Mueller submits report, ends investigation

Special Council Robert Mueller today submitted his report to his new boss Attorney General Bill Barr at the Department of Justice, officially ending his two year long investigation that was supposedly aimed at proving collusion between Donald Trump and the Russian government in order to get him elected.

In those two years, Mueller made a few indictments, none of which had anything to do with Trump-Russian collusion. Most were process crimes, created during the investigation against individuals for either not answering questions perfectly or because Mueller went on a fishing expedition until he found something. None would have happened had this faux investigation had not been instigated.

Moreover, according to the news story at the link, Mueller is “not recommending any further indictments” with this submission.

Or to put it more bluntly, this was all a sham, aimed at deposing the legally elected president of the United States.

Meanwhile, evidence of real collusion, involving Obama and Hillary Clinton and the Russians, was ignored, and in fact the FBI took hostile actions against those involved in revealing it.

The pro-Iran and anti-Israel Democratic Party

Two stories in the past few days illustrate once again the growing fascist and anti-democratic trends within the modern Democratic Party, trends that every registered Democrat should look at with horror.

First there was condemnation by liberal activist groups like MoveOn and Code Pink of the American Israel Public Affairs Committee (AIPAC). Both also demanded that all Democratic presidential candidate boycott AIPAC’s annual conference. To quote MoveOn’s petition:

“It’s no secret that that AIPAC has worked to hinder diplomatic efforts like the Iran deal, is undermining Palestinian self-determination, and inviting figures actively involved in human rights violations to its stage,” Iram Ali, campaign director at MoveOn Political Action, said in a statement provided first to Politico. Ali said the move should “give a clear insight to 2020 candidates on where their base stands instead of prioritizing lobbying groups and policy people who rarely step outside of D.C.”

None of these claims are true. What AIPAC has done for decades is to support the right of Israel to exist, to oppose Islamic terrorism and the wholesale slaughter of Jews, and encourage the U.S. to work with the only viable democracy in the Middle East, for both Jews and Muslims.

These liberal demands were then followed by the immediate decision by all but one Democratic presidential candidate to skip the conference. What makes this significant is that many of these same Democrats have repeatedly spoken there in the past, and in doing so had expressed positive opinions about the organization.

Now however the Democratic Party increasingly sees Israel and its Jewish population as evil, and instead wish to ally themselves with the Islamic movement, a position that follows the lead of their younger anti-Semitic lawmakers like Ilhan Omar (D-Minnesota).

The party’s desire to link itself to radical Islam is demonstrated by the second story today, in which five Democratic presidential candidates announced their endorsement of Iran and the very bad Obama nuclear deal that the U.S. should never have agreed to and that President Trump wisely terminated last year.

Sens. Bernie Sanders (I-Vt.), Elizabeth Warren (D-Mass.), and Kamala Harris (D-Calif.) declared they’d rejoin the Iran deal if Iran abides by it and so did two less-known candidates: Mayor of Miramar, Florida, Wayne Messam and writer and charity activist Marianne Williamson, reported Al-Monitor on March 19.

Note that there is ample evidence, outlined in great detail at the link, that Iran never abided by the treaty, before or after its signing.

Not all the Democratic candidates made this endorsement, but the trend is clear, nonetheless. The Democratic Party now increasingly prefers to ally itself with nations whose leaders routinely chant “Death to America!” and call for the annihilation of Israel.

And this trend makes sense, considering that party’s willingness in the last few years to abandon or even reject the Bill of Rights, preferring to use force and the power of government to impose their will on everyone. For such a party, being fellow-travelers with dictators and tyrants is not difficult.

If you are an ordinary registered Democrat, you need to reassess your loyalty to that party. It is not the political organization you probably think it is.

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

 

The print edition can be purchased at Amazon, any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.


The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
 

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News

Jezero Crater: The landing site for the Mars 2020 rover

Jezero Crater delta
Jezero Crater delta

At this week’s 50th Lunar and Planetary Science Conference in Texas, there were many papers detailing the geological, topographical, chemical, meteorology and biological circumstances at the landing sites for the 2020 Martian rovers, Jezero Crater for the U.S.’s Mars 2020 and Oxia Planum for Europe’s Rosalind Franklin.

