that I can provide in this article. However, I present my pictures of the event and my viewing platform.

I am happy to share the experience and my excitement at seeing that small dot proceed across the disk of the Sun.

My original post leading up to the transit of Mercury was posted on October 30, 2019.

Transit of Mercury – Get Ready!

The Transit of Mercury will take place in the early morning of November 11, 2019. Now is the time tor prepare.

There is a shelf in my garage above the cabinets.. Its way up there, and if I want to reach it I have to stretch, and maybe get a stick to push things so I can grab them.Up on the shelf are tools, and hard hats, and a rabbit box, plus equipment we made for old science fair experiments, and overlying it all is a contraption made of two pieces of plywood and numerous hinges. Lying on top of that is a spindly item with four threaded rods for legs that support a celluloid viewing screen.

This was my viewing platform for the transit of Venus in 2004; and then again for the transit of 2012. In 2012 it was cloudy where I was so I could not observe the sun – or Venus.

But the previous event in 2004 was the event for which I made the contraption. The contraption was built to hold my old Newtonian telescope. It was an inexpensive ($20.00) telescope but very functional. I have had the telescope for more than 30 years. I bought it in 1986 to view Halley’s comet. Since then I have used it often. In 2004 I planned to strap it into place on my T.V.P. (Transit Viewing Platform) and see what I could see. I made the T.V.P. so I could mount it on a hand cart for ease of movement. It had several elevation blocks to get the elevation that I needed, and I attached a small, hinged elevation board that gave me the ability to fine tune the elevation. Lastly I used a broad-headed “brad” (a nail made of wire) that helped me aim the device. I mounted the nail so it was pointed towards the sun. When the shadow of the nail head was centered on the base of the nail, I knew the telescope was pointed right at the sun.

A week before the transit I drove out to my viewing location in a local National Park. I needed to test my device. I am pleased to say it worked as planned. A ranger stopped and asked what I was doing and what the contraption was. I told him what I was doing, and assured him that the telescope and mount were not a rocket launcher. Although I must admit that it looked like one.

I was ready!

On the morning of the transit I got up early. When I looked out the window I was stunned. It was incredibly foggy. I have never seen fog so thick. But I was going! I was sure of my contraption, I was certain of my site with a good eastern exposure, and I hoped that the weather would break before Venus crossed the disk of the sun.

I was wrong.

As I drove out to the site I was unsure of what I would find. It was foggy, but I didn’t care, I was ready. The appointed time came, and the fog was no less thick. By the time of the transit being half completed the weather had not improved. I had to make a choice. I decided to go – and find a fog-free spot.

I put all my equipment back into my car and headed west. The road was covered with the fog, and I had to be careful in my driving. Finally, I made it out of the fog. I took a turnoff that I hoped would have a place to set up my telescope. I finally found one. I only had ten minutes before the transit was complete. I found a good spot. I took out the telescope and its T.V.P. and aimed it at the sun. There were still some clouds in the sky, but I had a good projection onto my screen. And there in the lower right was Venus! It was a small black dot against the disk of the sun. I stood in awe not of myself by of others who had chased this dot around the globe only to be disappointed by the weather. In 1761, the British expedition to Saint Helena, in the south Atlantic, did not see what I had just seen. They were explorers. I had followed in their footsteps.

On 11 November, 2019 Mercury will transit the sun. Venus makes its transits in pairs as in the 2004 and 2012 transits. There is a period of 105 to 122 years before another pair of Venus transits happen. Mercury has its transit more often. A transit of Mercury will occur 4 more times before 2060. So there are good opportunities to see it.

If you want to see the 11/11 transit you will need to find a place with a good eastern exposure. You must also have a projection device to see the small black dot on the face of the sun. Do not view the sun or the transit directly. Do not look at the sun. It will severely damage your eyes. Try to find a place that can help you observe the transit. And know that you are participating in an observation that has been important to scientists since they first were able to use telescopes and projection screens to observe it.

More information on the 11 November transit of Mercury may be found at https://www.jpl.nasa.gov/edu/events/2019/11/11/watch-the-transit-of-mercury-2019/

UPDate – Chang’e-4 slumbers

Its night time on the far side of the moon. On 11 July the China National Space Administration (CNSA) announced it had sent commands to its Chang’e-4 probe on the far side of the moon to go into its dormant state. The lander and the rover will both ‘sleep’ through the 14 day lunar night before they are sent commands to wake up and continue the mission. The lander and rover require sunlight to charge their electrical systems and so can only operate during the moon’s daytime. For the moon to completely rotate on its axis and the sunlight to return, takes approximately 29 days. The nighttime, when there is no sun, and the daytime, when the sun’s light reaches the surface of the far side of the moon, are both approximately 14.5 days. The progress of the lunar days across the surface of the moon can be easily seen from Earth in the changes phases of the moon.

However, as explained in the CNSA 11 July report, “As a result of the tidal locking effect [between the Earth and the Moon], the moon’s revolution cycle is the same as its rotation cycle, and the same side always faces Earth.”

