Tag: science

Astronomers more precisely estimate the diameter of neutron stars

10:53 am

Using several different techniques, astronomers now estimate that the typical neutron star will have a diameter of 11 kilometers, or about 7 miles.

What is significant about this new estimate is that if that neutron star happens to be orbiting a black hole and get pulled into it, it will be swallowed whole instead of being ripped apart.

Their results, which appeared in Nature Astronomy today, are more stringent by a factor of two than previous limits and show that a typical neutron star has a radius close to 11 kilometers. They also find that neutron stars merging with black holes are in most cases likely to be swallowed whole, unless the black hole is small and/or rapidly rotating. This means that while such mergers might be observable as gravitational-wave sources, they would be invisible in the electromagnetic spectrum.

In other words, such cataclysmic events would be largely invisible to observers.

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China completes remote communications test of Mars rover

9:07 am

The new colonial movement: Though the report today in China’s state-run press is remarkably vague and lacking in details, it appears that they have successfully completed a remote communications test between their planned Mars rover and their ground control center.

The report also said that this will be the “only” such test before the summer launch of their orbiter/lander/rover to Mars.

China has been exceedingly closed-mouthed about this Mars project. Except for one landing test (which I found far from impressive), they have provided very little information about their progress.
While this does not mean they are having problems, it also does not engender confidence, especially because the launch window is only about four months away.

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Martian badlands

12:54 pm

The Tyrrhena Terra badlands
Click for full image.

The photo to the right is a small section cropped from an image taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on January 2, 2020. It shows the rough, cratered southern highlands dubbed Tyrrhena Terra that lie between the low Isidis Basin to the north and Mars’ deepest basin, Hellas, to the south.

The image was taken not because any specific scientific request, but because MRO was doing spectroscopy over this area and it made sense to also take a photograph. Comparing the photograph with the spectroscopic data allows scientists to better understand that spectroscopy.

The white cross in the map below shows the location of this image. The map itself covers latitudes from 40 degrees north to 55 degrees south.
» Read more

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Earth’s day was half hour shorter 70 million years ago

9:37 am

Using data from an ancient fossil shell, scientists have determined that 70 million years ago the Earth’s day was about 30 minutes shorter, and that a year comprised 372 days.

This result is not a surprise, as scientists have known for a long time that the day has been growing longer as the Moon’s gravity, producing tides, wears away at the Earth’s rotation. This data however is the most precise yet, and will allow scientists to better constrain not only the Earth’s changing rotation over time but the Moon’s orbit. As it slows the Earth’s rotation its own orbit around the Earth gets longer, pushing it farther away.

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Curiosity reaches highest point yet on Mars

9:55 am

Curiosity looking north across Gale Crater
Click for full resolution version.

Time for some more cool images! The panorama above, cropped and reduced to post here, was assembled from images taken by Curiosity on March 6, 2020 by its left navigation camera, just after it topped the slope and settled on the very rocky plateau of what the scientists have dubbed the Greenheugh Piedmont, the highest point on Mars that Curiosity has so far traveled. It looks north, across Gale Crater to its far rim, about thirty miles away. That rim rises about a mile higher than where Curiosity sits today.

To quote Michelle Minitti, the planetary geologist who wrote the update describing this achievement:

Kudos to our rover drivers for making it up the steep, sandy slope below the “Greenheugh pediment” (visible in the [right] side of the above image) and delivering us to a stretch of geology we had our eyes on even before we landed in Gale crater!

The panorama below is also assembled from photos taken by the left navigation camera, but this time it looks south, across the piedmont toward Mt. Sharp. Its view of the the piedmont’s very very rough terrain I think proves that once the scientists have gathered their data from this point, the rover will descend back down and resume its original route, circling the piedmont to skirt its southern edge where orbital data suggests the going will be smoother.
» Read more

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Rolling boulders on Mars

12:01 pm

Boulder tracks on Mars
Click for full image.

Cool image time! The photo to the left, cropped to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on January 21, 2020, and shows several boulders at the bottom of a slope, along with the tracks those boulders made as they rolled downhill sometime in the far past.

Uphill is to the south. We know the dark spots at the end of these tracks are large boulders partly because of the wind streaks emanating away from them to the north. As the wind goes around each rock it produces eddies that produce the tracks. Based on the scale and the image resolution (about 10 inches per pixel), these boulders range in size from about one to five feet in diameter.