Most of these papers are a bit too esoteric for the general public (though if you like to delve into this stuff like I do, go to the conference program and search for “Jezero” and “Oxia” and you can delve to your heart’s content).

Oxia Planum drainages

These papers do make it possible to understand why each site was chosen. I have already done this analysis for Rosalind Franklin, which you can read here and here. Oxia Planum is in the transition between the southern highlands and the northern lowlands (where an intermittent ocean might have once existed). Here can be found many shoreline features. In fact, one of the papers at this week’s conference mapped [pdf] the drainage patterns surrounding the landing ellipse, including the water catchment areas, as shown by the figure from that paper on the right.

With this post I want to focus on Jezero Crater, the Mars 2020 landing site. The image above shows the crater’s most interesting feature, an impressive delta of material that apparently flowed out of the break in the western wall of the crater.

This image however does not tell us much about where exactly the rover will land, or go. To do that, we must zoom out a bit.
» Read more

Conscious Choice cover

Now available in hardback and paperback as well as ebook!

 

From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

 
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.

 

“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of the Mars Society.

 

All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. All editions can also be purchased direct from the ebook publisher, ebookit, in which case you don't support the big tech companies and the author gets a bigger cut much sooner.

 

Autographed printed copies are also available at discount directly from the author (hardback $29.95; paperback $14.95; Shipping cost for either: $6.00). Just send an email to zimmerman @ nasw dot org.

The changing surface of Comet 67P/C-G

Changes on Comet 67P/C-G after outburst

More results from this week’s 50th Lunar and Planetary Science Conference in Texas! Two presentations today focused on showing the dramatic changes on the surface of Comet 67P/C-G that were documented by Rosetta. The first focused on the changes produced after massive outbursts during the comet’s closest approach to the Sun. The second documented several more evolutionary changes that changed more slowly.

The image to the right comes from the first paper, and shows the changes that took place on the surface following one massive outburst, with the numbers in red indicating unchanged features between the two photographs.

It appears an entire cliff section has disappeared, replaced by a single large giant boulder. Interestingly there is no obvious vent opening for the outburst. Instead, it appears that the eruption occurred below ground, and merely blasted part of the surface into space. As noted in the paper:

We report here on a third cliff collapse that occurred in the southern hemisphere in the Sobek region [7], which corresponds to the neck region in the 67P’s southern hemisphere. Due to the close alignment of the 67P’s
southern summer solstice with perihelion passage, the southern hemisphere is subjected to higher solar input, resulting in higher levels of activity and more intensive erosion. The location of the collapsing cliff in Sobek is consistent with the inferred source region of one of the strong outbursts [previously reported].

The paper also showed evidence of a large boulder more than a 100 feet across moving several hundred feet over a period of seven months.

The second paper showed various changes in a number of depressions and scarps on the smooth flat surfaces near the narrow neck that connected the comet’s two lobes. Examples of this terrain can be seen in high resolution pictures here and here and here and here.

From this data scientist suggest that the neck region is slowly dissolving away, its material in these flat areas flying away because the neck happens to be a region of low gravity.

Leaving Earth cover

Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel, can be purchased as an ebook everywhere for only $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from my ebook publisher, ebookit.

 

If you buy it from ebookit you don't support the big oppressive tech companies and I get a bigger cut much sooner.

 

Winner of the 2003 Eugene M. Emme Award of the American Astronautical Society.

 
"Leaving Earth is one of the best and certainly the most comprehensive summary of our drive into space that I have ever read. It will be invaluable to future scholars because it will tell them how the next chapter of human history opened." -- Arthur C. Clarke

Lava tubes on Alba Mons

Lava tubes on the western slope of Alba Mons

During oral presentations today at this week’s 50th Lunar and Planetary Science Conference in Texas, scientists revealed [pdf] a map showing what they believe are numerous lava tubes flowing down the western slope of the giant Martian volcano Alba Mons.