This synchronicity has historically caused the far-side of the moon to remain unseen and a mystery (1). That is until the early days of humanity’s first tentative steps into space. In October 1959 a lunar probe, Luna 3, launched by the Soviet Union, sent back pictures of the far side of the moon. The first humans to see the far side of the moon were the American astronauts in Apollo 8 as they orbited the moon (10 times) in December 1968.

There is still a great deal to discover about the moon, both on the far side and on the side that faces the earth. The return of the sun, and the return of the Chang’e-4 probe to its mission, may enable further discoveries and help humanity to heighten the potential of humanity’s return to the moon – and to go beyond.

The pictures at the top include (upper) a picture from the current Chinese mission on the moon, and two pictures (lower) from Apollo 8.

The link to the Change-4 mission: http://www.cnsa.gov.cn/english/n6465719/c6806820/content.html

Apollo 8 mission: https://solarsystem.nasa.gov/missions/apollo-8/in-depth/

(1) Lil Wayne’s song “Dark Side of the Moon” – with Nicki Minaj – speaks to the mystery of the far side of the moon. – “On the dark side of the moon
I’ll be waiting, I’ll be waiting for you
On the dark side of the moon
And If you happen to get there before me
Leave a message in the dust just for me
If I don’t see it I’ll be waiting for you
On the dark side of the moon (yeah, yeah, yeah, yeah)” (Lyrics copied from https://www.azlyrics.com/lyrics/lilwayne/darksideofthemoon.html .)

UPDate – Mars Mole– Sol 213

The Mole is stuck, but there may not be anything touching it.

NASA and its partner Germany’s DLR are still trying to figure if they can get the inSight Mole unstuck. According to an article published by NASA on 5 July, the team now believes that the Mole has created a cavity so that there is no soil surrounding it. The Mole needs interaction (touching) the Martian soil in order to move forward/downwards. Without the surrounding soil the Mole cannot penetrate further.

The problematic void may be like a cavity formed under a “bridge” similar to a bridge/arch that can form in bulk carrier cargo vessels. Due to normal vibration during the voyage or in the unloading process, a bridge or an arch of the material being transported/unloaded can form across the material. The bridge/arch will not allow the material above it to fall into the cavity created by the unloading process. The bridge/arch may have been formed by the Mole in the Martian soil due to the vibration of the mole mechanism. These vibrations may have caused the material below the bridge/arch to collapse. The bridge/arch does not allow the Martian soil which the Mole has already penetrated to collapse into the cavity. If the material were able to collapse into the cavity perhaps the Mole could progress to is mission depth.

The pictures in this article show that NASA has moved the Mole mechanism from above the mole hole. The hole is indicated by the yellow arrow. The placement of the feet of the mechanism are shown by orange semi-circles. The tether that provides energy to the Mole and which allows data transmission up to the lander is shown by the curved green line. NASA will have to ensure that when it places the mechanism back over the hole that the tether is not crimped or broken.

In my original post on the inSight lander (4/4/2019 – Mars inSight H-P cubed) I asked whether it would be possible to remove the Mole and start at another location. The answer is no; the Mole cannot be extracted. There is no way to extract the Mole and then reload it into its mechanism so it could start again. And even if it did, would it only form another cavity and be in a similar situation?

Links to two articles on bridging are given below. The key to preventing bridging in earth-bound hoppers is control of material flow based on its cohesion and friction on the sides of the container. On Mars, well, it’s different. In the case were a bridge/arch forms, it is generally necessary to shock/vibrate the material so it will start to flow. In the case of the Mole, a shock might allow bridge arch to collapse filling the cavity with soil and the Mole may be able to move forward again.

Right now, according to current thinking, the Mole is probably dangling in this cavity. It needs material around it to move. Maybe if there was a nine-pound hammer on the lander it could give the area close to the hole a good whack. But that is not the case.

We all hope that the NASA/DLR team will be able to develop a means for the mole to move forward again.

The source information and the pictures for this article may be found at https://phys.org/news/2019-07-nasa-insight-mole.html .

Articles on bridging in hoppers on earth:

First Ever @ M87

There were people sitting on chairs on a stage. They were all introduced, including Dr. Shep Doeleman, the Director of the Event Horizon Telescope (EHT) project. There was applause, and then there was silence as everyone in the room sat up to listen closely and to see the picture they all hoped to see. The presentation was succinct, but everyone whether in the room or watching remotely from their offices or homes was waiting for the anticipated announcement. These included scientists, post-docs, students, managers, politician, reporters, and other interested people watching and listening. These other interested people were called the “black-hole enthusiasts”. The work was described, including the development of a Very Long Baseline Interferometer the size of the earth with multiple sites at locations around the globe. Not all of the sites were able to view the target location at the same time, but this supported obtaining good data since as the world turned other sites/telescopes were able to view the target location in space. High levels of collaborative processes were required for the EHT team to be successful.

The target was in galaxy M87, also known as Virgo-Alpha. It is the largest galaxy in the Virgo cluster. At the heart of the galaxy is a super-massive black hole. The international team was seeking to “image”, to create a picture, of the event horizon of the black hole in M87.