This image has two points of interest. First, the tracks left by the boulders seem to have a repeating pattern. My guess is that the pattern most likely formed because the boulders are not spherical in shape, and as they rolled each roll repeated a certain pattern reflecting that shape. This theory is reinforced by a close look at each boulder. Though the resolution is insufficient to resolve the boulders themselves, the pixel distribution for each strongly suggests an asymmetric shape.

Second, this image, when compared with an earlier MRO image of the same spot, taken fourteen years ago in December 2006, shows no obvious change. These tracks, and their boulders, have therefore probably sat here, as we see them, for a long time. Since there appear to be two sets of tracks, with one overlying the other, this suggests that two separate events (an earthquake or nearby impact) each time caused a bunch of boulders to break free and roll downward together, with the second set of boulder tracks crossing over the earlier set.

Establishing when those two events occurred, however, will require some on-site data, something that will likely not occur until humans roam the surface of Mars in large numbers.

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NASA dubs next Mars rover “Perseverance”

2:02 pm

NASA today announced that they have named their next Mars rover, due to launch in July, “Perseverance.”

The name was announced Thursday by Thomas Zurbuchen, associate administrator of the Science Mission Directorate, during a celebration at Lake Braddock Secondary School in Burke, Virginia. Zurbuchen was at the school to congratulate seventh grader Alexander Mather, who submitted the winning entry to the agency’s “Name the Rover” essay contest, which received 28,000 entries fromK-12 students from every U.S. state and territory.

“Alex’s entry captured the spirit of exploration,” said Zurbuchen. “Like every exploration mission before, our rover is going to face challenges, and it’s going to make amazing discoveries. It’s already surmounted many obstacles to get us to the point where we are today – processing for launch. Alex and his classmates are the Artemis Generation, and they’re going to be taking the next steps into space that lead to Mars. That inspiring work will always require perseverance. We can’t wait to see that nameplate on Mars.”

I truly hope that the rover is well-named, and lives a very long life on Mars, long enough that it is still in use the day an human arrives to touch it again.

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Coronavirus and the madness of crowds

1:45 pm

Yesterday I got a bit of frustrating and disappointing news. The 51st Lunar and Planetary Science Conference (LPSC-51) to be held in the Houston suburbs beginning on March 15 (to which I was planning to attend) had been canceled due to coronavirus/COVID-19 fears. From the organizers’ email:

We regret to inform you that LPSC 51 will be cancelled due to concerns about COVID-19. This difficult decision has been made after a careful assessment of the risks as determined by the CDC and WHO; consultation with NASA PSD leadership; and consideration of community feedback. We are fully committed to ensuring that our conference attendees remain safe and well.

The organizers had earlier in the week sent out an email stating that they were considering their options because of the epidemic, and would announce a decision on March 6. That they pushed forward the cancellation decision by two days was almost certainly prompted by the revelation yesterday that a case of coronavirus had been confirmed in Houston.

To say this is a disappointment is an understatement. I was very much looking forward to meeting face-to-face many of the planetary scientists I have been corresponding with during the past few years. I was also eagerly anticipating getting an up-front look at the most recent discoveries in the exploration of the solar system, and to pass those discoveries on to my readers.

My disappointment however must pale in comparison to the disappointment of the scientists involved, especially the younger ones trying to establish themselves in the field. They need conferences like this to not only promote their work, but to network and to learn for themselves what others in their field are doing.

What makes this decision more appalling to me is how completely pointless and fear-driven it is. While it makes sense to try to slow the spread of the disease while scientists scramble to understand it and possibly develop a vaccine, it also makes no sense to stop living and to cease all effort out of mindless fear and ignorant panic.

And what we have today is the latter. This planetary conference was not the only one cancelled this week. On March 2 the American Physical Society panicked and cancelled its only annual convention, only 36 hours before it was about to begin, out of a fear that a gathering of 11,000 scientists from all over the world would help spread the disease.

This decision was absurd, however, as a large bulk of the conference’s attendees had already arrived. The cancellation thus accomplished practically nothing to stop coronavirus, while succeeding ably in stymying the spread of knowledge.

The simple fact is that though COVID-19 is a concern and must not be ignored, it is hardly the worldwide crisis being touted by our mindless press, odious politicians, and largely politically correct intellectual community.