The image on the right is taken from their paper. The red lines indicate collapsed tube sections, maroon collapsed sections on a ridge, and yellow volcanic ridges, which I assume are external surface flows. From their paper:

Lava tube systems … occur throughout the western flank, are concentrated in some locations, and are generally radial in orientation to Alba Mons’ summit. Lava tubes are typically discontinuous and delineated by sinuous chains of elongate depressions, which in many cases are located along the crests of prominent sinuous ridges. Lava tube systems occur as both these ridged forms with lateral flow textures and more subtle features denoted by a central distributary feature within the flat-lying flow field surface. Significant parts of the sinuous volcanic ridges show no collapse features, indicating a distinctive topographic signature for Alba Mons’ lava tubes.

Alba Mons is in some ways the forgotten giant volcano on Mars.
» Read more

Yutu-2 heads west!

LRO images of Yutu-2 on the Moon
Click for full image.

A new image from Lunar Reconnaissance Orbiter (LRO) shows the path taken by the Chinese lunar rover Yutu-2 during its second lunar day of travel on the Moon. The LRO images on the right, cropped and reduced in resolution to show here, compares the rovers position at the start and end of February. The white arrow indicates the rover, with its Chang’e-4 lander visible between the three craters to the east. As noted by the LRO science team:

LRO passes over any given place on the Moon at least once every month (in the daylight), allowing the westward progress of the Yutu-2 rover to be seen. At the end of February, Yutu-2 was 69 meters from it’s home base, the Chang’e 4 lander; LROC images show Yutu-2 made 46 meters of westward progress during the month of February.

It appears from these orbital images that they are taking the smoothest route, with the fewest obstacles, away from the lander.

Hayabusa-2 to take close look at planned explosive impact point on Ryugu

Flight plan for Hayabusa-2's rehearsal

Beginning today Hayabusa-2 will do a two-day close approach of Ryugu in order to get good baseline images of the point on the surface where they will fire an explosive projectile in the first week in April. As they note:

Currently, we have scheduled the small carry-on impactor operation (SCI operation) for the first week in April. The purpose of the SCI operation is to create a crater on the surface of Ryugu, and it is important to be able to compare the asteroid surface before and after the SCI operation.

The graph on the right shows the flight plan. I expect they will do the same for this maneuver as they have done with previous close approaches, and provide real-time images as they happen.

Air Force’s launch contracting plans under scrutiny

It appears the Air Force wants to decide now which two rocket companies it will use for its launch needs in the 2022 to 2026 time period, and this desire is raising hackles among those companies.

[T]he Air Force will choose only two companies to meet its launch needs from 2022 to 2026, with one provider winning 60 percent of the contracts and the other taking 40 percent. There is no provision to on-ramp other companies during the time frame.

This sets up a rather frantic competition between the incumbents, ULA and SpaceX, and newcomers Blue Origin (with its New Glenn booster) and Northrop Grumman (with its Omega rocket). Moreover, the timing appears to prejudice the competition in favor of the incumbents, which already have existing launch systems the government can assess.

Something is really fishy here. Why does the Air Force need to limit its services to only two companies? And why do they have to make this decision now, three to seven years before the launches will occur? Common sense says you instead issue specific contract bids, for each launch, as they are needed, thus allowing as many companies as possible to compete for the business.

In fact, this policy seems to directly contradict the Air Force’s stated goal, repeated many times in the past few years, to widen competition in the launch industry, both to lower cost and to give the military strategic redundancy in its needed launch services.

China’s future lunar exploration plans

In a poster presented on Tuesday at this week’s 50th Lunar and Planetary Science Conference in Texas, China outlined its future plans for lunar exploration.

Systematically considering the major scientific issues of the Moon and the lunar in-situ utilization resources, Chinese scientists and technical experts have proposed a vision to preliminarily build a research station on the Moon’s South Pole by implementing 3-4 missions before 2035.

