Tag: science

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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Peering into a Martian pit

1:44 pm

Peering into a pit
Click for full image.

Cool image time! The science team for the high resolution camera on Mars Reconnaissance Orbiter last week released the above image of a pit to the west of the giant volcanoes Arsia and Pavonis Mons. The left image is without any adjustments in exposure. The right image has brightened the pit’s interior to bring out details in order to see what’s there. As planetary scientist Ross Beyer of Ames Research Center noted in his caption:

The floor of the pit appears to be smooth sand and slopes down to the southeast. The hope was to determine if this was an isolated pit, or if it was a skylight into a tunnel, much like skylights in the lava tubes of Hawai’i. We can’t obviously see any tunnels in the visible walls, but they could be in the other walls that aren’t visible.

Wider view of pit
Click for full image.

Because the image has been rotated 180 degrees, north is down. The northern wall of the pit appears to be either very vertical, or overhung. A tunnel might head north from here, but because of the angle of the photograph, this cannot be confirmed.

To the right is a wider look from the full photograph, showing the surrounding terrain, with north now to the top. In line with this pit is a depression that crosses the east-west canyon to the north. This alignment strongly suggests that a fault or fissure exists here, and that an underground void along this fissure line could exist. It also suggests that a deeper and larger void could exist below that larger canyon.

This pit, and the accompanying fissures, were likely caused by crack-widening along these faults, produced as this volcanic region bulged upward.

Map of knowns pits surrounding Arsia Mons

This pit is also one of the many many pits found near these volcanoes. The map to the right shows by the black boxes all the pits documented by the high resolution camera on MRO in the past few years, with this new pit indicated by the white box.

Beginning in November 2018 until November 2019 I was almost doing a monthly post reporting the new pits photographed by MRO. Since November however the number of new pit images dropped. This is not because every pit has been imaged, but because it appears they have completed their initial survey.

Below is a list of all those previous pit posts:
» Read more

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Review of Kepler data uncovers seventeen more possible exoplanets

11:08 am

Worlds without end: In reviewing the entire Kepler database of 200,000 stars, scientists have found seventeen more candidate exoplanets, including one only 1.5 times the mass of the Earth that is also in the habitable zone.

From the paper’s abstract:

We present the results of an independent search of all ~200,000 stars observed over the four year Kepler mission (Q1–Q17) for multiplanet systems, using a three-transit minimum detection criterion to search orbital periods up to hundreds of days. We incorporate both automated and manual triage, and provide estimates of the completeness and reliability of our vetting pipeline. Our search returned 17 planet candidates (PCs) in addition to thousands of known Kepler Objects of Interest (KOIs), with a 98.8% recovery rate of already confirmed planets. We highlight the discovery of one candidate, KIC-7340288 b, that is both rocky (radius $\leqslant 1.6{R}_{\oplus }$) and in the Habitable Zone (insolation between 0.25 and 2.2 times the Earth’s insolation). Another candidate is an addition to the already known KOI-4509 system.

I must emphasize that these are candidate exoplanets, meaning their existence has not been confirmed by other observations, and could very well turn out to be false positives.

Still, that this independent review matched the previous list of Kepler candidates within 98.8% means that the list of exoplanet candidates from Kepler is solid and worth further study. With thousands of candidates, however, that further study is likely going to take a very long time. And the backlog will be growing significantly with the many thousands of additional exoplanet candidates expected to be found by TESS.

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First image of possible asteroid in orbit around the Earth

3:37 pm

asteroid orbiting the Earth?
Click for full image.

The Gemini telescope in Hawaii has produced the first image of what might be only the second asteroid ever discovered in orbit around the Earth.

The newly discovered orbiting object has been assigned the provisional designation 2020 CD3 by the International Astronomical Union’s Minor Planet Center. If it is natural in origin, such as an asteroid, then it is only the second known rocky satellite of the Earth ever discovered in space other than the Moon. The other body, discovered in 2006, has since been ejected out of Earth orbit. 2020 CD3 was discovered on the night of 15 February 2020 by Kacper Wierzchos and Teddy Pruyne at the Catalina Sky Survey operating out of the University of Arizona’s Lunar and Planetary Laboratory in Tucson, Arizona.