A rational look at the facts give a bit of context that deflates the balloon of this madness. Several facts, both good and bad:
» Read more

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Japan suspends funding to TMT

9:33 am

The Japanese government has confirmed that it has suspended payment of its annual contribution to the budget of the Thirty Meter Telescope (TMT) because of the project’s inability to begin construction on Mauna Kea in Hawaii.

Japanese astronomers strongly prefer placing TMT on Mauna Kea because it is relatively close to Japan, unlike the proposed replacement site in the Grand Canary Islands in the Atlantic.

I would say this is the next nail in the coffin for TMT in Hawaii. The National Science Foundation (NSF) has money to fund construction of a big telescope for U.S. astronomers, but has not been able to decide on whether to give the money to TMT, or to the Giant Magellan Telescope (GMT), already under construction in Chile, or to both.

Astronomers have been lobbying for dual funding, using the argument that the two telescopes are in the opposite north and south hemispheres. Moving TMT to the Grand Canaries, at a higher latitude than Hawaii, strengthens this argument. With the apparent exit of Japan it could be that the way is now cleared to give up on Hawaii and for TMT to make the move to a more welcoming site.

Hawaii’s protesters, supported by the state’s Democratically-controlled government, will of course celebrate. What they will be celebrating however will be the death-knell of science in Hawaii.

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OSIRIS-REx makes closest reconnaissance of Bennu yet

9:07 am

The spacecraft OSIRIS-REx yesterday made its closest reconnaissance yet of the asteroid Bennu, sweeping past its primary touch-and-go landing site Nightingale by a distance of only 820 feet.

The main goal of yesterday’s low flyover was to collect high-resolution imagery of the site’s surface material. The spacecraft’s sample collection mechanism is designed to pick up small rocks less than 0.8 inches (2 cm) in size, and the PolyCam images from this low pass are very detailed, allowing the team to identify and locate rocks of this size. Several of the spacecraft’s other instruments also took observations of the Nightingale site during the flyover event, including the OSIRIS-REx Thermal Emissions Spectrometer (OTES), the OSIRIS-REx Visual and InfraRed Spectrometer (OVIRS), the OSIRIS-REx Laser Altimeter (OLA), and the MapCam color imager.

After completing the flyover, the spacecraft returned to orbit – but for the first time, OSIRIS-REx reversed the direction of its safe-home orbit and is now circling Bennu clockwise (as viewed from the Sun). This shift in orbital direction positioned the spacecraft for its next close encounter with the asteroid – its first rehearsal for the sample collection event.

The touch-and-go sample grab is targeted to take place in August.

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Protein molecules found in meteorite

9:00 am

Scientists have discovered bits of a protein molecule inside a meteorite that fell in Algeria in 1990 and was quickly recovered.

The protein is called hemolithin.

For hemolithin to have formed naturally in the configuration found would require glycine to form first, perhaps on the surface of grains of space dust. After that, heat by way of molecular clouds might have induced units of glycine to begin linking into polymer chains, which at some point, could evolve into fully formed proteins. The researchers note that the atom groupings on the tips of the protein form an iron oxide that has been seen in prior research to absorb photons—a means of splitting water into oxygen and hydrogen, thereby producing an energy source that would also be necessary for the development of life.

The real significance of this find is what it reveals we do not know. Most asteroid material from the very beginnings of the solar system (the type of material that would contain such a protein) is very fragile, and does not survive the journey though the Earth’s atmosphere. Thus, our meteorite sample obtained here on Earth, which is our entire sample, is very biased.

When we start getting samples back from asteroids (as both Hayabusa-2 and OSIRIS-REx are about to do), our understanding of the early solar system, as well as that of asteroids, will change radically. This story only gives us a hint of that fact.

Hat tip reader and fellow caver John Harman.

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Birth of a planetary nebula

8:49 am

Beginnings of a planetary nebula

Astronomers, using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile have created a multi-spectral radio image of a dying star in its very initial stages of becoming a beautiful planetary nebula.

[Using ALMA,] the team obtained a very detailed view of the space around W43A. “The most notable structures are its small bipolar jets,” says Tafoya, the lead author of the research paper published by the Astrophysical Journal Letters. The team found that the velocity of the jets is as high as 175 km per second, which is much higher than previous estimations. Based on this speed and the size of the jets, the team calculated the age of the jets to be less than a human life-span.

