Hot answers tagged

66

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. One note: while most of the papers you'll find are on our own geology, the moon isn't that different compositionally from Earth at all, so I'm assuming the ...


48

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.


28

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 studied the surface mineral composition of the Gale Crater. Quoting from this answer: This diagram provided by Curiosity's CheMin analyzer (source) shows that ...


23

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 hardly ever used in titles of scientific publications. From google scholar, there seems to be a few publications about LIBS that use the term. In conclusion, it ...


22

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 intended to seek life on Mars. A IVb mission looks for life, and a IVc enters a special region which is: A special region is a region classified by COSPAR where ...


17

They do not! The reasons for this are simple: minerals are semi-stable configurations of elements formed in certain pressure-temperature-chemical conditions. A planet in the possession of active plate tectonics will also be in the possession of more extreme pressures and temperatures (not to mention introduces chemicals to such conditions that would not ...


16

You are correct about some of the sources of moon quakes. NASA states there are are least four types of moon quakes: There are at least four different kinds of moonquakes: (1) deep moonquakes about 700 km below the surface, probably caused by tides; (2) vibrations from the impact of meteorites; (3) thermal quakes caused by the expansion of the frigid ...


16

The traditional method (as used in the Apollo project) was to crash used SIVB stages into the Moon.


13

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-topped pyramid of sand and shell 80 feet (24.4 meters) high. During the process, draglines, bulldozers and other earth-moving equipment molded the mound into the ...


12

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 formed in the central area of the floor of a large crater. For larger craters (typically a few tens of kilometers in diameter) the excavated crater becomes so ...


12

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.


11

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 synopsis of the assessments and findings at the February 2017 workshop. The workshop aimed to narrow the shortlist of landing site candidates from 8 to 3. Five ...


11

The dark and large areas are solidified lava beds from earlier periods of Lunar evolution, when it was still volcanically active. Notice that they might be somewhat less covered by still visible impact craters than on average the lighter areas are, as then still liquid lava would completely cover any traces of impacts from the early Lunar history. As the ...


11

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 as $-50°\text{C}$. In 2012 the Planetary Society reports a two-stage experiment performed at the German Aerospace Center, in which (1) organisms were ...


11

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 science fiction. "The geology of Mars is the scientific study of the surface, crust, and interior of the planet Mars. It emphasizes the composition, structure,...


10

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) rock types, whereas a shovel can only scrape off loose rubble. A shovel is an imprecise instrument: you run a straight edge over the soil. The depth of that ...


9

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 bottom line appears to be that it isn't a large lake of solid ice. It might be broken up volcanic rock with ice filling the spaces, or it might just be rock. ...


9

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 times a second, and there's gaps between the video frames captured by MAHLI. The two are not synchronized and only sometimes align, allowing MAHLI to see the ...


9

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 which the indicated "olivine-bearing floor" is most prominent. Mafic: More than just olivine In mineralogical terms, "mafic" is a more ...


9

These can be interpreted as desiccation cracks, filled with calcium- and/or magnesium sulfate (Ca-/Mg-SO4, seen as white material). Methods used, for brevity citing from the below pop science link: "... The team took a close physical and chemical look at those polygons using Curiosity's Mastcam, Mars Hand Lens Imager, ChemCam Laser Induced Breakdown ...


8

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 southish atop the ridge, encountering colorful rocks. Progress has occasionally been interrupted by various issues (uplink failures, arm faults, short drives, et ...


8

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 sensors from motions of the main body of InSight, SEIS is in its own pod that will be placed a few feet away by a robotic arm, and attached by an umbilical. ...


8

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 that the material of plains with wrinkle ridges (Pwr) dominates the Venera-9 landing-site ellipse (it occupies ~60% of the area of the ellipse). The material of ...


7

As far as I can tell, the 50 figure is somewhat erroneous/only approximate which is (understandably) caused by the confusing way the proposed landing site list changed during the selection process. I've attempted to collate the information from the Landing Site Workshops overview which has all the presentations and announcements from the entire process. In ...


7

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 story seems to be clear here. The scientist had bought (with his own money) a chunk of the meteorite to test his instrument (which presumably be observing some of ...


7

A strong candidate for largest river on Mars that I have found is the Kasei Valles region of Mars. According to the Wikipedia entry, this area is home to a geological feature similar to our famous Grand Canyon. . . except for one major difference. This guy is 300 miles wide at maximum instead of 18 miles. Source: Areong via Wikipedia, CC BY-SA 4.0 General ...


7

I suggest that the Valles Marineris–Chryse Planitia complex is the largest former Martian river system. Valles Marineris has many features that appear to have been created by water flow and the outflow channels leading from it to the former oceana,b,c,d,e,f in Chryse Planitia are clearly visible and bear many features in common with river systems on Earth. ...


7

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 sites: (DOI: 10.1126/science.194.4271.1283) silicon (Si), iron (Fe), magnesium (Mg), aluminum (Al), sulfur (S), calcium (Ca), titanium (Ti), strontium (Sr),...


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