The photo to the right has been cropped to post here. The streaks are stars, since the telescope was tracking the asteroid in an attempt to cull the most resolution of it from the image.

This object is only a few yards across, and could very well be a piece of space junk from a mission launched many decades ago. It is also not in a stable orbit around the Earth, and is expected to be ejected from that orbit in April.

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The coming small satellite revolution

1:41 pm

Today I received a press release from the Universities Space Research Association (USRA), announcing a half-day symposium in Washington, D.C. on March 26, 2020 entitled ““The SmallSat Revolution: Doing More with Less.” The announcement was an invitation for the working press to register and attend, noting that the speakers will include, among others, Thomas Zurbuchen, NASA’s associate administrator science, Jeffrey Mamber, president of NanoRacks, and Patricia Cooper of SpaceX.

As interesting as this might sound at first glance, I will not attend. For one thing, it is on the other side of the continent, and I can’t afford to fly cross country for such a short meeting. For another, I don’t see the point. I attended a lot of these DC symposiums when I lived in Maryland, and though they were often very educational and the free food (paid for almost always by the taxpayer) was always enjoyable, I routinely found them somewhat lacking in newsworthy content.

Thirdly, and most important, yesterday I attended a much more newsworthy one day conference here in Tucson on exactly the same subject, dubbed the Arizona Academic CubeSat Symposium. Unlike the Washington event above — which will likely be a mostly superficial look at the burgeoning cubesat industry — yesterday’s symposium was focused on letting students and scientists describe actual and very ambitious cubesat projects presently under construction or design.

In less than seven hours I saw the following:
» Read more

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VIPER lunar rover delayed, NASA seeks new bids for delivering it to Moon

10:29 am

NASA earlier this week revealed that it is delaying the launch of its VIPER lunar rover until 2023, even as it announced that it is seeking new bids from commercial companies for delivering it to Moon.

In the past two months NASA has apparently been trying to reorganize its unmanned lunar exploration, resulting it a variety of puzzling and sometimes sudden shifts in policy and direction. First they announced they are going to issue a request for proposals, then they delayed it, then they issued it only to withdrew it one week later, with no explanation.

This week’s announcement is another attempt to release this request, accompanied by the delay in VIPER. Though NASA says the delay is to allow “for upgrades so that the rover can conduct longer and more exciting science on the Moon”, I think instead it is to simplify it so that the commercial companies will be able to launch and land it. VIPER’s heritage designs come from an earlier NASA rover project dubbed Resource Prospector that was cancelled because it was going to be too expensive and complex. I think the private companies building landers for such a rover told NASA that they couldn’t handle those heritage designs, forcing NASA to rethink.

If my suspicions are true, this is actually a very good sign. NASA is allowing the private sector to guide it in ways to save money and work more efficiently. That guidance might cause some initial delays as NASA shifts course, but in the long run it will make for a better run operation, costing less while accomplishing more.

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Chinese scientists publish radar results from Chang’e-4 lander

10:13 am

Layers as seen below ground by Chang'e-4 radar

The new colonial movement: Chinese scientists today published their first ground-penetrating radar results from their Chang’e-4 lander on the far side of the Moon.

Using a ground-penetrating radar instrument on Chang’e-4, researchers have found that the rover is likely sitting on different layers of ejecta—debris from multiple impacts over time that rained down at high velocities to blanket the lunar surface and now fill the crater. “[We] see a very clear sequence of [layers],” says Elena Pettinelli of Roma Tre University in Italy, one of the paper’s co-authors.

The rover’s radar instrument was able to penetrate up to 40 meters below the surface of the moon, more than twice the distance achieved by its predecessor, the Chang’e-3 mission, which landed on the lunar near side in December 2013. Data from the latest mission show three distinct layers beneath the rover: one made of lunar regolith, or soil, down to 12 meters; another made of a mix of smaller and larger rocks down to 24 meters; and a third with both coarse and fine materials extending the rest of the 40-meter depth.

