Update on Chang’e-4 plant experiments

Link here. It appears the plant experiment has now run its course, designed as it was to end before the arrival of the first lunar night.

The experiment’s chief designer, Xie Gengxin of Chongqing University, told Xinhua that life inside the canister would not survive the lander’s first lunar night, which started on Sunday. The moon’s nighttime period lasts for about two Earth weeks.

It also appears that though the plant experiment included potato, cotton, and oilseed rape, only the cotton seeds spouted. China has only released a limited amount of information about this research, so to get further details we will likely have to wait for the published papers.

Seeds sprout on Chang’e-4

The new colonial movement: The cotten seeds in a plant experiment on Chang’e-4 have now sprouted, becoming the first biological life to grow on the Moon.

On Tuesday, Chinese state media said the cotton seeds had now grown buds. The ruling Communist Party’s official mouthpiece the People’s Daily tweeted an image of the sprouted seed, saying it marked “the completion of humankind’s first biological experiment on the Moon”.

Fred Watson, Australian Astronomical Observatory’s astronomer-at-large, told the BBC the development was “good news”. “It suggests that there might not be insurmountable problems for astronauts in future trying to grow their own crops on the moon in a controlled environment. …I think there’s certainly a great deal of interest in using the Moon as staging post, particularly for flights to Mars, because it’s relatively near the Earth,” Mr Watson said.

Prof Xie Gengxin, the experiment’s chief designer, was quoted as saying in the South China Morning Post: “We have given consideration to future survival in space. Learning about these plants’ growth in a low-gravity environment would allow us to lay the foundation for our future establishment of space base.” He said cotton could eventually be used for clothing while the potatoes could be a food source for astronauts and the rapeseed for oil.

This experiment is actually a very big deal, as it is the first biological experiment, ever, to take place in a low gravity environment. All previous plant experiments in space have taken place in zero gravity, and thus failed to tell us anything about growth in a partial Earth gravity environment.

That the seeds have sprouted only tells us that they can. What we don’t know yet is if the low lunar gravity distorts their growth.

Weird erosion in large Martian craters

Central pit in Asimov Crater

Cool image time! In reviewing the images in the December image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO, I came across the image to the right, cropped, rotated and reduced to post here, showing the western half of the central pit of Asimov Crater. (Click on the link for the entire photograph.) The eastern half can be seen here.

It is unusual to see central pits in craters. One instead expects to see central peaks. The pit itself is intriguing because of its sinkhole appearance. In both the northwest and southwest corners you can clearly see drainages flowing down into the pit, including recent faint darkened streaks indicative of past seep avalanches. The same can been seen for the pit’s eastern half. Along the pit’s western rim are parallel cracks suggesting that the plateau itself is slowly shifting downward into the pit.

Furthermore, the rim cliff has multiple drainage gullies, all beginning just below the initial top layers. The look of those cliffs is very similar to what sees on the walls of the Grand Canyon, where the top of the cliffs show layers with the bottom of the cliffs buried under a slope of alluvial fill, material that has fallen to slowly form those slopes. The drainage gullies however would have come later, and suggest that some form of seepage is coming out of the contact between the layers at the top of the slope.

A look at the context image below and to the right reveals the greater mystery of this crater, as well as nearby Maunder Crater, the subject of a recent captioned image release from Mars Odyssey.

context map showing Asimov and Maunder Craters

In both cases a circular interior gully separates the crater floor from the crater’s rim. In fact, the crater floor almost appears raised. This is especially striking with Asimov Crater, where the central floor appears like a very flat plateau, except for that central pit and the surrounding gully.

The MRO team has taken a lot of images of the gullies, which you can see if you zoom in to latitude -46.843° longitude 4.831° on the map image at this website. It is clear that they want to know more about the origins of this geology. It suggests water flow, even though these craters are located in the Martian southern highlands, a place that is more reminiscent of the Moon, with many ancient craters and far less evidence of significant change.

