Questions tagged [mars]

Questions regarding Mars, the fourth planet from the Sun.

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44
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3answers
10k views

Why is Mars cold?

The surface temperatures of Mars are about -87C to 5C, which is much colder than that of Earth's. If Mars has 95% carbon dioxide, which is a Greenhouse gas, why is the surface of Mars so cold? ...
31
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2answers
2k views

Could any known, living organisms on Earth survive on Mars?

No life has been discovered outside of Earth (yet?), but do we know if anything that would be considered "living" on Earth could conquer Mars? (or maybe Venus?) With the Mars One project on the way, ...
23
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2answers
5k views

What detail can Hubble see on Mars?

I'm researching a scene for a sci-fi novel in which the near-future protagonists observe earth through a station-mounted telescope in Mars orbit. My goal is to understand how much detail they ...
20
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2answers
4k views

How did Mars come to have a 24 hour 39 minute day?

Mercury rotates three times for every two revolutions around the Sun, apparently due to a gravitational resonance with the Sun.Venus takes about 225 days to rotate, and rotates in the opposite ...
20
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1answer
859 views

Why Did Mars lose its Magnetic Field?

I had heard that Mars once had a planetary magnetic field, but that it is now gone? What happened to it?
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2answers
1k views

Whats the probability of a hazardous impact for human life on Mars?

Yesterday my sister and I have discussed the recent efforts of SpaceX to create a permanent colony on mars. When coming to the several dangers of creating a habitat on a different planet, we got ...
17
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4answers
4k views

Is the Earth going to evolve towards Mars' fate or Venus' fate?

Upon reading on this site (and many others), one can think that Mars might have supported life in a distant past (discovery of liquid water, valleys, mountains...). On the other hand, Venus is the ...
16
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1answer
151 views

Loss of atmosphere on Mars

If the atmosphere on Mars was once much thicker, how was it likely lost? Was it due to interaction with the solar wind, the small size of the planet, both, or something else, and approximately how ...
15
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4answers
13k views

If Venus and Mars changed places, would we then have 3 habitable planets?

This is the supposition: Venus is too hot, Mars is too cold. If they switched places then Solar energy would change to make both more Earth like. We might as well have had three instead of just one "...
14
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1answer
930 views

Martian Constellations

I was wondering if the constellations visible from Earth would also be visible from Mars. Would they look the same but just shifted slightly in the sky due to the larger circumference of the orbit?
14
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2answers
360 views

What earth organisms would survive if they arrived on Mars?

Contaminating other planets is a concern in space exploration. My question is what organisms, or small collections of organisms, from earth would be able form a self-sustaining population on Mars? I'm ...
13
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1answer
500 views

At Mars' equator how long does twilight last?

With Mars' thinner atmosphere I'm assuming twilight would not last as long compared to the duration on Earth. Has there been any determination of the length of twilight on Mars at the equator or any ...
13
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4answers
904 views

If we found evidence of life on Mars, how would we know that it originated on Mars rather than Earth?

Consider this scenario. One of the probes sent to Mars either very soon, or within the next century, finds conclusive micro-fossil evidence that life once existed on Mars. One theory today that is ...
13
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1answer
492 views

Where did Mars 'water go?

Many sources indicate that there is ice water on Mars today, but it is mainly traces, here and there, but not that much. However, solid hypothesis state that there were oceans on Mars, see Wikipedia'...
12
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1answer
315 views

How would astronomical seeing on Mars differ from that on Earth?

Astronomical seeing is the limiting factor for the resolution of all but the smallest Earthbound telescopes. Source Stunning advances in adaptive optics (along with it's predecessor speckle ...
11
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2answers
164 views

Are there Earth rocks on Mars?

Certain meteorites found on Earth have been established to come from Mars: a giant impact ejected rocks from Mars, these rocks traveled through interplanetary space, and went through the Earth's ...
11
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3answers
1k views

Can Liquid Water exist on Mars?

Outside of a specially crafts environment, could liquid water exist on Mars? Not some time in the distant past, but within the last few years. Mars' atmosphere is too thin for water to exist, right? ...
11
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2answers
294 views

Does the Moon Have Enough Water for Robert Zubrin's Mars settlement Plan To Work?