The figure to the right comes from the paper [pdf] Though the layers have not been dated, their differences suggest different past events in the formation of this surface.

These results are excellent, but they also have many uncertainties. Radar can tell you a lot, but the only way you can really ever know anything about what’s below ground is to go there and actually do some digging.

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Enclosed Martian canyon, filled with ice

1:28 pm

Ice-filled canyon on Mars
Click for full image.

Cool image time! The photo on the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter on November 21, 2019. The uncaptioned image was simply entitled “Ice-filled Graben.”

The location is on the lower flanks of the giant volcano Alba Mons, which in itself sits north of Olympus Mons and the volcanic Tharsis Bulge. The canyon is called a graben because it was formed when a section of the crust slips downward along parallel faults. It does not have the features of a rill, or lava flow, as it starts and stops suddenly. It probably formed due to the rise of the volcano, pulling apart its flanks along faults, causing some sections then to slip downward.

How do the scientists know this is ice-filled? I suspect they have other data that indicates the presence of water, but there are also clear features inside this canyon that resemble the glacial features found elsewhere on Mars. For example, note the parallel lines near the canyon walls. These indicate past surface levels as well as layers within the ice from cyclic climate processes. The line of pits along the southwest wall, where the surface gets more sunlight, also suggests that this sunlight is causing more ice to sublimate away.

Finally, the graben is located at 46 degrees north latitude, definitely far enough north for such ice to exist, based on ample other research.

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Confirmed: Betelguese is brightening, as predicted

1:58 pm

More observations have now confirmed that Betelguese is once again brightening, as predicted.

Photometry secured over the last ~2 weeks shows that Betelgeuse has stopped its large decline of delta-V of ~1.0 mag relative to September 2019. The star reached a mean light minimum of = 1.614 +/- 0.008 mag during 07-13 February 2020. This is approximately 424+/-4 days after the last (shallower: V ~ +0.9 mag) light minimum was observed in mid-December 2018. Thus the present fading episode is consistent with the continuation of the persistent 420-430 day period present in prior photometry.

In other words, the star’s dimming, though deeper than earlier dips, was right in line with a well-known variation cycle. While absolutely worth close observation and study, the data now strongly suggests that this is relatively normal behavior for this aging red giant star. It will likely go supernova sometime in the future, not likely now.

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Quakes by InSight indicate Mars’ interior is active

1:01 pm

Cerberus Fossae

The first seismic results from InSight’s seismometer now show that the interior of Mars is active, with regular moderately-sized quakes.

The Seismic Experiment for Interior Structure (SEIS) instrument – a seismometer developed by an international consortium under the leadership of the French space agency CNES – recorded a total of 174 seismic events between February and September 2019. Twenty of these marsquakes had a magnitude of between three and four. Quakes of this intensity correspond to weak seismic activity of the kind that occurs repeatedly on Earth in the middle of continental plates, for example in Germany on the southern edge of the Swabian Jura hills.

Although only one measurement station is available, models of wave propagation in the Martian soil have been used to determine the probable source of two of these quakes. It is located in the Cerberus Fossae region, a young volcanic area approximately 1700 kilometres east of the landing site.

Cerberus Fossae is a land of cracks and linear depressions located between the giant volcanoes, Elysium Mons to the north and Olympus Mons to the east. It is believed those fissures were caused by the rise of those volcanoes, stretching the crust and cracking it.

This new data from InSight strengthens this theory.

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New OSIRIS-REx close-up image of secondary asteroid landing site

9:40 am

Osprey landing site on Bennu
Click for full image.

The OSIRIS-REx science team today released one of the images taken during the spacecraft’s recent close reconnaissance of its secondary touch-and-go landing site on the asteroid Bennu.

I have cropped their oblique image to focus, in full resolution, on that landing site, dubbed Osprey, which is the crater on the left side of the photo. The boulder in that crater “is 17 ft (5.2 m) long, which is about the length of a box truck.”

After the fly-by, the science team had announced that the spacecraft’s laser altimeter had failed to operate, and the images taken by its highest resolution camera (not the camera that took today’s image) “are likely out of focus.”

