68
votes
Why are there mountains/mounds in the centre of craters on the lunar surface?
Oh, I can answer this one. In my structural geology class, we breezed over a few paragraphs on the tectonics of impact craters, but it was in the textbook, and, being space-related, I was intrigued.
...
- 10.6k
48
votes
Do scientist who study martian geology typically use the term areology?
Good question. I work on the Curiosity team, and I hear "geology" all the time, but never "areology." Too bad, really, since it's a great word, and I love the R/G/B Mars series.
- 1,405
31
votes
Do other planets and moons share Earth’s mineral diversity?
We turn to Mars, which we have studied for decades now. And we do see plenty of mineral diversity on the surface of the Red Planet, it's not just rust by any means.
Curiosity's CheMin analyzer has ...
- 8,445
26
votes
Rock arches on the moon?
There's a saying, "ask 4 geologists about a geological feature and you'll get 5 or 6 answers, maybe more".
My interpretation of what you have highlighted is not a rock arch - an arched rock ...
- 13k
23
votes
Why is Curiosity not heading for Peace Vallis?
It is actually too likely to find water there. There are 3 categories of Planetary Protection missions for a mission to Mars, IVa, IVb, and IVc. Curiosity meets the IVa criteria, a mission not ...
- 121k
23
votes
Accepted
Do scientist who study martian geology typically use the term areology?
A search on arXiv for "areology" produces no results. A search on ADS produces two results (one of which has the subtitle "The Geological Environment of Mars"). So the term is ...
- 5,038
22
votes
Rock arches on the moon?
If it helps, following the citation trail leads to the back side of the same rock formation being visible on three other photographs on the same reel of film:
https://history.nasa.gov/alsj/a16/AS16-...
21
votes
Do other planets and moons share Earth’s mineral diversity?
They do not! The reasons for this are simple: minerals are semi-stable configurations of elements formed in certain pressure-temperature-redox conditions. A planet in the possession of active plate ...
- 10.6k
17
votes
Is there dirt or its structural equivalent on Mars?
The fine regolith on Mars is regarded as being the closest equivalent to an Earth like soil. It contains sand and dust. Clay deposits have been found. The two could be mixed to produce a more graded ...
- 13k
16
votes
How could InSight's seismometers be intentionally and meaningfully "pinged"?
The traditional method (as used in the Apollo project) was to crash used SIVB stages into the Moon.
- 126k
14
votes
Accepted
Were launchpads at KSC built with pilings or footings?
Based on this article, 39A is just concrete on top of sand. That does seem a little ridiculous though.
The pumps piled up another portion of the dredged sand on the launch pad, creating a flat-...
- 156
14
votes
Accepted
Difference between "mafic floor" and "olivine-bearing floor" in Jezero crater? (Perseverance landing site)
TL, DR: Olivine is a specific type of mafic or ultra-mafic mineral that is specifically identified in some parts of the overall mafic floor of the crater. The olivine is seen in specific areas of ...
- 8,445
13
votes
Why are there mountains/mounds in the centre of craters on the lunar surface?
It's actually a rebound effect that occurs with an impact forming a large crater. https://www.lpi.usra.edu/education/explore/shaping_the_planets/impact-cratering/ explains:
Central peaks – Peaks ...
- 8,445
13
votes
Why are there mountains/mounds in the centre of craters on the lunar surface?
It might help to compare the crater formation to a drop impact:
It seems that rock can behave like a viscous mass if you hit it fast enough.
- 1,678
12
votes
Accepted
Is there any reason Cyanobacteria or Lichens can't survive on Mars?
We don't really know. A study from 2012 suggests that lichens and cyanobacteria could indeed survive the "obvious" perils of Mars, including radiation, low pressure, and temperatures dropping as low ...
- 8,445
11
votes
Accepted
Why is the northeastern region of Syrtis Major Planum a selected landing site for the Mars 2020 mission?
Edit - added more detail on the specific geological interests per the question revision
Selection Process
This letter to Dr Michael Meyer, lead scientist for the Mars Exploration Program, gives a ...
- 9,976
11
votes
Which scientific articles together give proof of all the chemical elements found on Mars?
From Mars Fact Sheet:
hydrogen (H), carbon (C), nitrogen (N), oxygen (O), argon (Ar), neon (Ne), krypton (Kr), xenon (Xe).
From Inorganic analysis of martian surface samples at the viking landing ...
- 7,493
11
votes
Do scientist who study martian geology typically use the term areology?
It does not appear to be a term in common usage in formal scientific settings. Wikipedia suggests that geology is a term generalised to all planets and areology is mainly used in popular media and ...
- 744
10
votes
Would a circular saw on one arm and a trowel on another on the Mars 2020 rover add scientific value?
The rover already has a core drill for this purpose: it drills through the top layers and exposes the rock underneath. The big advantage of a drill over a shovel is that a drill can go through (most) ...
- 126k
9
votes
Constant lunar sub-surface temperature
tl;dr: The number is often given as 252 +/- 3 K (or about -21°C or -6°F), so @BowlOfRed pretty much nailed it using first principles!
Without atmosphere, equilibrium temperature at 1AU is about -17C. ...
- 149k
9
votes
Accepted
Is there really a frozen lake near the equator on Mars?
This paper reports SHARAD observations of this site, and also references previous publications based on an earlier radar instrument MARSIS. It's complicated and the data seems to be ambiguous, but the ...
- 19.4k
9
votes
What is the white stuff emerging from a hole on the surface of Mars?
That's almost certainly ChemCam's laser vaporizing some rock for its spectrometer. You can see similar white spots in this video:
The laser fires in short pulses 10 ...
- 10.7k
9
votes
Do other planets and moons share Earth’s mineral diversity?
According to this dated but enjoyable Scientific American article https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2020/01/Hazen-The-evolution-of-minerals-Scientific-American.pdf, Earth is ...
- 17.7k
8
votes
Why is Curiosity remaining on the Vera Rubin Ridge for so long?
There are several causes:
delays due to operational problems.
When I last left the rover back in September, it had just climbed onto Vera Rubin Ridge. Since then, it has slowly maneuvered ...
- 126k
8
votes
Accepted
Why does the Mars Global Surveyor carry a bit of the Zagami meteorite?
In case anyone doesn't know, and it's maybe not obvious from the question, this meteorite is believed to be a chunk of Mars that was knocked free by an impact a couple of million years ago.
The ...
- 19.4k
8
votes
What are the dark areas on the moon?
Wikipedia differentiates the compositions between the brighter highlands and darker maria on the Moon (citing Ref. 1):
The relatively low silica content suggests that all regions are composed ...
- 8,445
8
votes
How could InSight's seismometers be intentionally and meaningfully "pinged"?
Let's examine what's already on InSight:
A seismometer (SEIS). It's so sensitive that it is expected to be able to sense windstorms, dust devils, and the tidal forces of Mars' moon. To isolate the ...
- 47.7k
8
votes
Where exactly are those eight steep slopes on Mars revealing structures of buried ice?
Scarp #1:
According to this NASA information, this specific scarp is located at 56.6 degrees South latitude, 114.1 degrees East longitude. This picture was taken on May 7, 2011.
I went to Google ...
8
votes
Accepted
Significance of Venus surface photos
That's what I found so far.
In Abdrahimov, Basilevsky [2002] Venera photos are used for geological context interpretation comparing with orbital radar data.
quotes:
The photogeologic analysis shows ...
- 9,041
Only top scored, non community-wiki answers of a minimum length are eligible