What the geology in these two craters suggest is that some erosion process is eating away at the crater floors, beginning at its edges as well where there are voids below that allow the surface to sink. While that erosion is certainly helped by wind, it also implies the presence of underground water, either as ice or liquid, in the past and even possibly today.

Ceres’ bright spots in Occator Crater

Occator Crater bright spot

Cool image time! The Dawn science team has released some additional images taken shortly before the mission’s conclusion when Dawn was in its closest orbit of the dwarf planet Ceres. On the right is a tiny cropped portion of a much larger mosaic of the bright spots on the floor of Occator Crater, focusing on one large bright spot that also includes a fissure cutting across it. If you click on the image you can see the entire mosaic, covering an additional four more bright areas.

The mosaic was taken in June 2018 from a distance of 21 miles.

The press release describes these bright areas as “deposits of salts, in particular sodium carbonate, possibly extruded through fractures connecting the surface to a deep reservoir of salty liquid.” That surely looks confirmed by the fissures in the image to the right.

Chandrayaan-2 launch now scheduled for mid-April

The new colonial movement: India’s Chandrayaan-2 lander/rover mission to the south pole region of the Moon has now been re-scheduled for mid-April.

The launch date had to be pushed from the initially scheduled January-February window, as a few related tests could not be completed by the Indian Space Research Organisation (Isro). Isro chairman K Sivan told the media on Friday that the next available slot is during March-April, and the launch could take place by mid-April. However, if this window is passed, the prestigious mission will have to be pushed again to June.

The article also suggests that they have made some changes to the mission’s flight plan.

Earth’s magnetic field undergoing unexpected changes

The uncertainty of science: For reasons that scientists do not understand, the Earth’s magnetic field has been undergoing unexpected shifts in the past two years, causing its north pole to move significantly and somewhat quickly from Canada across to Siberia.

Earth’s north magnetic pole has been skittering away from Canada and towards Siberia, driven by liquid iron sloshing within the planet’s core. The magnetic pole is moving so quickly that it has forced the world’s geomagnetism experts into a rare move.

On 15 January, they are set to update the World Magnetic Model, which describes the planet’s magnetic field and underlies all modern navigation, from the systems that steer ships at sea to Google Maps on smartphones.

The most recent version of the model came out in 2015 and was supposed to last until 2020 — but the magnetic field is changing so rapidly that researchers have to fix the model now. “The error is increasing all the time,” says Arnaud Chulliat, a geomagnetist at the University of Colorado Boulder and the National Oceanic and Atmospheric Administration’s (NOAA’s) National Centers for Environmental Information.

Note that they have delayed the release of the World Magnetic Model until January 30, claiming the delay is caused by the government shutdown. Seems bogus to me. As I have already noted, these scientists aren’t slaves. If they think this is so important, and they have completed their work (which the article suggests they have), they can release the model, regardless of the federal government’s funding.

Hat tip reader Stephen Taylor.

Lopsided ejecta from Martian crater

Crater with unequal ejecta

Cool image time! The image on the right, reduced and cropped to post here, comes from the December image release from the high resolution camera of Mars Reconnaissance Orbiter (MRO). (If you click on the image you can see the full resolution uncropped photograph.) Released without a caption, the release itself is intriguingly entitled, “Crater with Preferential Ejecta Distribution on Possible Glacial Unit.

The uneven distribution of ejecta material around the crater is obvious. For some reason, the ground was preferentially disturbed to the north by the impact. Moreover, the entire crater and its surrounding terrain look like the impact occurred in a place that was saturated somewhat with liquid, making the ground soft like mud.

That there might have been liquid or damp material here when this impact occurred is reinforced by the fact that this crater is located in the middle of Amazonis Planitia, one of the larger regions of Mars’ vast northern lowland plains, where there is evidence of the past existence of an intermittent ocean.

This however really does not answer the question of why most of the impact’s ejecta fell to the north of the crater. From the release title is appears the planetary geologists think that this uneven distribution occurred because the impact occurred on a glacier. As the ground has a lighter appearance just to the south of the crater, I suspect their reasoning is that this light ground was hard bedrock while the darker material to the north was that glacial unit where the ground was more easily disturbed.