Based on this image, what look like tiny pebbles inside the crater are actually boulders ranging in size from mere inches to as much as five feet across. If their high resolution images are soft, it will thus be hard to map out the terrain sufficiently to safely make a touch-and-go landing here.

More important, there is still no word on whether they have fixed the laser altimeter. Without it I suspect a landing will be very difficult, if not impossible.

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Engineers to use InSight’s scoop to help digging process

7:38 pm

Insight’s engineers, having failed to get its mole pile driver to dig down as planned, now plan to use the lander’s scoop to push on the mole in the hope this will prevent it from popping up with each hammer drive.

[T]he mole is a 16-inch-long (40-centimeter-long) spike equipped with an internal hammering mechanism. While burrowing into the soil, it is designed to drag with it a ribbonlike tether that extends from the spacecraft. Temperature sensors are embedded along the tether to measure heat coming deep from within the planet’s interior.

…The team has avoided pushing on the back cap [at the top of the mole] until now to avoid any potential damage to the tether.

It appears to me that they are running out of options. This new attempt carries risks. It could damage the tether required to obtain underground temperature readings, the prime purpose of the experiment. However, if they don’t get the tether into the ground, this will also prevent the experiment from functioning. Thus, this attempt could essentially be a Hail Mary pass, gambling all on one last all-or-nothing gambit.

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Ice-filled canyon on Mars?

9:00 am

The ice-filled head of Mamers Valles
Click for full image.

The image to the right, rotated, cropped and reduced to post here, was taken on December 19, 2019 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled “Head of Mamers Valles”, it shows the very end of one side canyon to this very extensive canyon system made up of the fractured fissures and mesas of chaos terrain.

Mamers Valles itself sits in the transition zone between the northern lowland plains and the southern cratered highlands. This specific canyon is close to those lowlands, at a latitude of 40 degrees north, where scientists believe there are many buried inactive glaciers of ice.

The image reinforces this belief. The entire canyon appears practically filled with what looks like ice. In fact, it almost looks like we are looking down at a frozen lake with a layer of snow on top of it. In this case, the layer is not snow, but dust and dirt and debris that covers the ice to protect it and prevent it from sublimating away.

The overview map below shows the location of this canyon, by the red cross, within Mamers Valles.

Mamers Valles

Mamers Valles is actually a very large collection of miscellaneous canyons, flowing into the lowlands. In some areas it looks like very old chaos terrain, with the canyons so eroded that all we see are scattered mesas. In other places the canyons more resemble meandering river canyons sometimes interspersed with crater impacts.

Scientists have analyzed the canyons in Mamers Valles, and from this concluded that they were likely formed from “subsurface hydrologic activity”. which in plain English means that flowing water below ground washed out large underground passages, which eventually grew large enough for their ceilings to collapse and form the canyons we see today.

Yesterday I posted an image of a string of pits that could very well be evidence of this same process in its early stages of canyon formation. In Mamers Valles the process is far more advanced, and the canyons have existed for a long time, long enough for the planet’s inclination to go through several cycles of change, from a low of 25 degrees tilt (what it is now) to has high as 60 degrees. At that high inclination the mid-latitudes were colder than the poles, so that ice would sublimate from the poles to fall as snow in the mid-latitudes, forming active glaciers within canyons such as this.

Now that the planet’s inclination is similar to Earth’s, 25 degrees, the poles are slightly colder than the mid-latitudes, and the glaciers in this canyon are either inactive (if buried) or slowly sublimating away so that the water can return to the poles.

Here however the surface debris appears to be protecting the glaciers, leaving the canyon filled mostly with ice. For future settlers this ice would likely be relatively accessible, and at a latitude where the environment is also relatively mild, for Mars.

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Yutu-2 finds rocks that appear young

7:29 am

Yutu-2 has found a cluster of small rocks that appear relatively young, with little erosion.

The rocks also also appear as if they came from another place on the Moon.

Closer inspection of the rocks by the rover team revealed little erosion, which on the moon is caused by micrometeorites and the huge changes in temperature across long lunar days and nights. That anomaly suggests that the fragments are relatively young. Over time, rocks tend to erode into soils.

