Quick recap of arm activities: on sol 417 the scoop was lifted off the soil so the pit could be imaged, and then its tip was pushed down into the surface a bit further out than the hole. I thought that might be a prelude to trying to pull some soil into the hole. On sol 420 the tip of the scoop was pushed down on the far edge of the hole, causing a bit of wall collapse into the hole.

Phil

This article discusses the (relatively well understood) present nature of and (not at all well understood) origin of the martian duricrust.

"Evidence of water and salt is apparent in the abundant duricrusts (weakly-cemented soils) observed on Mars. These duricrusts, and the soluble salts that cement them, are observed at every landing site on Mars, and remote sensing reveals that salts and duricrusts are globally widespread."

https://www.hou.usra.edu/meetings/lpsc2019/pdf/3077.pdf

"Saline" means "solution of salt in water." One way or another, salt was dissolved in water here. The details of the dynamics are still not apparent.

Ooh, thanks, very interesting article!

Eh, depends on what UNDERSTOOD means.
-"There is a layer of hard stuff all over mars".
-"We have identified these %s of cations (K/Na/Ca/Mg) and these percentages of anions (various ITES and ATES) and have confirmed this with spectrophotometry in the lab and in the field."

I spent MANY hours in a grad-school laboratory running ion-chelation-spectrophotometry standard curves for every soluble cation we could find. Even ran samples in the hot lab to see if we could detect isotopes.

Measuring the spectrum of duricrust, in one area, and understanding what it is made of?
Different things entirely.

Here is a graphic summary of the mole operations since the support structure was lifted off the mole.

Phil

Click to view attachment

Interesting paper - seasonal water frost on Mars could form surface brines on the shady side of boulders, at around 30' latitude. So, northern side of northern hemisphere boulders, southern side of southern hemisphere boulders might show signs of recent liquid water.

Now, if you INVERT a round boulder, you get a crater. A crater has identical-but- inverse angles of incident sunlight falling on the surface. So, perhaps we should look for evidence of recent brines in the shaded cusp of craters. So, southern rim of northern hemisphere craters and northern rim of southern hemisphere craters- the place where the last shade would be.

Now, which part of the crater rim is Insight nearest to ? North South East, West?

Salt water may periodically form on the surface of Mars
https://www.marsdaily.com/reports/Salt_wate...f_Mars_999.html

Mars: Quantitative Evaluation of Crocus Melting behind Boulders
https://iopscience.iop.org/article/10.3847/1538-4357/ab612f

Sol 434: Looks like they've pinned the top of the mole next to the ribbon cable, risky but looks like they're setting up for a push...
Click to view attachment

Now THAT is what's known as a calculated risk. Fantastic work to set the scoop where it is, well done. A huge risk but with potentially huge rewards. Go for it!

"He who dares wins".

If the sand here is similar to a thin cooked layer over the top of a soufle, then maybe the scoop can follow the mole into the hole!?

Looks like they will try out pressing the backcap itself, i guess to get a handle on how it reacts, then fill the hole by scraping the adjacent soils into it and pressing on the soil to see if that works.
It appears retrying the backcap approach after the hole has been filled isn't the first approach on the list, implying they seem to think enough friction will be created in that configuration to simply press the soil and see if the hammering is enough. apparently they are reserving the risk of the holding-backcap approach for later.
Latest from Leonard David update 2/18

A few more details in this press release from JPL: https://mars.nasa.gov/news/8612/mars-insigh...e/?site=insight



Next week makers a year since the mole first got stuck! Let's cross our fingers once more.

And the complete DLR blog now public.

Sol 441, tiny movement? Small cap press, or possibly a hammer stroke or two.
Most of what we see in this animation (GIF) are shadow changes, but I believe there is a small movement as well.
Click to view attachment

The landing area around InSight is very level, but does anyone know what can be seen in the distance of this shot? Is it a small hill? Edge of a crater? It looks like you can see some wind-blown sand on it.

Check out post 389 in this thread for an identification.

Also:

http://www.unmannedspaceflight.com/index.p...mp;#entry246684


Phil

Good evening to you all,

For my first post, I offer you some news from SEIS. Six articles published today are presented in the following links. For non-francophones, links in French will certainly be easily understood with a machine translator. Sorry about my bad English.

https://www.nasa.gov/feature/jpl/a-year-of-...ht-mars-mission

In French :

http://www.ipgp.fr/fr/sismologie-martienne...ture-de-planete

https://presse.cnes.fr/fr/premiere-annee-de...ues-surprenants

No problem, I grew up in Montreal!