This is a guess however (a common requirement by anyone trying to explain the strange features so often found on the Martian surface). Other theories are welcome of course, and could easily be correct as well.

Shutdown and government politics slows some science work

The partial government shutdown appears to be causing problems for some researchers, some of it fake and some of it real.

The article doesn’t put it that way. Instead, it sells the shutdown as a terrible tragedy, blocking all work by scientists, a claim that simply isn’t true if you read the article honestly.

The real problems include cases where the closure of government buildings prevents scientists from accessing their labs or research samples. The fake problems include things like this:

Rattlesnakes, bears, hurricanes, and freezing weather haven’t stopped ecologist Jeff Atkins from taking weekly hikes into Virginia’s Shenandoah National Park for the past 8 years to collect water samples from remote streams. But Atkins is now facing an insurmountable obstacle: the partial shutdown of the U.S. government, in its third week.

Park managers have barred Atkins from entering since 22 December 2018, when Congress and President Donald Trump failed to agree on a deal to fund about one-quarter of the federal government, including the National Park Service. That has shut down the sampling, part of a 40-year-old effort to monitor how the streams are recovering from the acid rain that poisoned them in past decades.

There is no reason this scientist can’t enter the park and get his samples. In fact, Trump administration policy has kept the national parks open, even if no one is working there. I am thus very suspicious of the claim that he is “barred” from entering.

Then there are claims that government scientists are forbidden from attending conferences. Bah. They aren’t slaves. If the conference is that important, they should go on their own dime. And if they aren’t willing to go, it makes me suspect their work is not that important. In fact, I know this, as I have watched many government scientists attend conferences merely to tout the wonderful things their government agency is accomplishing, not to really report on science.

The article also makes a big deal about the loss of pay to these individual scientists. My heart bleeds. For one thing, as government workers they are generally paid at a far higher rate, with many more benefits, than most taxpayers, who for the past decade have been suffering far worst economic times. These government scientists can afford the loss of pay for a few weeks.

For another, based on what has happened after all other previous shutdowns, Congress will approve their pay during this time, meaning this shutdown is really nothing more than an extra paid vacation for them.

I thus find myself having little sympathy for these scientists. In fact, the facts in this article make me inclined to think the taxpayer might benefit from getting rid of them all.

TESS spots first exoplanets plus supernovae and more

The Transiting Exoplanet Surveying Satellite (TESS) has successful spotted its first exoplanets.

NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets, or worlds beyond our solar system, in its first three months of observations.

The mission’s sensitive cameras also captured 100 short-lived changes — most of them likely stellar outbursts — in the same region of the sky. They include six supernova explosions whose brightening light was recorded by TESS even before the outbursts were discovered by ground-based telescopes.

These discoveries confirm that the spacecraft is operating exactly as designed. Now comes the herculean task of analyzing the gigantic amount of data it is pouring down to see what is hidden there.

Flowing cracked mud on Mars?

mud cracks in crater?

Cool image time! The image on the right, rotated, cropped, and reduced to post here, comes from the December image release of the high resolution camera of Mars Reconnaissance Orbiter (MRO. Uncaptioned, the release titles this image “Cracks in Crater Deposit in Acheron Fossae.” If you click on the image you can see the entire photograph at full resolution.

Clearly the cracks appear to be caused by a downward slumping to the north, almost like a glacier made of mud. We can also see places on the image’s right edge where the mud appears to have flowed off a north-south trending ridge, then flowed downhill to the north. All of this flow is away from the crater’s central peak, which is only partly seen in the photograph near the bottom. That section is the central peak’s southwestern end, with the whole peak a ridge curving to the northeast beyond the edge of the image.

