InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 Options

[PaulH51]

Animated GIF Sol 502 from IDC shows a little re-positioning on the end cap and possibly a pre-loading.
Maybe this is in preparation for another hammering session?

[Decepticon]

I have a Good Feeling about this!

[atomoid]

a couple of those frames from sol502 had enough parallax for stereograms:

[PaulH51]

Sol 509 'Hammer Time' (animated GIF)

IDC 14 frames (reduced is size to meet the upload limits) but no other processing

[MahFL]

Sol 509 'Hammer Time' (animated GIF)

Looks like the mole went in about 3/4in.

[JRehling]

Interestingly, right around the time that Insight launched, researchers came up with an interesting result, and a bit of advice for future heat-flow experiments, based on the results from Apollo.

It was too late for Insight to benefit from this lesson, but at least we can be sure that Insight did not disturb the locale as much as an Apollo mission did. And now, we hope that we get the instrument underground so that that matters.

https://eos.org/research-spotlights/the-cas...-finally-solved

[Quetzalcoatl]

Bonjour,

It seems to me that there has been a clear evolution of the situation.

I feel like the bucket is almost at ground level...

Let’s wait for Paul’s Gif and hope for an article by Tilmann Spohn...

https://mars.nasa.gov/insight-raw-images/su...0000_0817M_.JPG

[Quetzalcoatl]

In this picture, my diagnosis seems more obvious :

https://mars.nasa.gov/insight-raw-images/su...0000_0817M_.JPG

[stevesliva]

It was too late for Insight to benefit from this lesson, but at least we can be sure that Insight did not disturb the locale as much as an Apollo mission did. And now, we hope that we get the instrument underground so that that matters.

6 years and the subsurface was still warming up? How long until equilibrium? I wonder if the number of lunar days matters, and I suppose 6 years is only 72 days.

[Jim In ILLINOIS]

6 years and the subsurface was still warming up? How long until equilibrium? I wonder if the number of lunar days matters, and I suppose 6 years is only 72 days.

The foot prints and other surface disturbances effect how heat is absorbed from the sun so maybe you should ask how long they will last.

[rlorenz]

6 years and the subsurface was still warming up? How long until equilibrium?

'Equilibrium' is not a straightforward concept here. The basic issue is the propagation of a surface disturbance (and for the principal goal of HP3, heat flow, all solar effects - diurnal, seasonal, etc. - are 'disturbances') into a conductive medium : this is a depth- and time-dependent effect.

Basically the e-folding propagation distance is (kappa * tau)^0.5, where kappa is the thermal diffusivity (typically 1E-7 to 1E-6 m^2/s for regoliths, or most materials) and tau is the time in seconds. You can assess the relevance of this length scale, by substituting how long it takes a hot potato to cool down from some initial condition, or a pea, or an asteroid...

Anyway, the reason HP3 needs to pull the sensors down to 3-5m is to get below the seasonal (annual) heat wave (tau~7E7s). Note that surface disturbances with a longer timescale will propagate deeper, and could influence the interpretation of the temperature gradient into a geothermal heat flux. I wrote a paper (Icarus, 2015, I think) showing that if the Little Ice Age on Earth (200-1000 yrs, tau ~ 6E9-3E10s) were due to a change in solar constant, there might be a measureable change in the Mars subsurface temperature gradient at the depths accessible to HP3 (and down to some tens of meters). There is a LIA signal in Greenland ice cap temperature profiles. Confidently attributing a measurement on Mars to such an effect would be a challenge (you'd be better off on the moon, I guess). [NB there is some evidence, notably the weaker climatological signatures in the terrestrial southern hemisphere, that the temporal association of the LIA with the Maunder Minimum in sunspots, and thus a possible reduced solar constant, is coincidental, and that the LIA was caused by e.g. volcanic effects]

Anyway, if HP3 does get going and gets down to 3m+ depth, the near-surface temperature changes due to any albedo effects by soft-landing propulsion will not matter, they will not have had time to propagate down.

[Quetzalcoatl]

In view of this picture, I have the unpleasant feeling that the probe is now practically lying on the ground ...

https://mars.nasa.gov/insight-raw-images/su...0000_0817M_.JPG

[stevesliva]

In view of this picture, I have the unpleasant feeling that the probe is now practically lying on the ground ...

https://mars.nasa.gov/insight-raw-images/su...0000_0817M_.JPG

The context camera can me zoomed to show the angle:

[JRehling]

That's superb insight (no pun intended), Ralph. It is certainly a priori surprising to have a system still seeking equilibrium after years, but that just speaks to how different situations like this are from our everyday experience.

I've felt the frosty chill in two different caves on two different hot, summer Midwestern days (~12C in the cave, ~30C at the surface), however, which makes it clear that a few months is not enough time for equilibrium to be reached at that particular depth – not even close – so a few years is not wildly outside that range.

It may also be worth noting that Apollo 15 messed up the surface a lot more than, say, Apollo 11, and certainly vastly more than Mars Insight. They had two astronauts and a car operating on three different EVAs. The effect certainly would have been less if one astronaut had walked down the ladder, installed the heat probe, and then they blasted off. (And, speculation on my part – what was the contribution of powered descent and ascent? Mars Insight only has descent.)

[Quetzalcoatl]

The context camera can me zoomed to show the angle:

Thank you Steve,

I had imagined an even more critical situation