Merci beaucoup

Hello everyone, special thanks to Steve and Paul,

Recent interview given by Philippe Lognonné, Principal Investigator, Instrument SEIS sur InSight (NASA) and Responsable-adjoint de l'Equipe Planétologie et Sciences Spatiales de l'Institut de Physique du Globe de Paris, entre autres.

I deliver a translation (machine)

Original link : https://lejournal.cnrs.fr/articles/insight-...ous-sol-martien

Arriving on Mars more than a year ago to study the earthquakes, the Insight mission has just delivered its first results. Geophysicist Philippe Lognonné explains the stakes.
You are a geophysicist at the Institut de physique du globe de Paris1 (IPGP), a professor at the University of Paris and the principal investigator of the seismeter. What are the objectives of the Insight mission?

Philippe Lognonné : Launched in May 2018 and arriving at its destination in November of the same year, Insight is a NASA mission that is equipped with the seismometer SEIS. This instrument was developed between the Centre national d'études spatiales (Cnes) and the IPGP, with the help of European industrial and academic partners, and with Nasa’s Jet Propulsion Laboratory (JPL). It aims to study seismology and the depths of Mars, still very little known. The operations on Mars are done by the Cnes and the IPGP, which distributes the data to the international community via its datacentre.

What were the main challenges?

P. L. : It all started with the Viking mission, launched in 1975, which had seismometers on both landers. The first one never worked, while the other provided skewed data. Indeed, all the vibrations reported were due to the Martian winds shaking the aircraft. For Insight, Seis was deployed on the ground by a robotic arm and then covered with a dome that protects it as much as possible from atmospheric disturbances. The wind still has an impact, but it has no impact with Viking. Atmospheric currents still cause major disturbances during the day, but this background noise drops drastically, by a factor of 100, between 17 and midnight, solar time. Thanks to this, we were able to measure signals ten times weaker which rewards the efforts of the IPGP technical team that designed this sensitive sensor. Even if this noise will surely evolve according to the seasons and will probably increase during storms, Insight is today the least noisy seismic station in the solar system! This very low level of noise allows it to detect Martian earthquakes: if the Earth knows very strong earthquakes of magnitude of seismic moment 5, 6, 7 or even 8, on Mars, we were expecting earthquakes around a magnitude 4. There is indeed no more tectonics of the plates on the red planet. But when you go from magnitude 7 to magnitude 4, you divide the wave amplitude by a factor of 30,000.

How did the first seismic scan go ?

P. L : We started acquiring data in February 2019, but we only detected very small events in the first two months. We finally had a high-frequency, high-amplitude event on April 7. We were of course very surprised and excited, even though the magnitude was only 2.1. It was also by chance that this earthquake occurred just before the 130th anniversary of the very first earthly seismological measurement, carried out by Ernst von Rebeur-Pacshwitz in Postdam on 17 April 1889. At the end of September 2019, eight of the detected low frequency earthquakes had primary (P) and secondary (S) seismic wave phases, and three of them had measurable wave polarization. These two waves are essential for measuring the distance of the epicentre of an earthquake when only one seismometer is available. The polarization of these waves gives us their direction of arrival, which ultimately allows the localization of the event. These polarized waves also allowed us to discover the presence of a discontinuity in the crust, at a depth of about ten kilometres. In mid-February 2020, the number of detected events is 460. Most are high frequency signals and their origin is not yet clear: small very superficial earthquakes, landslides or collapses of cliff areas are candidates for their origin. But the number of earthquakes with signals below 1 hertz (Hz) is now close to quarantine.

When you took off from Insight, you hoped to measure about 50 earthquakes per year, of which about 10 magnitude are up to 5.5. What is the balance sheet ?

P. L. : As said earlier, the low background noise at night has allowed us to detect earthquakes much weaker than expected, and therefore more numerous. However, the most powerful reached a maximum magnitude of 3.8 or we hoped to see with magnitudes of at least 4.5. A tremor of such intensity indeed generates surface waves, which would inform us about the depths of Mars, such as the thickness of its crust and the structure of its superior mantle, and would allow us much better constraints.So we are still hungry, waiting for these bigger earthquakes, but we also had some good surprises. So we came up with the idea of doing seismology without seismic activity, using instead the interactions between the soil and the atmosphere. Whirlwinds of dust, called dust devils, form on Mars. They cause a depression at ground level that Seis and the Insight weather station were able to detect when they passed close enough. We deduced the properties of stiffness and elasticity of the soil up to a depth of about ten meters. It’s a new form of seismology !