The first mission will carry out a comprehensive exploration in the South Pole of the Moon, including the topography, elemental composition and volatile contents of the Moon, and the information on the structure of the South Pole from shallow to deep levels. Water (ice) in the permanent shadow area was detected in-situ to reveal the content, distribution and source of water and volatiles on the surface of the Moon. After that, a sampling return mission will be arranged to collect samples from the South Pole of the Moon and return them to the Earth. In addition to the scientific exploration of the Moon, the utilization of lunar resources should also be taken into consideration. In later missions, lunar platforms will be used to make astronomical or earth observations and to consider the use of lunar resources. [emphasis mine]

China clearly intends to put its footprints on the Moon. It is not fiddling around with an orbital lunar station, as it looks like we are with NASA’s Gateway project. While China explores the surface, we will be stuck in orbit (maybe).

Ariane 6 gets OneWeb launch contract

Capitalism in space: Arianespace announced this week that it has signed a three-launch contract with OneWeb that will use its new Ariane 6 rocket, including the rocket’s maiden flight.

The launch service agreement specifies the use of the qualification launch of the Ariane 62 version, scheduled for the second half of 2020; the two Ariane 6 options (either in its 62 version, accommodating up to 36 OneWeb satellites, or in the 64 version, up to 78 OneWeb satellites) will be utilized starting in 2023.

The OneWeb satellites will be launched by the first Ariane 62 into a near-polar orbit at an altitude of 500 kilometers before raising themselves to their operational orbit.

Because OneWeb is in direct competition with SpaceX for building the first space-based internet satellite constellation, it has looked for other launch companies to put its satellites in orbit. Thus, the business to launch the company’s planned 650-plus satellite constellation has gone to Arianespace, Russia, Virgin Orbit, and others. This in turn appears to have saved Ariane 6, which is going to be more expensive than SpaceX’s rockets and was therefore having trouble getting launch contracts.

Isn’t competition wonderful? It looks like it is going to take us to the stars.

Boeing delays unmanned test flight of manned capsule

According to this story today, Boeing has delayed from April to August its first unmanned test flight of its Starliner manned capsule. It has also delayed the first manned flight from August to November.

NASA refused to comment other to say it would announce new schedules next week. The article also stated this:

The initial April launch was ahead of a United Launch Alliance mission for the Department of Defense in June from the Cape Canaveral launch pad in Florida, so Boeing would have needed to clear the launch pad by the first week in May, one of the sources said, describing the pressure not just on technical issues but also launch schedules at Cape Canaveral.

I suspect the technical issues are related to Boeing’s need to do more tests of the attitude thrusters on Starliner following the leak that occurred in a test last summer.

I also hope that next week’s announcement will reveal a firming up of SpaceX’s schedule. By now they should have a good idea of when they can do their launch abort test reusing the Dragon capsule used during their successful first unmanned test flight in March. That will in turn allow them to firm up the launch date for the first manned flight.

Andrew Yang: the fascist future of the Democratic Party

Want to know what the future of the Democratic Party will be? You need only take a look at the stated presidential goals of Andrew Yang.

Yang’s proposals in the first two stories would violate the first amendment of the Bill of Rights, having government impose its will on both free speech and religion. His proposal in the third story would bankrupt the nation while imposing back-breaking taxes on everyone. The result would be Soviet- and Venezuelan-style socialism/communism. And anyone with even the slightest education can imagine where that will get us.

The fourth story illustrates his uneducated narcissism. He fears that automation and robots are going to put people out of work forever, and wants to use the power of government to fix this danger.

Even if he is right about the dangers of automation, however, what makes him think he is so smart that he has the slightest idea what to do? He doesn’t. No single human ever does on problems of this complexity. Instead, the free market usually answers the problem quite effectively. Remember Aesop’s fable about necessity being the mother of invention?

If automation kills some jobs, others will pop up to replace them. This is what happened in the 1960s and 1970s when the first wave of panic occurred over automation. Then there were numerous articles about how automation was going to put everyone out of work. It never happened, and it won’t happen in the future.

Yang will probably not be the Democratic Party candidate for president. Still, his stance and nonchalant willingness to violate the Constitution to impose his will on others is very typical of most young Democrats. This is where that party is heading, even as it embraces bigotry and anti-Semitism, while working to corrupt the election process.