At the north edge of this mud flow the cracks become wider canyons, as if long term erosion is slowing washing the mud away. The flow then stair steps downward in a series of parallel benches. Meanwhile, in the flat central area of the mud flow above can be seen oblong depressions suggesting sinks that also flow to the north.

crater context overview

You can get a better idea of the crater’s overall floor and central peak by the low resolution context image to the right. The white rectangular box indicates the area covered by the full image above. A close look at this part of the crater floor suggests to me a circular feature like a faint eroded smaller crater that includes as its eastern rim the larger crater’s central peak. This impression suggests that the flows seen in the full resolution image are heading downhill into the lowest point of this smaller crater, that upon impact had reshaped the larger crater’s floor.

This impression however is far from conclusive. The features in the large crater could simply be the random geology that often occurs in the floors of impact craters.

What makes this particular mud slide most interesting, as is usually the case for most Martian terrain, is its location.
» Read more

Sunspot update December 2018: Decline to solar minimum continues

Time for the monthly solar cycle update! NOAA today posted its monthly update of the solar cycle, covering sunspot activity for December 2018. As I do every month, I am posting it below, annotated to give it some context.

December 2018 sunspot activity

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

There really isn’t much to say about the sunspot activity in December. It continued to show a steady decline to solar minimum, exhibiting activity very comparable to what we saw in mid-2008 when the previous unusually long and extended solar minimum began.

One interested detail however: When NOAA issued this graph last month, it finally extended it out beyond the end of 2019 to the end of 2022. In doing so, it also extended out the 2009 prediction of the solar science community, as indicated by the red curve. I hadn’t commented on this last month, but if you look at that curve it drops to zero and then flatlines for the entire year of 2022.

If this is what the solar science community now expects for this upcoming minimum, it means that community is now expecting a record-breaking minimum, lasting far longer than any previous minimum, two to three years at least. It also means that they have not dismissed the possibility that the Sun is about to enter a Grand Minimum, where no significant sunspot activity is seen for literally decades.

Should such a grand minimum occur, it bodes ill for global warming advocates. The track record of the Earth’s climate consistently shows that when sunspot activity declines, the global climate gets colder. Why this happens is not clearly understood, though there is at least one theory backed up by good experimental data. Should this happen, we shall discover that global cooling is a far worse thing to fear than global warming.

Using LRO to find Chang’e-4

LRO image of Chang'e-4 landing area

The Lunar Reconnaissance Orbiter (LRO) science team has released a high resolution image from 2010 pinpointing the area on the floor of Von Kármán crater where Chang’e-4 landed. On the right is a reduced and partly annotated version.

They have not actually found the lander/rover, since this image was taken long ago before Chang’e-4 arrived. However, this image, combined with the Chang’e-4 landing approach image, tells us where the lander approximately landed. It also pinpoints where to look for it when LRO is next able to image this region, around the end of January.

By then, Yutu-2 will hopefully have traveled some distance from Chang’e-4, and LRO will be able to spot both on the surface.

Dust devil tracks on the Martian southern highlands

Dust devil tracks

Today’s cool image is cool because of how little is there. The image to the right, cropped to post here, was part of the December image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO). The uncaptioned release labeled this image simply as “Southern Intercrater Plains.” Located in the Martian southern highlands, this location is located almost due south of Arsia Mons, the southernmost in the chain of three giant volcanoes to the west of Marineris Valles (as indicated by the white dot on the overview image below).

If you click on the image you can see the entire photograph, though in this case it won’t show you much else than in the excerpt to the right. The terrain here appears flat. The only features of note are some small knobs and the random dark lines that are almost certainly accumulated dust devil tracks. There are also many dark spots, which might also be the shadows of even smaller knobs, but could also be instrument artifacts. I am not sure.

Location of dust devil image

The southern highlands are mostly cratered, with few signs that water ever flowed there. This image for example gives the impression of a vast lonely terrain that has changed little since the very earliest days of Mars’ history.

I expect that scientists could possibly assign some age to this terrain, merely by studying the dust devil tracks. If we calculate how often dust devils might traverse this place, and then count the tracks, assigning their order by faintness, with the faintest being the oldest, it could be possible to obtain a rough age of the oldest tracks.