The relative brightness of the rocks also indicated they may have originated in an area very different to the one Yutu-2 is exploring.

Youth in this case is very relative. The rocks might be young when compared to the surface on which they sit, but they still could be more than a billion years olf.

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Astronomers photograph baby stars in Orion

9:17 am

Some of the baby stars surveyed
Click for full image.

Astronomers using two radio telescopes have created multi-wavelength radio images of 300 protoplanetary disks, or proplyds, found in the star forming region in the constellation Orion. The image to the right shows only a small sampling of the proplyds imaged.

“This survey revealed the average mass and size of these very young protoplanetary disks,” said John Tobin of the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and leader of the survey team. “We can now compare them to older disks that have been studied intensively with [the radio telescope] ALMA as well.”

What Tobin and his team found, is that very young disks can be similar in size, but are on average much more massive than older disks. “When a star grows, it eats away more and more material from the disk. This means that younger disks have a lot more raw material from which planets could form. Possibly bigger planets already start to form around very young stars.”

Of the disks photographed, four appear to be extremely young, probably less than ten thousand years, because of their very blobby and irregular shape.

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Martian wind-swept buried depressions

1:57 pm

Wind-swept Martian depressions
Click for full image.

Cool image time! The photo to the right, rotated, cropped and reduced to post here, was taken on January 3, 2020 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows three strange teardrop-shaped depressions, clearly wind-swept and partly buried by dust and sand.

The location on Mars of these depressions is in the transition zone between the southern cratered highlands and the northern lowlands. This is also a region dubbed the Medusae Fossae Formation, a region where it appears a great deal of volcanic material was laid down during one or more eruptive events 3 to 3.8 billion years ago.

Whether these depressions were formed during those events is impossible to tell from the available data, especially because the underlying bedrock is buried in dust.

Their shape appears to have been caused as the wind slowly exposed three buried peaks of hard rock. The wind, blowing from the southwest to the northeast, would hit the peaks, producing an downward eddy that would churn out dust from the windward side. The wind and dust would then blow around the peaks, creating the teardrop tail on the leeward side to the northeast.

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Juno’s first measurement of water content on Jupiter

3:40 pm

The uncertainty of science: Scientists today released their first measurements from Juno of the amount of water found in Jupiter’s atmosphere.

The Juno science team used data collected during Juno’s first eight science flybys of Jupiter to generate the findings. They initially concentrated on the equatorial region because the atmosphere there appears more well-mixed, even at depth, than in other regions. From its orbital perch, the radiometer was able to collect data from a far greater depth into Jupiter’s atmosphere than the Galileo probe – 93 miles (150 kilometers), where the pressure reaches about 480 psi (33 bar).

“We found the water in the equator to be greater than what the Galileo probe measured,” said Cheng Li, a Juno scientist at the University of California, Berkeley. “Because the equatorial region is very unique at Jupiter, we need to compare these results with how much water is in other regions.”

These results remain very preliminary, especially because they have not yet gathered data at higher latitudes. Regardless the amount so far detected, 0.25% of all molecules in Jupiter’s atmosphere. seems remarkably small, suggesting that Jupiter has relatively little hydrogen or oxygen in its atmosphere.

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China’s candidate landing site on Mars

12:19 pm

One candidate landing site for China's first Mars lander/rover
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The image to the right, reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and provides a close-up of the relative smooth terrain found in the region on Mars that the Chinese have said is one of their prime landing sites for their 2020 Mars rover and lander. According to planetary scientist Alfred McEwen of the Lunar & Planetary Laboratory in Arizona,

There was a presentation at the European planetary & science conference in Geneva last fall, and a Chinese scientist gave an update on their plans and showed this area with the lat-long coordinates. That’s what I’m going on.

McEwen also admits that “there might have been a change since then. I’m not in the loop.” No one outside China really is, as that government remains quite opaque on these matters. They will likely only reveal their final landing site choice as we get closer to launch.