How is the first results revealed ?

P. L. : Six publications are synchronized: five in Nature Geoscience and one in Nature Communications. They are not all associated with seismological experiments, since two deal with atmospheric and magnetic measurements and one with the geological context. In addition to a general article, two focus on Seis and present our main results. The first discovery is, of course, in the measure of a shock large enough to be sure that it is indeed an earthquake. Then, the three largest earthquakes, two of magnitude of about 3.6 and one of magnitude 3.1, all come from the same region: Cerberus Fossae. This huge volcanic fault system extends 1,600 kilometres from the Elysium Plain, where Insight landed. We knew that the area had been geologically active over the last few tens of millions of years, but we did not expect to detect our three largest earthquakes. It’s a nice surprise. Finally, a third major result is the confirmation of a priori: the Martian seismic activity lies between that of the Earth and that of the Moon. It is ten to twenty times more important than on the Moon, but two to three times weaker than on our planet, if we exclude earthquakes due to plate tectonics. With other comparative analyses between the Moon and Mars, such as on wave attenuation and diffraction, we can now initiate planetary seismology compared. In addition to these publications in Nature Geoscience, we are expecting a special edition of the American Geophysical Union, and by the summer we should reach a dozen or even twenty articles.

What’s next for Insight ?

The nominal mission will last another year, but we will extend it by at least another two years. We hope that a stronger earthquake will occur in the meantime, in order to improve our models of the structure of Mars. It’s like a French seismological station is trying to detect a magnitude 5 event in Europe. We have to wait, because Mars is much less active than Earth. In any case, we have already collected high quality data and these first articles are the result of the work of the French, European and American teams of Insight, with a strong collaboration with the ETH of Zurich in Switzerland and the JPL. In France, Aymeric Spiga of the Laboratoire de météorologie dynamique co-hosted the analysis of atmospheric data and several supplements of seismological analyses were co-hosted by French researchers, such as Naomi Murdoch of the Higher Institute of Aeronautics and Space for Dust Modelling, Clément Perrin of the IPGP for seismotectonic analyses of Cerberus, Ludovic Margerin of the Institut de recherche en astrophysique and Benoît Tauzin of the Laboratoire de géologie de Lyon: Earth, planets, environment for seismological analysis, among other things.
Much work remains to be done to better understand and analyze Martian seismology. As is often the case in science, the first publications present fascinating discoveries, but these interpretations and results can evolve with the arrival of new data.


PS : This kind of long text is not very common on UMSF. If I hurt, please tell me.
I do not process images and my contributions would be reduced to providing information.

I'm sure the admins will advise if they'd prefer it done via links or whatever, but I for one appreciate such informative posts. Links can break over time whereas this will remain here to be referred back to in future. We used to have more long written posts in the past, including valuable quotes or translations like yours but also substantial original contributions to scientific discussions.

Thanks for your reply.

The mole keeps making me thinking of certain movie endings, where we'll wake up one morning and see gratefully that it is just gone (underground).

I know that the situation is very serious, but for me there is something a little funny in the fact that a lot of people in the world are constantly staring at this one little device with a beating heart ... will it move or not? and which way?

I apologize for this bit of profanation

A French proverb : L'espoir fait vivre (Hope makes your life)

In Inglish we say "Hope gives life" ?...

Hello,

In addition to post 867, I am offering you a translation of the article published on the CNES website (Centre Nationnal d'Etudes Spatiales) relating to the year of operation of the Insight seismometer on March.

INSIGHT/SEIS: THE VEIL RISES ON THE INTERNAL STRUCTURE OF MARS

More than 100 researchers analyzed the first dataset of the Insight mission’s SEIS seismeter. Thanks to 3 earthquakes, among the 171 events detected between January and September 2019, they establish that the upper crust of Mars is between 8 and 11 km thick and that its numerous fractures are covered with films of liquid water. These results are published in Nature Geosciences on February 24, 2020.