Still, all that would do would tell us the approximate length of time in which a dust devil track can remain visible. And even if this is a long time, it doesn’t constrain the age of the surface very much, as the weather on Mars has certainly changed with time, especially because we think the atmosphere was once thicker.

What formed this flat terrain? My first guess would be a lava flow, caused when the numerous nearby craters were formed by impact. These craters were likely created during the great bombardment between 3 and 4 billion years ago, and while they have certainly been modified more than lunar craters because of the presence of an atmosphere on Mars, they are likely to have not changed much during that time. Similarly, this flat terrain is likely much like it was, several billion years ago. Dust devils have deposited dust and their tracks, but the hard bedrock remains as it was soon after it solidified.

“We have a snow-man!”

Ultima Thule, the snowman

The quote in the headline comes from Alan Stern, the principle scientist for New Horizons, during today’s press conference revealing the first high resolution images of Ultima Thule. The press release for this conference is now online. The image on the right is a reduced cropped version of the main release image today. If you click on it you can see the full resolution version.

The images reveal that Ultima Thule actually is two objects in contact with each other. In addition, the snowman description is apt, as it has a mottled appearance as if it was shaped roughly and somewhat gently over time. Tiny pebbles and rocks softly came together to form two snowballs that then eventually came to touch and join.

They describe this as the most primitive object ever observed. It is also dark, and red in color, like dark reddish dirt.

More images and data is still coming in, to be released in another press conference tomorrow.

First faint image of Ultima Thule

Ultima Thule, first image

In anticipation of receiving data from the fly-by just past midnight last night, the New Horizons team has released the image above, taken 24 hours earlier.

Just over 24 hours before its closest approach to Kuiper Belt object Ultima Thule, the New Horizons spacecraft has sent back the first images that begin to reveal Ultima’s shape. The original images have a pixel size of 6 miles (10 kilometers), not much smaller than Ultima’s estimated size of 20 miles (30 kilometers), so Ultima is only about 3 pixels across (left panel). However, image-sharpening techniques combining multiple images show that it is elongated, perhaps twice as long as it is wide (right panel). This shape roughly matches the outline of Ultima’s shadow that was seen in observations of the object passing in front of a star made from Argentina in 2017 and Senegal in 2018.

This object is definitely strangely shaped.

New Horizons is traveling fast, which is why we won’t get good images until practically the instant the fly-by happens. And the first downloads from that fly-by are due to arrive within the next two hours. Keep your fingers crossed that the spacecraft operated as programmed and captured Ultima Thule in all its weird glory.

One point about the sad state of journalism these days. Numerous media publications posted stories last night celebrating that fly-by, as if they knew it was a success. This is bunk. We won’t know what happened until this morning. To imply we do is the hallmark of fake news.

OSIRIS-REx moves into close orbit with Bennu

OSIRIS-REx has successfully completed an eight second engine burn to place it into a close orbit with the asteroid Bennu.

Now, the spacecraft will circle Bennu about a mile (1.75 kilometers) from its center, closer than any other spacecraft has come to its celestial object of study. (Previously the closest orbit of a planetary body was in May 2016, when the Rosetta spacecraft orbited about four miles (seven kilometers) from the center of the comet 67P/Churyumov-Gerasimenko.) The comfortable distance is necessary to keep the spacecraft locked to Bennu, which has a gravity force only 5-millionths as strong as Earth’s. The spacecraft is scheduled to orbit Bennu through mid-February at a leisurely 62 hours per orbit.

There is a bit of hype here. Other spacecraft have gotten far closer (NEAR, Hayabusa-1, Hayabusa-2) but then retreated for a variety of reasons. What makes this different is the plan to stay this close while they compile detailed data about Bennu’s surface in preparation for touchdown to grab a sample.

Juno images volcano plume on Io

Volcano plume on Io

Using several instruments, the Juno science team has successfully photographed an active volcano plume in Io’s polar regions. Two instruments measured the plume’s heat and radiation. Juno’s cameras meanwhile took the color image on the right. The bright spot on Io’s night side matches the location of the heat and radiation signatures from the other instruments.