Yang is typical of the young Democratic Party. That future should send chills up the spine of every free American. As I’ve said repeatedly, they’re coming for you next.

Streaky Mars: Slope streaks and recurring slope lineae

New recurring lineae on Mars
Click for source paper [pdf].

Numerous presentations at this week’s 50th Lunar and Planetary Science Conference in Texas have focused on two different changing features on the Martian surface, dubbed slope streaks and recurring slope lineae (or RSLs, an example of an unnecessary and unwieldy acronym that I avoid like the plague).

These apparently are considered two different phenomenon (with some overlap), something I had not recognized previously. For example, one presentation [pdf] this week described slope streaks as:

…gravity-driven dark or light-toned features that form throughout the martian year in high-albedo and low-thermal-inertia equatorial regions of Mars. The distinctive features originate from point sources on slopes steeper than ~20°, follow the topographic gradient, extend or divert around small obstacles, and propagate up to maximum lengths of a few kilometers. The streaks brighten with time, sometimes become brighter than their surroundings, and fade away over timescales of decades. [emphasis mine]

An example can be seen here. This is in contrast to the recurring slope lineae, shown in the image above, which another paper [pdf] described as:

…dark linear features that occur on the surface of steep slopes in the mid-latitudes of Mars. These areas are warm, occasionally exceeding temperatures of 273-320 K. [Lineae] recur over multiple years, growing during warm seasons and fading away during colder seasons. Their apparent temperature dependency raises the possibility that liquid water is involved in their formation. [emphasis mine]

I have highlighted the key differences. While slope streaks are long lived and change slowly, lineae change with the Martian seasons. And the slope streaks appear to exist at lower latitudes. These difference means that the formation process of each must be also different.

The problem is that scientists still don’t know what causes either, though they have many theories, involving both wet and dry processes.

Most of the presentations at the conference this week focused on the recurring lineae, which I suspect is because of their seasonal aspect. This feature strongly suggests a water-related source for the lineae, and everyone who studies Mars is always focused on finding sources on Mars where liquid water might be found. Also, slope streaks appear more often in dunes, which also strongly suggests a dry process. One paper, however, did a comparison study of lineae with one specific kind of dune slope streak to see if the freatures might be related.

The most interesting result [pdf] for all these papers documented the apparent increase in recurring lineae following the global dust storm last year. The image at the top of that post is from this paper, and shows a fresh lineae where none had been prior to the storm. From the paper’s abstract:
» Read more

Land of mesas

Ariadnes Colles
Click for full image.

Cool image time! The Mars Odyssey science team today released the image on the right, cropped and rotated to show here, of a region on Mars named “Ariadnes Colles.”

The term colles means hills or knobs. The hills appear brighter than the surrounding lowlands, likely due to relatively less dust cover.

This is certainly a place with lots of hills, or to be more precise, mesas, as many of them seem to be flat topped.

The lack of dust cover on the tops is probably because, like on Earth, the winds blow much better once you get a bit above the surface. (This is why sailing ship builders kept adding higher and higher sails to their ships, until the top sails of clipper ships rose a hundred-plus feet above the deck.) These better winds clean off the mesa tops, just as they did to the solar panels on the rovers Opportunity and Spirit several times during their long missions.

Ariadnes Colles is another example of Martian chaotic terrain. Since this region is located deep in the cratered and rough southern highlands of Mars, the erosion that created these mesas was likely not water-flows. Was it wind? Ice?

Your guess is as good as anyone’s.

A review of the Trump administrations’s SLS/Orion reprogramming options

Link here. This is a nice summary of the technical and political options being considered for the first unmanned Orion test flight, presently scheduled for June 2020, including replacing SLS with commercial launch rockets.

The article also noted that NASA is also looking at simplifying that test flight, because both SLS and Orion are behind schedule and this would make using a commercial rocket easier.