Overview

This location, on the northern lowlands plains of Utopia Planitia, makes great sense however for a first attempt by anyone to soft land on Mars. In fact, in 1976 these plains were the same location that NASA chose for Viking 2, for the same reasons. (The Viking 2 landing site was to the northeast of the Chinese site, just beyond the right edge of the overview map) While there are plenty of craters and rough features, compared to most of Mars’s surface, Utopia could be considered as smooth as a bowling ball.

Even so, a look at the full image shows that there are numerous features nearby that would be a threat for any robotic lander. McEwen notes,
» Read more

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Images reveal changes in Betelgeuse’s shape as it has been dimming

10:16 am

Betelgeuse dimmed
Click for full image.

Using the Very Large Telescope in Chile astronomers have produced before and after images of the red giant Betelgeuse, showing the changes to the star in the past year as it has dimmed by about 36%.

The image to the right, cropped and reduced to post here, was taken in December and shows the star in its dimmed state. Below the fold is a short video that compares this image with a photograph taken in January 2019. The star was then more spherical and evenly bright.

Betelgeuse’s misshaped profile and uneven brightness is not actually a new thing. See for example this 2017 image, where I noted that the bulge on the star’s side suggested “that continuous observations would reveal the outer atmosphere waxing and waning almost like the stuff inside a lava lamp.” The star is a giant gasbag that in the past has frequently been observed with dark patches on its surface and a sense that it is not always spherical. Those changes however have not occurred with such a significant dimming, a full magnitude

In late December I had posted a story noting that the dimming appeared to be expected, caused by the alignment of two different regular fluctuations of brightness, one 5.9 years long and the other 0.5 year long. It was expected that the star would begin brightening again.

Right now astronomers estimate that the low point in these cycles will occur on approximately February 21st. If the star begins to brighten following that date it would confirm that this dimming is just part of its cycles. If not, then it could be that we are in the preliminaries to a supernova event that would probably make Betelgeuse bright enough to be seen during the day.
» Read more

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Anomaly during OSIRIS-REx flyover of secondary landing site

9:14 am

During its close fly-over of its secondary candidate touch-and-go landing site on the asteroid Bennu, OSIRIS-REx’s laser altimeter failed to work as planned.

On Feb. 11, NASA’s OSIRIS-REx spacecraft safely executed a 0.4-mile (620-m) flyover of the backup sample collection site Osprey as part of the mission’s Reconnaissance B phase activities. Preliminary telemetry, however, indicates that the OSIRIS-REx Laser Altimeter (OLA) did not operate as expected during the 11-hour event. The OLA instrument was scheduled to provide ranging data to the spacecraft’s PolyCam imager, which would allow the camera to focus while imaging the area around the sample collection site. Consequently, the PolyCam images from the flyover are likely out of focus.

They are analyzing their data to figure out what went wrong and whether it can be fixed. The press release implies that this loss will not impact the touch-and-go at the primary landing site, but does not say so directly. Without the laser altimeter I wonder, how they will know their exact distance as they approach?

Then again, they have not yet downloaded the full dataset from the fly-over, so they might be able to get the instrument working again.

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Large glacier-filled crater/depression on Mars?

12:31 pm

Glacier-filled depression?
Click for full image.

Cool image time! The photograph on the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on December 21, 2019. It shows the eastern half of the floor and interior rim of a large squarish-shaped crater or depression in what seems to be an unnamed region of chaos terrain located in the transition zone between the Martian southern highlands and the northern lowland plains.

The floor of this depression has many of the features that indicate the presence of a buried ice glacier, including flow features on the depression floor, linear parallel grooves, and repeating moraine features at the slope base. In fact, all these features give the strong impression that this crater is ice-filled, to an unknown depth.

Chaos terrain, a jumble of mesas cut by straight canyons, are generally found in this transition zone, and could be an erosion feature produced by the intermittent ocean that some believe once existed in the northern lowlands. Whether or not an ocean lapped against these mesas and created them, this chaos terrain is believed to have been caused by some form of erosion, either wind, water, or ice.

Wide context view

The location is of this chaos terrain in that transition zone is illustrated by the context map to the right. It sits on the edge of the vast Utopia Basin, one of the largest and deepest northern lowland plains. It also sits several hundred miles due north of the planned landing site of the Mars2020 rover in Jezero Crater. There is a lot of chaos terrain in this region, with lots of evidence of buried glaciers flowing off the sides of mesas.