JunoCam acquired the first images on Dec. 21 at 12:00, 12:15 and 12:20 coordinated universal time (UTC) before Io entered Jupiter’s shadow. The Images show the moon half-illuminated with a bright spot seen just beyond the terminator, the day-night boundary. “The ground is already in shadow, but the height of the plume allows it to reflect sunlight, much like the way mountaintops or clouds on the Earth continue to be lit after the sun has set,” explained Candice Hansen-Koharcheck, the JunoCam lead from the Planetary Science Institute.

This image is not the first time a spacecraft has caught an active volcanic plume on Io. In fact, practically the very first good images of Io during the Voyager 1 fly-by did this, confirming then that volcanoes are active on the Jupiter moon.

What this image further confirms however is how active Io really is. Volcanoes erupt there so continuously that it apparently isn’t that hard to catch one as it happens.

Engineers adjust Chang’e-4’s orbit

The new colonial movement: Engineers have adjusted Chang’e-4’s lunar orbit in preparation for landing.on the Moon’s far side.

The probe has entered an elliptical lunar orbit, with the perilune at about 15 km and the apolune at about 100 km, at 8:55 a.m. Beijing Time, said CNSA.

Since the Chang’e-4 entered the lunar orbit on Dec. 12, the ground control center in Beijing has trimmed the probe’s orbit twice and tested the communication link between the probe and the relay satellite Queqiao, or Magpie Bridge, which is operating in the halo orbit around the second Lagrangian (L2) point of the earth-moon system.

The space engineers also checked the imaging instruments and ranging detectors on the probe to prepare for the landing.

They need to time the landing so that it comes down in the Moon’s early morning. This will not only provide better visuals, with shadows to see surface details, but more importantly will give them 14 Earth days before sunset to get settled on the surface and initiate rover operations.

Why the Drake equation is overrated

The uncertainty of science: An astrophysicist explains why the Drake equation is useless for predicting the number of alien species in the universe.

While the Drake equation may have spurred the early scientific discussion of the search for extraterrestrial intelligence, it doesn’t have much value beyond that. We can’t use to it further our understanding, and we can’t use it to properly guide our thinking. The huge uncertainties in the parameters, the unknown ways those uncertainties mix, and the absolute lack of any guidance in even choosing those parameters robs it of any predictive power. Prediction is at the heart of science. Prediction is what makes an idea useful. And if an idea isn’t useful, why keep it around?

I just wish this same logic was applied to all climate models. They are as useless. Their own huge uncertainties have made them utterly unable to predict anything, for decades. Yet, despite this ongoing failure, vast amounts of research money continues to be poured into the cottage industry that produces them. Worse, too many people in both the intellectual and journalist communities take them far too seriously.

It is a tragedy that is hurting science badly.

Nancy Roman passes away at 93

R.I.P. Nancy Roman, NASA’s first chief astronomer, died on Christmas at the age of 93.

Her name is largely forgotten, but her support for building the Hubble Space Telescope in the 1960s and the 1970s was critical in getting it done. As important, her support for all in-space astronomy in these early years eventually made it possible. During her term NASA built and launched the first space telescopes. Some were duds. Some were incredible successes. Regardless, her leadership proved that astronomy in space made sense, leading to the achievements that have followed in the half century that has followed.

God speed, Nancy Roman.

Japan quits global whaling regulatory body

Japan yesterday announced that it is quitting the International Whaling Commission, a global whaling regulatory body founded shortly after World War II to regulate commercial whaling that has instead in recent years attempted to ban all commercial whaling, except for favored native tribes in Russia and the Arctic.

The article’s last few paragraphs provide the real political background to this move by Japan:

An IWC-Japan divorce is the culmination of a wide ideological divide at the commission between ardent anti-whaling nations and countries seeking recognition of limited commercial whaling activities as legitimate. The anti-whaling forces have the upper hand, even though IWC’s expansion has seen more pro-whaling countries joining in recent years.