The currently baselined EM-1 [the test] mission would launch an uncrewed Orion spacecraft on a trans-lunar injection (TLI) trajectory; once released from the launch vehicle, it will fly solo for the first time. The Orion would then make two large engine burns to insert itself into a Distant Retrograde Orbit (DRO) around the Moon. Depending on the time of year, Orion would stay in the DRO for a half or one and a half orbits before making two more large engine burns to return to Earth. Preliminary analysis indicates a June, 2020, launch of the full-up mission would fall into the “long-class” category, with Orion staying in a DRO with a twelve-day long period for one and a half laps and flying a five-week long flight.

Prior to Administrator Bridenstine’s announcement of the alternate launch study for EM-1, notes passed to [this website] indicated that NASA Human Exploration and Operations Mission Directorate (HEOMD) Associate Administrator Bill Gerstenmaier had sent out a memo in early March indicating that studies to look at ways to keep the EM-1 launch in 2020 could not compromise any of the mission objectives; besides that, everything else was on the table.

The highest priority objective of the EM-1 mission is a lunar-velocity reentry test of the redesigned Orion heatshield, along with a full end-to-end test of the re-entry sequence and an in-space demonstration of Orion systems, many of which are flying for the first time.

Although Bridenstine’s public comments stressed flying EM-1 as a lunar orbit mission, there has been speculation that launching Orion out to near lunar distance without attempting either a lunar orbit or a lunar flyby could meet the highest priority objectives. Dropping the lunar orbit requirement or lunar flyby options would also relax launch opportunity constraints created by flying to the Moon and could perhaps reduce launch vehicle performance requirements enough to drop the [Earth orbit rendezvous] proposal and [docking] development work. [emphasis mine]

To use commercial rockets and still go into lunar orbit would require at least two commercial launches to get the required material up to orbit. It would also require developing Orion’s docking software now, something NASA had not planned to do until prior to Orion’s third flight several years hence. Avoiding lunar orbit means they can use a single Falcon Heavy launch and avoid these issues.

The highlighted phrase above indicates the most important priority of the test flight. This does not require lunar orbit. In fact, the Apollo mission tested its heat shield without leaving Earth orbit, and Orion can do the same.

It is still bothersome to read how haphazard NASA’s SLS/Orion program remains. They aren’t doing enough testing, their future flights are always in flux for political, schedule, and budgetary reasons, and they always seem to be in too much of a hurry to fly humans on very unproven vehicles. If NASA’s corrupt safety panel applied the same standards to SLS/Orion as it does to SpaceX and Boeing, the whole program would be shut down. It does not, because safety isn’t really its purpose. That panel’s goal is to serve NASA’s bureaucracy, and to protect its biggest projects (SLS/Orion) from any competition.

As for replacing SLS for that first Orion test flight, we shall see. The political forces opposing such a move are vast, and wield a lot of power.

Confirmed: Ryugu is a rubble pile

Close-up of Ryugu's surface
Click for source paper [pdf].

At a special session today dedicated to results from the Hayabusa-2 probe to the asteroid Ryugu at the 50th Lunar and Planetary Science Conference in Texas, scientists confirmed from numerous data and images that the asteroid has a low density, is covered with boulders and pebbles, is very porous, and is thus a rubble pile that is held together by gravity, barely.

From their lead presentation [pdf]:

The estimated total porosity is even higher than that of rubble-pile asteroid Itokawa (44 ± 4%), indicating that asteroid Ryugu is also a rubble pile. This is consistent with a theory arguing that all Solar System bodies with diameter of ~1 km should be rubble piles and might have formed from reaccumulation of fragments generated by catastrophic disruption events of ~100-km sized parent bodies.

They also posit that the asteroid’s diamond shape is caused by the asteroid’s 3.5 hour rotation, which causes its weak rubble pile structure to be easily pulled to the equator, and then outward.

Another paper [pdf] did crater counts, and found that there are fewer large craters than one would expect.

The density of large craters (D>100 m) on Ryugu is lower than the empirical saturation level and its slope is steeper than that of the saturated distribution, suggesting that craters larger than 100 m are not saturated and the size distribution reflects the crater production function. However, craters smaller than 100 m are significantly under-saturated, suggesting that some crater erasure processes such as seismic shaking and armoring effect are active on the Ryugu surface. Based on cratering chronology model for the main belt, the surface age of Ryugu is estimated to be 5–200 [million years] from the size–frequency distribution of craters larger than 100 m.