Today’s image, with its numerous features suggesting the presence of a buried glacier filling the depression, reinforces this evidence.

Closer context view, showing the chaos terrain region

What impresses me most about this particular depression — should it be ice-filled — is its size. I estimate from the scale of the image that the depression is about six miles across, somewhat comparable though slightly smaller than the width of the Grand Canyon. And yet, unlike the Canyon it appears to have a wide flat floor across its entire width. The second context map to the right zooms in on this chaos region to show how relatively large the depression is. It would not be hard to spot it from orbit. We don’t know the depth, but even if relatively shallow this depression still holds a heck of a lot of water ice.

While the depression appears like a crater in lower resolution wider photographs, higher resolution images suggest it is not round but squarish. Why is not clear, and unfortunately MRO’s high resolution camera has taken no other images of it. This image was also one of their terrain sample photographs, taken not because of any specific research request, but because they need to use the camera regularly to maintain its temperature. This location, having few previous images, fit this schedule and made sense photographing.

Thus, no one appears to be specifically studying this location, making it a ripe subject for some postdoc student who wants to put their name on some Martian geology.

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A baffling repeating fast radio burst

1:36 pm

Astronomers are baffled by a fast radio burst, a phenomenon that is a mystery in its own right, that also repeats its bursts in what appears to be a regular pattern.

Researchers looking at data from the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB) first spotted this FRB, known as FRB 180916.J0158+65, in 2019. In January 2020, they published a paper in the journal Nature that reanalyzed old data and found more than one burst from FRB 180916.J0158+65. They traced this FRB back to a relatively nearby spiral galaxy. What’s new in this latest paper, published Feb. 3 to the arXiv database, is the regular pattern in the bursts. The FRB, they found, goes through four-day cycles of regular activity, bleating out radio waves into space on an almost hourly basis. Then it goes into a 12-day period of silence. Sometimes the source seems to skip its usual four-day awake periods, or lets out only a single burst. CHIME/FRB is able to watch the FRB only some of the time, they noted, so it’s likely the detector misses many FRBs during the awake period.

At present they have no idea what is causing the pattern, other than a realization that it defies all the theories for explaining the previously discovered fast radio bursts.

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NASA breaks ground on new communications antenna

1:28 pm

NASA has broken ground on the construction of the first new communications antenna since 2003 at its Goldstone, Californa, site, one of three the agency maintains worldwide for communicating with its planetary probes.

There has been a desperate need to both expand and upgrade this network, dubbed the Deep Space Network, for years, a need that will grow even more desperate next year with the addition of two more rovers on Mars.

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The range for exposed ice scarps on Mars keeps growing

9:20 am

Overview of ice scarp locations on Mars

In January 2018 scientists announced the discovery of eight cliffs with visible exposed ice layers in the high mid-latitudes of Mars. At the time, those eight ice scarps were limited to a single crater in the northern hemisphere (Milankovic Crater) and a strip of land in the southern highlands at around latitude 55 degrees south.

In the past two years scientists have been using the high resolution camera on Mars Reconnaissance Orbiter (MRO) to monitor these scarps for changes. So far they have seen none, likely because the changes are below the resolution of the camera.

They have also been able to find more scarps in the southern hemisphere strip beyond that strip at 55 degrees south.

Now they have found more scarps in the northern hemisphere as well, and these are outside Milankovic Crater. As in the south, the new scarps are still all along a latitude strip at about 55 degrees.

The map above shows with the black dots the newer scarps located in the past two years. The scarp to the east of Milankovic Crater is typical of all the other scarps, a steep, pole-facing cliff that seems to be retreating away from the pole..

The scarp to the west of Milankovic Crater is striking in that it is actually a cluster of scarps, all inside a crater in the northern lowland plains. Moreover, these scarps are more indistinct, making them more difficult to identify. According to Colin Dundas of the U.S. Geological Survey’s Astrogeology Science Center in Arizona,
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