Original link :
https://insight.cnes.fr/fr/insightseis-le-v...interne-de-mars

3 SEISMIC NOISE PERIODS :

On 18 December 2018, the Insight lander arm deposited the SEIS seismeter coordinated by the CNES on Mars. Analysis of the 1st dataset of its VBB sensors reveals the existence of 3 typical periods of seismic noise related to atmospheric activity thanks to the recordings of the meteorological station attached to the lander.

From sunrise to sunset : the air heated by the Sun beats the ground. SEIS records many noises related to atmospheric turbulence.

From sunset to midnight : Mars is extremely quiet with seismic noise about 500 times lower than seismic noise on Earth. This noise is the lowest ever measured by a seismic station!

From midnight to sunrise: a light breeze from the southwest touches the surface and generates seismic noise by deforming the ground under air pressure.

The extreme sensitivity of SEIS makes it possible to detect the smallest vibrations of the ground such as those related to the passage of dust devils (NDLR: dust tornadoes). We expected it, this first data set confirms it: SEIS will teach us a lot of new things about the Martian atmosphere» says Philippe Lognonné, professor at the University of Paris, geophysicist of the IPGP, Scientific Director of SEIS and 1st author of the article published in Nature Geosciences.

TOP CRUST THICKNESS : ABOUT 10 KM

From January to September 2019, the researchers identified 171 seismic events, 20 of which would correspond to earthquakes of magnitude 3 to 4. Three earthquakes were particularly well detected by the French SEIS sensors:

the earthquake of 7 April 2019 (Sol 128 because the 128th Martian day of the Insight mission) estimated at a magnitude of about 2.1
the earthquake of 23 May 2019 (Sol 173) estimated at a magnitude of approximately 3.6
the earthquake of 26 July 2019 (Sol 235) estimated at a magnitude of approximately 3.6.

Thanks to the different arrival times of the P and S waves, the researchers determined the existence of a higher crust of thickness between 8 and 11 km. This top crust of about 10 km is more friable and less consolidated than the bottom crust on which it rests. It has been altered by surface processes and probably also by meteoritic impacts. Below, is a crust with more original and less fractured rocks, with a speed 50% faster, a jump from 2 km/s to 3 km/s. This first series of recordings did not allow us to locate the zone of discontinuity between the crust and the mantle (NDLR: the thickness of the crust as a whole). This would require a stronger earthquake or SEIS recording of surface waves, Philippe Lognonné explains.

https://insight.cnes.fr/sites/default/files...g?itok=ohCS4maP

A FRACTURED UPPER CRUST

Another conclusion of the fine analysis of the recordings of these 3 earthquakes: the upper crust of Mars is very fractured and its faults are covered with films of liquid water. «The velocity of wave propagation in the upper crust of Mars is in values intermediate to the one on the Moon and Earth. This assumes a relatively fractured upper crust. In terms of attenuation of seismic waves, we find a value 3 times greater than on the Moon, comparable to those of crystalline massifs such as the Armoricain massif in France (Bretagne) which suggests the presence of moisture. But don’t imagine large amounts of water, it only takes a few films of liquid water molecules to explain the attenuation of the seismic waves we observe,” insists Philippe Lognonné.

On the CNES side, we are very proud to have succeeded in this instrument which has been complex to develop. A real watch jewel! Its implementation was based on close cooperation between the IPGP, Sodern, foreign partners and the CNES. Today, SEIS delivers its first seismic measurements and this is only the beginning. We are only beginning to lift the veil on Martian seismicity!» concludes Francis Rocard, Head of Solar System Exploration Programs at the CNES.

THE CNES, MASTER OF CLOCKS

In order to link SEIS records to earthquakes or atmospheric phenomena, it is essential to have a good dating of these events. It is the SISMOC, a centre dedicated to the Insight mission at the CNES in Toulouse, that provides scientists with the consistent dating of seismic and meteorological data from the instrument clocks. Now, these clocks — which are more counters than real clocks giving hours have a drift in different time of up to a few seconds a day! This work was anticipated for SEIS and the APSS weather station because it was known that changes in atmospheric pressure would have an impact on seismic measurements. Every second, SEIS sends a clock to APSS. It is retransmitted to SISMOC several times a day with the APSS clock data, which allows us to compare their counter and recalculate the whole with an accuracy of a few ms» explains Ludovic Rochas, SEIS Operations System Engineer at CNES.