In other words, this rubble pile is constantly being shaken by its rotation and time and later impacts, which steadily rewrites the surface.

If this asteroid was headed to Earth, I imagine the only safe solution to prevent disaster would be to slowly and gently deflect it so it only flies past. To do this will require an arrival far in advance of the schedule impact, to give time for the deflection process to work.

Snow on Mars?

Snow on Mars?
Click to see full image.

At today’s presentations at the 50th Lunar and Planetary Science Conference in Texas, scientists showed images and data [pdf] suggesting that many of the Martian gullies found on cliff faces are formed when the dust layer protecting underlying snow gets blown away and the exposed snow/ice then melts.

The image on the right was taken by the high resolution camera of Mars Reconnaissance Orbiter (MRO) in 2009, and has been cropped to post here. The white streaks are what they suggest is exposed ice/snow.

From their paper [pdf]
» Read more

Test drone maps ice cave in Iceland

Engineers have tested a prototype lidar-equipped drone by flying it through a lava tube in Iceland and using it to automatically map the tube.

While a cave-exploring drone on Earth may use propellers, free-flying spacecraft exploring caves on the Moon, where there is practically no atmosphere, or in the thin air of high altitude lava tubes on Mars’ giant volcanoes, would have to use small thrusters. The mission of the terrestrial drone deployed at the Lofthellir Ice Cave focused on validating the idea of using a drone-equipped LiDAR to safely navigate and accurately map rock and ice inside a dark lava tube in the absence of GPS or any prior map.

Under a research contract with NASA, Astrobotic has developed a custom navigation software product, known as AstroNav, to give drones and small free-flying spacecraft the ability to autonomously explore and map subterranean environments. AstroNav employs both stereo vision and LiDAR, works without GPS or previously stored maps, and can operate in real-time while a novel environment is explored at a high rate of speed.

…”The Astrobotic drone and LiDAR performed exactly as we had hoped, and was able to help us map the Lofthellir Lava Tube in 3D within minutes” says Lee. “We now have a highly accurate model of the shape and dimensions of the cave, and of the configuration of its many rocky and icy features, such as rock falls, ice columns, and micro-glaciers.”

The concept is an excellent one, especially for exploring the caves and pits of Mars. This test however only checked out the lidar. A drone that could do this on either Mars or the Moon does not yet exist.

I have posted their video of the flight below the fold.

Note: Thanks to reader Eddie Willers for noting that I mistakenly located this research in Greenland, not Iceland. Post now corrected.
» Read more

A rock on Bennu

A rock on Bennu
Click for full image (which is rotated 180 degrees).

Cool image time! The OSIRIS-REx science team today released a close-up image of the surface of the asteroid Bennu. The image on the right is a cropped and rotated section of that image, focusing on the image’s star, its largest rock.

The boulders on Bennu’s surface sport a variety of surface textures, from smooth, to hummocky, striated, and crumbly “cauliflower” in nature. The large boulder in the image center is ~92 ft (~28 m) across and has a somewhat round shape, though many smaller boulders surrounding it are very angular. Some of these appear to be fragments that may have disaggregated from the central boulder and display layering effects that may reflect some of the properties of their mineral composition. Other boulders show signs of surface exfoliation and fractures that may have been caused by impacts, mechanical weathering, and other forms of rock breakdown active on Bennu’s surface.

The image was taken from less than a mile away, and shows a spot near the asteroid’s south pole.

Why the larger boulder has a rounded look, but the pebbles around it are jagged, is a puzzle.

The science team also revealed today that they have detected plumes of particles being released from the asteroid’s surface. They have also found Bennu to present them with the same problem faced by the Hayabusa-2 team at Ryugu: The asteroid is far rougher than expected.

The higher-than-expected density of boulders means that the mission’s plans for sample collection, also known as Touch-and-Go (TAG), need to be adjusted. The original mission design was based on a sample site that is hazard-free, with an 82-foot (25-meter) radius. However, because of the unexpectedly rugged terrain, the team hasn’t been able to identify a site of that size on Bennu. Instead, it has begun to identify candidate sites that are much smaller in radius.