In Robert Zubrin's "The Case for Mars" he outlines a plan to settle Mars by(among other things) finding water and using electrolysis to break up water into Hydrogen and Oxygen. This provides fuel for ...
11
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2answers
613 views

Why does Mars appear to retreat across the sky?

If you plot the movement of Mars across the Earth's sky it appears to move back on itself during its orbit. Why does it appear to have a loop shape from Earth?
11
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1answer
1k views

Are there large underground caverns on Mars?

Scientists talk about the possibility of life underground on Mars, and I assume they are talking about microscopic life that can live in small gaps in the soil or rock. But is there any evidence that ...
9
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3answers
2k views

Does Mars contain more iron than the Earth?

Is the reason Mars is red because its surface contains a lot of iron? (When dirt is red on Earth, it is sometimes caused by a high amount of iron). If so, does Mars contain more iron than the earth?
9
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1answer
436 views

Sunsets: Mars/Earth

I understand why our sky is blue and turns red when the sun sets or rises. I know why the sky on mars is red, but why does it turn blue during sunsets and rises? Shouldn't this actually not work due ...
9
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2answers
647 views

Why is Mars considered the outer edge of the “goldilocks zone”?

In both books and documentaries I often see the Goldilocks Zone as described between Venus and Mars with the Earth "just right." This seems sort of ill thought out to me, because it assumes that Venus'...
9
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2answers
228 views

How were the designations of “North” and “South” applied to the hemispheres of Mars?

How was it decided which hemisphere was North and which hemisphere was South on Mars? Clearly, the designations "North" and "South" apply only to the hemispheres which contain the axis of rotation at ...
9
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2answers
517 views

How easy would be to see the Moon from Mars?

This question arises from "What planet is better than earth to infer solar system configuration?", where one of the answers pointed that it's easier to discover the Moon from Mars than discovering the ...
9
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1answer
705 views

How do scientists know that a rock found on Earth came from Mars?

There are many documented cases of meteorites being reported as from Mars. http://en.wikipedia.org/wiki/Allan_Hills_84001 While I can understand that it's possible to know if a rock originated as a ...
9
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4answers
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Where to obtain Tycho Brahe's data?

I would like to obtain Tycho Brahe's data on Mars. What would be an authoritative source? One source I could find is this page (the data is given as an Excel file) but I have no idea can that be ...
9
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1answer
188 views

What could be the possible origin of boron found in the Martian soil if not from ancient groundwater?

In a recent observation reported in the ScienceAlert article 'Boron has been detected on Mars for the first time" reporting that The Curiosity rover has found boron on the surface of Mars, ...
9
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1answer
174 views

What is the cause of the variation from high and low mean obliquity periods of Mars?

It is reasonably well known that Mars has a greater obliquity range than Earth, due to Mars lacking a stabilising influence of a large moon. However, the Martian obliquity seems to have gone through ...
8
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2answers
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Is the curvature of Mars visible from the top of Olympus Mons?

Would you be able to see the curvature of Mars from the top of Olympus Mons? And how much curvature would you see if it was visible, would it be only barely detectable, or would you see a lot of ...
8
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1answer
1k views

How did ancient astronomers know to order the planets from the closest to the farthest from the Sun?

If we assume a geocentric model of the universe (like ancient astronomers did) how could we ever find out (again, like ancient astronomers did) the right distances of the planets? For example, how did ...
8
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1answer
514 views

Asteroids between Mars and Jupiter

Is the cluster of asteroids between Mars and Jupiter two dimensional as seen in every model of solar system shown in books or television? Or is it three dimensional as i think it should be?
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2answers
2k views

Selecting a Telescope for Viewing Planets

I hope to observe planets like Jupiter and Saturn, and moons. I am a novice when it comes to telescopes and I know images in magazines are not taken with at least 12-inch telescope in a middle of ...
8
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2answers
282 views

Why is ice on Mars not covered in dust?

There's exposed water ice on Mars, like in craters like this At the same time, Mars has dust storm, covering the solar panels of rovers, and occasionally covering the entire planet So why is this ...
7
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1answer
486 views

Are Tharsis Montes and Hellas Basin a result of the same event?