At the Brazil gathering, Japan had attempted to nudge the IWC toward reforms that would have potentially paved the way for a resumption of commercial whaling. The IWC was initially established to regulate whaling but has enforced an outright moratorium on commercial whaling operations since the 1980s in a desperate bid to prevent the extinction of several whale species. Many whale species have since recovered to a degree, but a few are still considered endangered.

Japan’s reform push was easily voted down. Instead, a majority of IWC members voted to have the commission turn its back on commercial whaling for good. That successful resolution also condemned Japan’s scientific whaling practices, widely regarded as a clandestine commercial operation as Japan’s whaling fleet takes hundreds of whales each year, with the meat ending up in grocery stores and restaurants.

IWC also approved subsistence whale hunts for Arctic aboriginal communities.

The large Japanese delegation at Brazil didn’t hide its frustration. The government accuses IWC members of hypocrisy for allowing culture exemptions from the moratorium for Alaskan and Russian native groups, but not for Japan and Scandinavian whaling cultures.

In other words, this commission has become increasingly political. Rather than focusing on protecting whale populations while allowing whaling by all parties, it has decided to pick and choose who can whale, and has decided to ban Japan while giving others the right to whale.

This political bias is not much different than what was seen at the Paris climate accords. Those agreements put odious restrictions on U.S. commercial activity, while putting no restrictions on China and others. It was this political bias, totally divorced from any sincere effort to reduce CO2 emissions, that prompted Trump to exit that agreement.

Gale Crater dunes: dry and volcanic in origin

Using data from orbit and from the rover Curiosity, scientists have determined that the material in the dunes in Gale Crater that Curiosity has visited are very dry and volcanic in origin.

This dryness is in contrast with the underlying ground, which shows evidence of water. The data also suggests that the material either came from multiple volcanic sources producing different compositions, or some of the sand was somehow changed at a later time.

In other words, the sand in the dunes came from elsewhere.

Dried mud cracks on Mars?

Mud cracks on Mars?

Cool image time! The image to the right, cropped and rotated to post here, was one of the uncaptioned photographs in the December Mars Reconnaissance Orbiter (MRO) image release. If you click on the image you can see the entire photograph. I have cropped the most interesting area, though cracks can be seen in other areas in the image.

What we appear to have here is a darker lower valley filled with dried mud, which over time has cracked as it dried. At its edges there appear to be ripples, almost like one sees on the beach as waves wash the shore. The perimeter slopes even show darker streaks as if the water in some places lapped up the slopes, and in others flowed downward into the valley.

Later, several meteorite impacts occurred, the largest of which produced concentric dried cracks on its outside perimeter. This impact also provides a rough idea of the depth of the mud in this valley.

Mud of course suggests that this lower valley once was filled with water. Was it? It is not possible now to come to a firm conclusion, but this image’s location shown by the red dot in the overview map below and to the right, provides a clue that strengthens this hypothesis.
» Read more

OSIRIS-REx flies over Bennu’s north pole

Bennu's north pole

Cool movie time! OSIRIS-REx has completed its first planned fly-over of Bennu, this time above its north pole, and the science team has released a short movie showing part of that fly-over. I have embedded the movie below the fold.

This series of MapCam images was taken over the course of about four hours and 19 minutes on Dec. 4, 2018, as OSIRIS-REx made its first pass over Bennu’s north pole. The images were captured as the spacecraft was inbound toward Bennu, shortly before its closest approach of the asteroid’s pole. As the asteroid rotates and grows larger in the field of view, the range to the center of Bennu shrinks from about 7.1 to 5.8 miles (11.4 to 9.3 km).

They have four more fly-overs of the asteroid’s poles and equator as they assemble a detailed map of its surface.
» Read more

New asteroid radar images

near-Earth asteroid 2003 SD220

Cool radar images! The set of radar images above of near-Earth asteroid 2003 SD220 were created by combining radar data from three different radar telescopes on Earth, Arecibo in Puerto Rico, Green Bank in West Virginia, and Goldstone in California. As the press release notes:

The asteroid will fly safely past Earth on Saturday, Dec. 22, at a distance of about 1.8 million miles (2.9 million kilometers). This will be the asteroid’s closest approach in more than 400 years and the closest until 2070, when the asteroid will safely approach Earth slightly closer.

