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50 votes
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Why is Olympus Mons the largest volcano in the whole solar system?

This is mostly due to the fact that Mars does not have plate tectonics. Therefore the plate stays above the hotspot without moving, allowing magma to rise and pile up at the same place for millions ...
Jean-Marie Prival's user avatar
13 votes
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Water on Mars and Earth

If water on Earth came from meteorites, why doesn't Mars have substantial water? First off, that's a conjecture regarding the origin of the Earth's water rather than a known fact. A few times a year ...
David Hammen's user avatar
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10 votes

Carbon dioxide on Mars, Venus and Earth

Firstly, Mars is farther away from the sun than Venus or Earth, so it gets less heat from the sun. Secondly, Venus & Earth are volcanically active, whereas Mars is volcanically inert. Thirdly, the ...
Fred's user avatar
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9 votes

Why is Olympus Mons the largest volcano in the whole solar system?

The other answer is already pretty good: No plate tectonics and no water erosion allows material to pile up in one place, and then stay put. Neither is the case on earth: The plate moves away from the ...
Wolfgang Bangerth's user avatar
8 votes
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Strange circular structures found on a photo from Mars rover Curiosity at Dingo Gap

There are no circles, it is an image artifact. Here is another picture from Dingo Gap that shows nothing at the exact same position. Your mind is a well-trained pattern-matching machine that makes ...
Jan Doggen's user avatar
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7 votes
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What are Ordovican trace fossils, and what do they look like?

Trace fossils are marks or things left behind by living things do their thing, they are indirect remains of organisms, coprolites (poop), footprints, egg shells, ect. If we found a fossilized beehive ...
John's user avatar
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7 votes
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What is serpentinization, in the context of disappearance of surface water on Mars?

does serpentinization just refer to the formation of some hydrated minerals that happen to be of a class that is historically been referred to as serpentinite or it's subgroup Yes. In simple terms, ...
Gimelist's user avatar
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6 votes

What could be causing microseisms on Mars?

I think that the mechanism suggested in the article fits the bill the best: On Earth, microseisms are ubiquitous, caused largely by the sloshing of the ocean by storms and tides. Mars, despite ...
Erik's user avatar
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6 votes
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Composition of Martian Crust

The most abundant elements on Earth are: ...
Earth Science Expatriate's user avatar
5 votes

What is serpentinization, in the context of disappearance of surface water on Mars?

Serpentinization is a system of, chemical reactions which convert anhydrous ferromagnesian silicate minerals (pyroxene, olivine) into hydrous silicate minerals (serpentine) plus some other ...
Fred's user avatar
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5 votes

Water on Mars and Earth

Mars did have a significant amount of water (and atmosphere) early in its history. According to NASA, there was enough to form an ocean covering about half its surface: https://www.nasa.gov/press/...
jamesqf's user avatar
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5 votes
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What do the little flags on these martian wind speed data points mean?

They indicate wind direction (given by the long line or "barb") and speed (given by the shorter flags extending from each barb). In the same linked page you can read: The barbs extending from each ...
Camilo Rada's user avatar
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4 votes
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What could be causing microseisms on Mars?

In addition to @Erik answer, rocks as any other material dilates when it gets hotter and contracts as it gets colder. On Earth's such phenomena, and differences in temperature within rocks leads even ...
Camilo Rada's user avatar
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4 votes

Composition of Martian Crust

Although the Martian crust has a similar set of the most-abundant elements as Earth's -- for instance, on both planets oxygen is #1 and silicon #2 -- there are some differences. Compared with Earth's ...
Oscar Lanzi's user avatar
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4 votes
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How long would it take for Mars to cool after asteroid impact?

It would be interesting to read peer reviewed scientific papers that discuss the feasibility of "restarting Mars' core" via an asteroid impact. Some links would be appreciated. I am very sceptical ...
Fred's user avatar
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3 votes

Considering the thin piece of material on the surface of Mars in the image below, is there anything like it on Earth?

What you can see in the bottom picture is sandstone/mudstone/claystone. If you look at the bottom picture top right you can see a thin rock that has split off, this is how a rock splits after it has ...
trond hansen's user avatar
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3 votes

Thickening Mars's Atmosphere

We are already knowledgeable about some aspects of the requirements needed to terraform Mars & the Moon. As @David_Garcia_Bodego mentions in his comments, gravity is a major factor in celestial ...
Fred's user avatar
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3 votes

How to make Martian soil

Just as there are many different rocks and soils on Earth, so there are many different rocks and soils on Mars. To reproduce a Martian soil, you need to bear two things in mind. Firstly it should have ...
Michael Walsby's user avatar
3 votes

What are the most similar Earth analogues to Mars' seasonally recurring slope linea?

Analogues to Mars Recurring Slope Linea (RSL) is a current study topic in Antarctica (Dry Valleys). On Earth, analogues are known as water tracks, which are linear zones of higher moisture along ...
marsisalie's user avatar
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3 votes
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Possible and probable source of Curiosity Rover's $\small\sf{CH_4}$ detection on Mars

The possible source of methane is biological, and that is what everyone is hoping for, but the more likely source is geological, produced by chemical reactions between rock and water deep underground ...
Michael Walsby's user avatar
2 votes

Carbon dioxide on Mars, Venus and Earth

In addition to what has been said by @Fred, I'd like to add that CO2 doesn't actually generate heat, it is just very good at trapping heat. Mars doesn't get as much heat as Earth, and it also doesn't ...
TonyC's user avatar
  • 207
2 votes

How large were Mars' ocean tides and to what extent could they keep the oceans mixing and tend to keep salinity uniform? Has this been modeled?

I will attempt a partial answer. A search of Web of Knowledge finds that most of the papers addressing Martian tides either focus on atmospheric tides and their role in Martian weather or what current ...
jeffronicus's user avatar
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2 votes
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Is there really precipitation on Mars? Does frost count?

See this answer. Actually already snows on Mars. The snow, made of carbon dioxide, has been observed and studied by orbiting spacecraft. Aside from the different chemical composition from the stuff ...
Oscar Lanzi's user avatar
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2 votes

Considering the thin piece of material on the surface of Mars in the image below, is there anything like it on Earth?

If you enlarge the picture and follow a line at 1 o'clock from the weirdly shaped piece in question, a few feet away from it at the back of an imaginary 'man's head' rock, you will see a similar ...
Michael Walsby's user avatar
2 votes

Do any spike-like "cemented fillings of ancient fractures in a sedimentary rock", remotely similar to this one on Mars, occur on Earth?

Something that comes close are The Pinnacles, near Cervantes in Western Australia. The Pinnacles are a field of rock pillars up to 3.5 m tall. There are three theories for the formation of the ...
Fred's user avatar
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2 votes

Terraforming and maintaining a habitable atmosphere on Mars

It depends on what gases one wants the atmosphere to contain. Mars has a lower gravitational acceleration than Earth, mainly due to is smaller size. This lower level of gravity, combined with the ...
Fred's user avatar
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