“Considering the youth of the jets compared to the overall lifetime of a star, it is safe to say we are witnessing the ‘exact moment’ that the jets have just started to push through the surrounding gas,” explains Tafoya. “The jets carve through the surrounding material in as little as 60 years. A person could watch their progress throughout their lifetime.”

Over time those jets, thought to be caused by the interaction of the central star with a smaller secondary star that orbits it, will interact increasingly with the surrounding gas. The result will be a quite spectacular planetary nebula.

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Mars rover Update: March 4, 2020

1:25 pm

Panorama looking south and uphill
Click for full resolution.

Curiosity

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

Map of Curiosity's travels

Since my last rover update on January 13, 2020, Curiosity has finally moved on from the base of Western butte, where it spent more than a month drilling a hole and gathering a great deal of geological data. Rather than head downhill and around the plateau and back to its planned route (as indicated by the red line in the map to the right), the Curiosity science team decided to push upward and onto the Greenheugh Piedmont (as indicated by the yellow line).

They had always planned to reach the top of this plateau, but not for several years. First they were going to head east to study a recurring slope lineae (see my October 2019 update), an example of a dark streak that darkens and fades seasonally and could provide evidence of water seepage from below ground.

Instead, they decided the close proximity of the top of the piedmont and its geology was too tempting. The piedmont is apparently made up of a layer that is very structurally weak, and breaks up easily, as you can see by the panorama above. It also appears to sit on softer, more easily eroded material, which thus accentuates this break up. If you look at the left part of the panorama you can see what I mean. The piedmont layer there is the thin unbroken layer sitting on what looks like sand. As that sand erodes away the layer quickly breaks into small pieces, as shown in the rest of panorama.

Traveling on the piedmont will likely be difficult and threaten Curiosity’s wheels. I suspect this reality prompted them to choose to get to the top and obtain data now, rather than wait several more years of rough travel that might have made access to the piedmont difficult if not impossible.

They presently sit just below the top, and are studying their options before making that last push.
» Read more

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Jupiter in glorious color

9:21 am

Jupiter in glorious color
Click for full image.

Cool image time! The photograph on the right, reduced to post here, was color enhanced by citizen scientist Emma Walimaki from the original Juno image in order to bring out the features and storms visible in the upper storm layers of Jupiter.

The photo was taken during Juno’s 25th close fly-by of the gas giant, and thus we are only seeing a small portion of Jupiter’s sphere.

In comparing this image with the original, it appears that Walimaki simply made the colors that were already there brighter and more distinctive. Thus, these colors represent real data. Jupiter’s cloud tops are really blue, orange, tan, and brown, unlike Earth’s consistently and boringly white water clouds.

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Summer at the Martian North Pole

1:20 pm

Buzzell pedestal crater in context with polar icecap scarp
Cool image time! The image above, cropped, reduced, and brighten-enhanced to post here, was taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) on December 26, 2019 of the dunes just below the 1,500 to 3,000 foot high scarp that marks the edge of the Martian north polar icecap. I have brought up the brightness of the dune area to bring out the details.

This one image shows a range a very active features at the Martian north pole. At this scarp scientists have routinely photographed avalanches every Martian spring, as they have been occurring, caused by the warmth of sunlight hitting this cliff wall and causing large sections to break off. As Shane Byrne of the Lunar and Planetary Lab University of Arizona explained in my September 2019 article,

On Mars half of the images we take in the right season contain an avalanche. There’s one image that has four avalanches going off simultaneously at different parts of the scarp. There must be hundreds to thousands of these events each day.

Buzzell dunes, March 19, 2019
Click for full image.

On the left side of the image is an area of dunes that Candice Hansen of the Planetary Science Institute in Arizona has dubbed “Buzzell.” As spring arrives here, she has MRO regularly take images of this site (as well as about a dozen others) to monitor the changes that occur with the arrival of sunlight on the vast dune seas that surround that polar icecap.

The image to the right zooms in on one particular distinct feature, a pedestal crater, surrounded by dunes, that I have labeled on the image above. This image was taken just as spring began, with the Sun only five degrees above the horizon. At that time the dunes and pedestal crater were mantled by a frozen layer of translucent carbon dioxide that had fallen as dry ice snow during the sunless winter and then sublimates away each Martian summer.