Looking at Mars map: the highest, biggest mountains and their associated highlands are essentially antipodes of the deepest, huge basin. Roughly 180 degrees away, similar latitude except opposite ...
7
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1answer
748 views

Mars night sky - how many stars visible?

How would the night sky look like from the Martian surface? Would there be more stars visible or less (compared to Earth)? Would they appear brighter/dimmer/same?
7
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3answers
162 views

Is Mars brightest from Earth at opposition, perihelion or somewhere in between?

After reading this article, I was inspired to run some simulations at NASA's JPL Solar System Simulator to see Earth's and Mars' orbits from above. From what I could visually determine (from the JPEG ...
7
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1answer
477 views

As viewed from Mars, what are Jupiter's and Saturn's maximum brightness in apparent magnitude?

From Earth, Jupiter's maximum brightness is -2.94 and Saturn's is -0.24. But what about from Mars? They should be brighter, but by how much? There are equations at the obvious wiki entry but I'm not ...
7
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2answers
321 views

How will planets behave in the night sky as seen by Mars colonists?

Certainly among the first colonists on Mars there will be a few people interested in Astronomy enough to enjoy the night sky. For them, familliar Mars will be missing and there will be a new, ...
7
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0answers
184 views

Is the wind's intensity on Mars similar to Earth?

I've read that in Mars' poles, the winds can be as fast as 400 km/h, when the poles are exposed to sunlight because the frozen $CO_2$ sublimes. I know that the Martian atmosphere is much thinner than ...
6
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1answer
433 views

Strange square-like formation on Mars

Recently I've explored an area on Mars' surface which one looks like huge hatch cap & hole, about 10 kilometers, between tons of circular craters. The formation is very unique and strange to me. ...
6
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2answers
2k views

Can we find rocks from Venus or Mercury on Earth?

As we know, we can find rocks from Mars on Earth, how about Venus and Mercury? Is that not found yet? Or it is impossible to find them because they are closer to the Sun, and debris won't go far away ...
6
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1answer
101 views

Why do transits of Earth across the Sun seen from Mars follow a pattern of occurring after 26, 79 then 100 years?

According to this answer transits of Earth across the disk of the Sun as seen from Mars: The (Arthur C.) Clarke story is quite correct. Earth (and Moon) would transit the sun from the viewpoint of ...
6
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2answers
217 views

Are meteors visible on Mars?

If a person were standing on the surface of Mars, under ideal viewing conditions for seeing a meteor: no clouds, the sun has long set, would a meteor be visible to the naked eye considering how thin ...
6
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1answer
244 views

If the Mars polar caps were melted, how deep would the oceans be?

If the Martian polar ice caps melted, given a surface temperature and pressure that allow for liquid water, how large would the oceans be? Would they match their ancient glory, or would they be ...
6
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1answer
2k views

At what depth on Mars would the atmosphere have equal pressure of that on Earth?

I know the atmospheric pressure on Mars is less than that of Earth, and so is its gravity. However, I know that the deeper you go (e.g. in a cave or a hole that is dug), the more atmospheric pressure ...
6
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2answers
4k views

If a person were to die on the Moon or Mars, would the body decompose?

There wouldn't be enough oxygen for any bacteria to decompose the body, right? Not to mention, the radiation of space might kill off most organisms on it. So would it decompose, given millions of ...
6
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2answers
230 views

How did the Mars satellites “take cover” from the recent comet flyby?

After comet Sliding Spring's Oct. 19, 2014 close flyby of Mars, NASA reports that All three NASA orbiters around Mars confirmed their healthy status Sunday after each took shelter behind Mars ...
6
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1answer
158 views

How deep in Mars would a person not need insulation and pressure? [duplicate]

How deep in Mars' surface would one have to go to both not need a pressurized suit and be warm enough to just wear clothes? in other words is there a dept Goldilocks where you would only need an ...
6
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1answer
226 views

Mars vs Venus: the retention of atmospheres in relationship to Earth

Correct me if I'm wrong, but the factors than enable a planet to retain or lose an atmosphere seem to be: 1. Magnetic Field, 2. Solar Winds, 3.Weight of Gases, 4. Planetary Temperatures. 5. Distance ...