HP3

In the article published in Nature Geosciences, the researchers also present the analysis of seismic recordings during attempts to penetrate the ground by the Insight HP3 probe. To provide consistent dating, MOCIS had to find a trick. During the penetration attempts of HP3, we program SEIS to transmit its dating much more frequently to the lander, every minute. These datations are then correlated with those that HP3 sends to the lander». The researchers were able to calculate that the shocks caused by HP3 averaged 9.4 ms to travel a distance of 1.1 m, confirming that the surface soil on which Insight landed is composed of very brittle materials, unlikely to spread rapidly propagating surface waves.

Sol 458 The scoop pushes the side of the mole's end-cap as it sinks a short distance into the ground.
The scoop appears to follow the mole down, did not see any contact with the ribbon in the images we have so far, so a remarkable job by the team in commanding that event. More to come soon.
Attached a still frame as I can't create a GIF at this time, but here's a link to a set of 6 GIFs posted on Imgur and shared via the Reddit sub for InSight by u/grappleone: https://imgur.com/a/hKPFl8y
Click to view attachment

Thank you Paul,

The big question that can be asked (and I think it has been asked before) is what will happen when the bucket comes at ground level ?..

But we’re not there yet...

Once that end-cap goes to ground, its probably be too risky to apply pressure with the blade in an edge-on configuration, so the only safe way forward seems to be to drag in soil from the surrounding surface and completely fill the hole, compacting and applying pressure with the scoop in its flat configuration to produce as much friction as possible, then proceed slowly to see if it remains effective or if it collapses more volume and needs more soil repack at intervals. i am absent any other ideas, but they probably have a tiered set of options in the queue for the next few months.

Its so good to see the incredible SEIS results coming back that more than overshadow any angst and drama associated with the HP2 deployment, as problematic as it has turned out, but even so, its incredibly exciting to be able to have a challenge like this, as it presents so many learning opportunities that wculd never have occurred if everything went as expected, even most other types of instrument deployment failures would be more of engineering lessons and couldn't have presented a necessity to solve unknowns about the physics of different martian soils as this particular scenario does, and i have high confidence it will be overcome, eventually...

I love this realism tinged with optimism.
There is no point in whining.
We have to move on.

Looks like it may be rotating back out this time (becoming more horizontal), rather than heading in ?

Let us remain cautious but hope seems to be reborn...

https://twitter.com/NASAInSight/status/1238...497770228420608

Bonjour,

"Depth is determined by a tether length measurement device (TLM) that monitors the amount of tether extracted from the support structure and a tiltmeter (STATIL) that measures the angle of the Mole axis to the local gravity vector." (From a paper by Tilman Spohn).

Long time ago, I think I read somewhere that by its design the mole would have the ability after it has been tilted by some obstacle and by regaining conditions favourable to its progression, to right its axis of penetration towards the vertical.

To be checked.

The mole is looking rather horizontal in the latest images; I don't have a good feeling about this anymore....

I was surprised that they didn't put pressure on the probe (with the scoop) from the left side in an attempt to make it a bit more vertical. Perhaps the left side was inaccessible to the scoop.

Me too.
Moreover, it would have been desirable that the pressure not be exerted too vertically. But was it possible?

It looks that from the IDC camera but not from the ICC camera. It's maybe 35 or 40 degrees from horizontal. The tilt of it really didn't change during the push test.

https://mars.nasa.gov/insight-raw-images/su...0000_0461M_.JPG



Ever tried to streighten a nail when most of it was buried in some lumber? You end up bending the nail because there won't be much deflection of what is buried but deflection of what is not. That is not to say that will happen here, but if most of the mole is buried (like it is) that would probably require alot of latteral force by the arm to achieve for not much if not zero vertical gain. Might even have some deflection of the arm and put unnecessary stress on the arm actuators or the scoop when trying.

Sounds like a first step for now, tallying the results to see what to do next.. my worry of trying to 'right' the mole is that the soil is so non-cohesive that the void introduced by that action will be replaced by breaking the already somewhat packed soils around the mole currently thus loosening and making its current hole less stable, resulting in less friction than currently exists (but heck im no planetary regolith scientist im just throwing out worries here), anyways, i'd assume they may move on to riskier scenarios like that if all else fails..

Trying to right it could have had more of a success when the mole backed mostly out. I suppose they could let it back out again then try it? The hammering while pushing seems to be working for now so, I'd keep with it.