Hayabusa-2 schedules explosion on Ryugu

The Hayabusa-2 science team has scheduled April 5 for when it will use the spacecraft to fire an explosive device into Ryugu to create a crater and debris cloud.

The probe is scheduled to detach a device loaded with explosives some 500 meters away from Ryugu. The device will set off the explosives using a timer some 40 minutes later and launch a copper “impactor” weighing about 2 kilograms into the asteroid’s surface.

The target point is several hundreds of meters away from where the space probe first touched down. The mission will require the spacecraft to move quickly to the other side of the asteroid so it won’t get hit by flying shards from the blast. A detached camera will shoot the moment of impact.

JAXA will analyze the size and shape of the crater, and how rocks fly off in a bid to collect underground samples for possible clues to the origin of the solar system.

This is different than the touchdown last month, as the spacecraft itself will not get close to the asteroid.

Cost for Mars 2020 rover up 15%

Because of cost overruns in building three instruments for the Mars 2020 rover, its total budget will rise by 15%, forcing NASA to trim budgets elsewhere in its planetary program.

There are small efficiencies to be gained internally in Mars 2020, Glaze says, which, like its predecessor Curiosity, is being developed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. Some work can be postponed, some timelines tightened; the end of the Opportunity rover, which expired late last year on Mars, will help. But it is expected the costs will largely be borne by trims to the operations of existing Mars missions and funds the agency sets aside for future missions, including the return of the rock samples that Mars 2020 will collect. “We tried to spread it so no one is feeling all of the pain,” Glaze says.

For a government program costing almost $2.5 billion, this overage is remarkably small. What is more significant is that the rover appears on schedule for launch in July 2020.

Mars likely has many large and extensive cave systems

Mamers Valles

More caves on Mars! This week the Lunar and Planetary Institute and the Johnson Space Center are jointly holding the 50th Lunar and Planetary Science Conference in Texas. I have been going over the program, and will be posting reviews of some of the more interesting results all this week.

We begin with caves, which should not be surprising to my regular readers. As a caver who also knows their value for future space colonists, I am always attracted to new discoveries of cave passages on other worlds. Today’s however is a doozy.

The image to the right is of Mamers Valles on Mars, what scientists have dubbed a fretted valley, a common feature in the transition zone between the low altitude northern plains and the southern highlands. It comes from a paper [pdf] with the typically unexciting scientific title, “Fretted channels and closed depressions in northern Arabia Terra, Mars: Origins and implications for subsurface hydrologic activity.”

What the scientists really means here is that their research strongly suggests that Mars has a very large and very extensive number of underground drainage systems, which have caused collapses on the surface that often resemble meandering river canyons, such as seen above. As they explain:
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DARPA’s satellite servicing mission adrift

Capitalism in space? DARPA’s program to test a satellite servicing mission appears in serious and complex trouble with the termination by Maxar (previously called SSL) of its contract to build the structure, or “bus”, of the robot.

What makes this more complicated is that the company building the actual servicing payload is continuing its work.

While Maxar will no longer be providing the satellite bus, work on the servicing payload continues. Among the companies involved in that effort is Praxis, a company handling planning for mission operations of the RSGS servicing system, such as how the system will safely grapple the target satellite. “For our day-to-day operations, that hasn’t really affected us. We’re pretty far along on the payload development,” said Tony Marzi, general manager of Praxis, during a presentation at the MIT New Space Age Conference at the Massachusetts Institute of Technology here March 15.

DARPA is thus calling for proposals to launch this payload.

The irony here is that this DARPA project was under criticism from the start, even to the point that a competing satellite servicing company, Orbital ATK, sued the agency. That company, now part of Northrop Grumman, was building its own privately funded servicing robot, and considered DARPA’s effort to be unfair in that it provided direct government subsidies to its competitors.

While Orbital ATK lost its suit, it now appears it has won the competition — assuming it eventually launches its own mission.

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