The room was quiet. Dr. Doeleman turned toward the screen and pressed the button on his control. For a moment there was total silence followed by the soft clicks of cameras in the room. Then applause. It did not carry on for wave after wave, but it was solid and positive and excited. The applause stopped as everyone in the room leaned forward to see the image. Everyone quieted down as if there were a sound to be heard. Every ear strained; every eye refused to blink.

The image on the screen clearly showed the edge of the event horizon inside of which not even light can escape. Dr. Doeleman stressed that it was the work of numerous nations, their agencies, and their early-career and senior scientists that made possible the development of the pictures. The pictures were created from more than 5-petabytes of information. It was the hard work of all these people that enabled the image seen today to be extracted from the mass of data.

Enthusiasts at home leaned closer to their computer screen and rose on the edge of their chairs. The room was full of virtual attendees who wanted to be part of this announcement of what is truly scientific history.

The picture showed (“north” being up in the picture) a glowing mass of light, the swirl of particles around the heart of galaxy M87 before they cascade across the event horizon into the darkness. The colors in the maelstrom indicated the speed of photon emissions from the accretion flow toward the event horizon. There was a distinct rise in color as the relative speed of the light flowing towards the observing telescopes in 1-mm wavelength increased on the south edge of the ring. And there in the center, the darkness of no light escaping, the back hole. And between the two the crisp edge of the event horizon.

The first-of-its-kind image and the science and math behind it and the cooperation behind it all, leads us to a transformation of our understanding of black holes.

Congratulations to the entire team and all those who supported and continue to support them.

The image of the black hole is based on the image provided by the NSF-EHT. The map of Virgo is based on a map provided by IAU and Sky and Telescope.

The announcement and press briefing can be viewed at https://www.nsf.gov/news/special_reports/blackholes/ .

Mars InSight H-P cubed

Tap. Tap. Tap.

Then – no further.

One of the dedicated science instruments on the Mars InSight lander has had to pause during its deployment. The instrument is officially known as the Heat Flow and Physical Properties Probe, which according to the Launch Press Kit is abbreviated HP3 (pronounced “H-P cubed”). Its mission is to take the temperature of Mars. It will determine the amount of heat that is escaping from the interior of the planet. Knowing this heat flow will help us better understand the evolution of the Martian interior – and the rate at which Mar’s internal core energy is diminishing.

The instrument includes a probe that is being hammered into the Martian soil to a depth between ten and sixteen feet (3 – 5 meters). But the probe, which is called the “Mole” by NASA, has met significant resistance at a much shallower depth. NASA is trying to determine if the resistance is coming from a rock or a gravel layer. Then they will need to decide how best to get beyond the obstacle. Can it be penetrated, or will another method be necessary?

As a gardener, or I should say as the shovel-man for a gardener, I know what it is to hit a resistive object while digging a hole. For me the resistance is often a stone of small to moderate size or perhaps a root of a nearby tree. Sometimes I can remove the impediment, but sometimes I must shift the location of the hole. Removing the impediment is not an option on Mars. There is no gardener on Mars that can kneel and sweep out the rubble with their gloved hand. *

The Mole is about 16 inches long and approximately an inch in circumference. The exterior of the Mole is aluminum. It is attached to a flexible tether that carries information to the instrument package that is attached to the deck of the lander. The hammer that provides the driving force is built into the Mole. There is no outside hammer at the surface level to drive the Mole into the soil. This means that there is no device, like the claw on the back of a hammer, that can extract the Mole so it can be placed in a different location.

Going back to my gardening efforts, I have often driven spikes for mats or pegs for garden borders into the ground. I have also driven steel rods to a depth or 18 to 24 inches to support a structure or a wall. In these cases, if I hit a rock or a root that I cannot penetrate I may be able to slightly reorient the item and try to slide past the obstacle. But that may not to be an option for the Mole on Mars. For clarity, I will have to ask NASA.

The Mole’s internal hammer was designed to enable the tip of the Mole to penetrate objects up to a certain hardness. This can be understood from the description of the operation in the mission Launch Press Kit which describes the process. The information in these documents states that it is expected that the hammer will be dropped between 5,000 and 20,000 times to penetrate the soil to its planned depth. The number of hammer blows required depends on the density and hardness of the soil matrix.

Currently the Mole has met an object of significant hardness. The hammer not only has to overcome the hardness of the material it has to penetrate, but it also has to overcome the friction of the sides of the Mole as it is driven through the obstacle plus the added friction of the flexible tether as it is dragged down the Mole’s hole.

NASA will determine the best course of action to allow the Mole to penetrate beyond its current depth. On March 21, the NASA Mission page stated that many ideas are being considered to free the Mole from the obstacle, and that the ideas will require “at least several more weeks of careful analysis.”

Stay tuned. Perhaps we will be able to slide past the obstacle and reach the appropriate depth.

Information for this article is taken form the NASA Mars InSight Launch Press Kit. The documents may be found at https://www.jpl.nasa.gov/news/press_kits/insight/ .

Picture based on NASA map in Launch Press Kit.

*I always wear gloves because there can be glass from an old bottle or a rusted nail dropped during construction.