At the angle the mole is drilling, would it drill right under the seismometer package and would it effect seismic results?

I understand the humor , but it must be said that even if the mole was more 10 km away of SEIS, it would record the hammering.

I will never get tired of the anecdote that Venera 14's surface compressibility arm came down right onto its own camera lens cap, which had popped off and rolled randomly to that location.

It really seems like there is a sentient gremlin at work sometimes.

Click to view attachment

Some arm/mole pressing/hammering? from the lander's IDC camera at “Homestead Hollow” on Sol 472.
Need more ICC images to try to estimate what progress was made.
Streamable version link
Click to view attachment
#SaveTheMole

I found myself watching the shadow since the motion of the arm was nearly parallel to the line of sight. The shadow is more perpendicular and indicates that there was some downward motion but not much – a couple to few cm maybe.

Automatic translation of a short article in a French daily newspaper concerning the difficulties to operate SEIS (Insight mission) in this period of confinement.

Interview with Charles Yana, head of SEIS operations at the Toulouse Space Centre CNES for the Insight mission.

Journalist : Is the Insight mission continuing ?

C. Yana : Yes, everything is still OK on board. We had anticipated the containment period. Fortunately, we are not supposed to send orders to instruments outside our operational centre, SISMOC, based at the CNES space centre in Toulouse. Our teams were able to test telework in real time the day before the start of confinement. Fortunately we are in 2020 ! I can’t imagine this event even ten years ago when, for the beginnings of Curiosity, we didn’t even have a laptop! Thanks to telework and VPN links.

Journalist : How do you work now ?

C. Yana : We are each at home and we do not compromise on the quality of operations because there was no question of producing sequences of commands on a table corner. If we’re wrong, we create problems on Mars, which would be even worse than doing nothing at all. We now use team instant messaging: in the first week, we exchanged 2,000 messages, we are now at 3,000… The email equivalent would have completely drowned us! Everything went very well, but now we’re going to have to face additional difficulties.

Journalist : Which ones are they ?

The European Space Agency has put on stand-by its TGO satellite, we now have only the American Odyssey satellite which reduces our relay capabilities. So we have to operate our seismometer with less bandwidth. Our data flow comes with a lower resolution, which requires more analysis work so as not to miss a major data (dust storm, earthquake). Another concern is that if the large antennas of the Deep Space Network (based in Spain, California and Australia, they make it possible to converse with orbiters) come to know difficulties, we will be forced to do our live communications with very low throughput. One can imagine scenarios up to putting the instrument into sleep but we’re not there yet.

This is a shock!

The mole was suddenly swallowed up by a Mars (or april) fish :

mole and fish

For everyone’s understanding, in France, Italy and a few other countries, what the Americans call “the April Fool’s Day” and named April’s fish.

Action for sol 481 (April 3, 2020) Animated GIF using 6 IDC frames, I note a very slight movement on the science tether (ribbon cable), time stamps annotated on the frame. I believe there could be further images in the pipeline as there is normally a final image taken an hour or two after such events, if so I can create/add an updated animation later.
Edit animation sequence corrected
Click to view attachment

Hello and thank you, Paul,

It seems to me that according to the shadow progression the last two frames were inverted in this gif ?


Except for the shadow and the very slight trembling of the science tether, I do not perceive any significant movement of the mole or the regolith in the vicinity and I even come to doubt that during this sequence a hammering was started ?..

Thanks for the heads-up, I've corrected the anomaly on the animation and re-uploaded the GIF in my post, the frames were assembled in the wrong order, but the timestamps were correct.

Agreed re apparent lack of hammering, maybe they just applied some small amount of pressure on the arm? There was definite movement of the scoop on sol 482, but when I last checked the images were still coming down

Very roughly assembled and resized animated GIF using Sol 489 raw frames from the Instrument Deployment Camera
Shows apparent minor progress? Dancing grains of sand in the scoop and minor collapses of regolith where the scoop was previously pressed into the pit.
Click to view attachment

Update from NASA Insight on Twitter

Progress being made

NASA Insight Twitter Update

Scientific Observations with the InSight Solar Arrays: Dust, Clouds and Eclipses on Mars
R. D. Lorenz et al., Earth and Space Science, in press
https://agupubs.onlinelibrary.wiley.com/doi...29/2019EA000992