The radar images reveal an asteroid with a length of at least one mile (1.6 kilometers) and a shape similar to that of the exposed portion of a hippopotamus wading in a river.

The images have a resolution of 12 feet per pixel, so a close look should be able to reveal any large boulders, should they exist. Instead, I see a soft surface that to me resembles the surface of a sand dune, floating unattached to anything in space.

No rotational light curve from Ultima Thule?

Data from New Horizons as it is quickly approaching Ultima Thule has found that even though the object is expected to be oblong or even two objects it has shown absolutely no variation in light as it rotates.

Even though scientists determined in 2017 that the Kuiper Belt object isn’t shaped like a sphere – that it is probably elongated or maybe even two objects – they haven’t seen the repeated pulsations in brightness that they’d expect from a rotating object of that shape. The periodic variation in brightness during every rotation produces what scientists refer to as a light curve.

“It’s really a puzzle,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute. “I call this Ultima’s first puzzle – why does it have such a tiny light curve that we can’t even detect it? I expect the detailed flyby images coming soon to give us many more mysteries, but I did not expect this, and so soon.”

They have several theories, all implausible, to explain this. It could be they are looking at the object’s pole. Or maybe a dust cloud or numerous tumbling moons surround the object and hide the light variation.

Fortunately, we shall have an answer to this mystery in less than two weeks, when New Horizons zips past.

InSight installs seismometer on Martian surface

InSight has successfully placed its first instrument, its seismometer, on Martian surface.

They aren’t yet ready to start gathering data, however.

In the coming days, the InSight team will work on leveling the seismometer, which is sitting on ground that is tilted 2 to 3 degrees. The first seismometer science data should begin to flow back to Earth after the seismometer is in the right position.

But engineers and scientists at JPL, the French national space agency Centre National d’Études Spatiales (CNES) and other institutions affiliated with the SEIS team will need several additional weeks to make sure the returned data are as clear as possible. For one thing, they will check and possibly adjust the seismometer’s long, wire-lined tether to minimize noise that could travel along it to the seismometer. Then, in early January, engineers expect to command the robotic arm to place the Wind and Thermal Shield over the seismometer to stabilize the environment around the sensors.

They plan on deploying the heat probe (which will drill down about 16 feet) in January.

Curiosity’s future travels

MRO image of Curiosity's future travels

In the December release of images from the high resolution camera on Mars Reconnaissance Orbiter (MRO), there was one image entitled “Monitor Region Near Curiosity Rover.” To the right is a reduced, cropped, and rotated section of that image, annotated by me to show Curiosity’s future planned route (indicated by the yellow line). If you click on the image you can see the untouched full resolution version.

Curiosity’s journey has not yet brought it onto the terrain shown in this image. (For the overall context of Curiosity’s travels, see Pinpointing Curiosity’s location in Gale Crater.) The rover is right now just off the left edge of the photograph, on the white ridge dubbed Vera Rubin Ridge visible in the uppermost left. This week it completed the last planned drill sampling on that ridge, and it will soon descend off the ridge and begin heading along the yellow route up the mountain. The white dots along its future route are the locations of recurring slope lines, believed to be seasonal seeps of brine coming from below and causing gentle landslides that darken the surface. As you can see, they hope to get very close to the first seep, and will observe the second from across the canyon from a distance of about 1,200 feet.

The peak of Mount Sharp is quite a distance to the south, far beyond the bottom of the photograph. Even in these proposed travels the rover will remain in the mountain’s lowest foothills, though the terrain will be getting considerably more dramatic.

Below is a full resolution section of the image showing the spectacular canyon to the south of that second seep. This is where Curiosity will be going, a deep canyon about 1,500 feet across and probably as deep, its floor a smooth series of curved layers, reminiscent of The Wave in northern Arizona. The canyon appears to show evidence of water flow down its slopes, but that is unproven.
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