Since March I have periodically posted updates to monitor the disappearance of that CO2 layer. (See for example the posts on August 2019 and November 2019.) Below are two more images, showing the ongoing changes to this area from early to late summer.
» Read more

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ExoMars2020 parachute tests delayed until late March

8:59 am

The European Space Agency (ESA) has decided to delay until late March the next high altitude tests of the revamped ExoMars2020 parachutes, despite the success of recent ground tests.

The tests of the 15-meter-diameter supersonic and 35-meter-wide subsonic parachutes—an essential part of the entry, descent and landing phase of the mission—had been scheduled for December and February. The delay comes despite six ground tests demonstrating successful parachute extraction – the point at which damage was caused in earlier, failed high altitude tests.

Both tests need to be successful for the go-ahead for launch of 300-kilogram Rosalind Franklin rover during the July 25 to Aug. 13 Mars launch window. Any failure would mean a wait of 26 months for the next launch window, opening late 2022.

There will be a meeting next week of the project’s top management, from both Russia and Europe, and I strongly suspect that they are going to decide to delay launch to the 2022 launch window. Not only have the parachutes not been tested successfully at high altitude, they recently discovered an issue with the glue holding the solar panel hinges on the ExoMars Rosalind Franklin rover.

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OSIRIS-REx bypasses laser altimeter issue

1:40 pm

The science team for OSIRIS-REx has figured out a bypass for the failure of one of the spacecraft’s laser altimeters, originally used during close flyovers of the surface of the rubble-pile asteroid Bennu.

The mission has made the decision to use OLA’s High Energy Laser Transmitter (HELT) to provide the ranging data to focus PolyCam during the Mar. 3 flyover of site Nightingale. OLA consists of two laser subsystems, the HELT and the Low-Energy Laser Transmitter (LELT). OLA’s LELT was originally scheduled to provide these data, however, as a result of the anomaly that occurred during the Recon B site Osprey flyover, the team has determined that the LELT system is no longer operable. Despite the LELT’s condition, the HELT system has continued to operate as expected, and will be used to focus PolyCam for the remaining reconnaissance passes.

According to Erin Morton, head of communications for OSIRIS-REx in the Principal Investigator’s Office, the failure of LELT will not impact the touch-and-go sample grab, presently scheduled for sometime in August.

We don’t need OLA [either the low or high energy transmitters] for the sample collection event. OLA’s main purpose was to collect the altimetry data needed to make topographical maps for the sample site decision. It successfully accomplished that last year – which means that the instrument has completed all of its primary mission requirements. OLA isn’t used for navigation.

Instead, they are using an autonomous system that compares previous high resolution images with images taken during descent. In addition, they have a lidar system available as well.

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Glacial breakup on Mars

12:15 pm

glacial breakup on Mars
Click for full image.

Cool image time! The photograph to the right, cropped and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on December 22, 2019 and was titled “Contact Between Debris Apron and Upper Plains in Deuteronilus Mensae”.

The section of the full image that I have focused on shows what appears to be the downhill break-up of the surface debris covering an underlying water ice glacier. The grade is downhill to the south.

I am confident that this is buried glacial material based on recent research:

Both of these reports found lots of evidence of shallow ice in Deuteronilus Mensae, a region of chaos terrain in the transition zone between the Martian northern lowlands and the southern highlands.

With this image we see what appears to be the slippage of that ice downslope, causing breakage and cracks on the surface, with much of that surface made up of the dust and debris that covers the ice and protects it. Towards the bottom of the image it even appears that the disappearing ice is unveiling the existence of a bunch of buried bedrock mesas, typical of chaos terrain, previously hidden by the ice because it filled the surrounding canyons.

Below is a close-up of the photograph’s most interesting area of break-up.
» Read more

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Falcon Heavy wins launch contract for NASA’s Psyche asteroid mission

11:57 pm

Capitalism in space: NASA today awarded the launch contract for its Psyche asteroid mission, set to launch in July 2022, to SpaceX’s Falcon Heavy rocket.

The total bid price was $117 million, which according to the release includes “the launch service and other mission related costs.” Though this is higher than the normal price SpaceX charges for a Falcon Heavy launch ($100 million), it is far lower than the typical price of a ULA launch. Furthermore, Falcon Heavy has more power, so it can get the spacecraft to the asteroid faster.

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