# Questions tagged [mars]

Questions regarding Mars, the fourth planet from the Sun.

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### What's Mars mass compared to Earth since there are many different figures around?

According to, phys.org it's mass is just 6.4185 x 10$^{23}$ kg, which is around 15% that of Earth's According to, Universe Today However, it’s mass is just 6.4185 x 10²³ kg, which is around 10.7% ...
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### What's the radius of Mars over Mount Olympus?

According to Mars mass compared to earth, the Equatorial radius of Mars is 3396.2 kms and the Polar radius is 3376.2 . But I want to know the radius of Mars over Mount Olympus and it wont be the same ...
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### Calculate ephemeris for Mars before 1600 in Stellarium

I am trying to calculate Mars' ephemeris for XVI century (specifically from 1570 to 1599). However, Stellarium only allows calculations beyond 1600. Is there optional package that I can install to ...
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### Is there any astronomical phenomenon such that its movement can be perceived in real time?

Note: I think I could make this question more interesting by asking, "What is the phenomenon at greatest distance from Earth such that its movement can be perceived in real time?" My ...
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### How soon after the accretion did Mars experience the magma-ocean stage?

ChatGPT told me this: "Mars likely experienced the magma-ocean stage very early in its history, shortly after its accretion around 4.6 billion years ago." This is hard to digest. The planet'...
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### Pyephem equivalent when living on Mars?

The python pyephem library is great... if you are on Earth. Has anyone built one if you were living on Mars? A search on this turns up the ephemeris of Mars many times, but not something that could ...
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### Could mars become volcanically active if it is pulled into a highly eccentric orbit

Let's suppose that a passing planetary mass object pulls mars into an even more eliptical solar orbit, not accounting for other planets, to what degree of eccentricity would be needed for, let's say ...
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### Why does Mars have a jagged light curve?

Caption: The following chart is the predicted light curve (visual magnitude as a function of time) of Mars, according to the most recent ephemeris data. Magnitude data is sampled with a 2 days ...
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### How did Herschel determine the diameter of Mars?

The book The Planet Mars: A History of Observation and Discovery by William Sheehan states that Herschel calculated the diameter of Mars to be 0.55 times that of the Earth, and he found its figure to ...
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### Which of the blocked radiation windows will (mostly) open if one where to observe from the surface of Mars, instead of the Earth?

Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some ...
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### Where is the vernal equinox of Mars located?

Dear Esteemed Astronomers, could you kindly advise how to find/derive the location of the Martian vernal equinox? Is it simply located at the cross product of Mars's north pole and the normal to Mars'...
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### What would be the doppler effect in the a 2.42GHz signal coming from a satellite in orbit around Mars, received on Earth ground station

Say there is a satellite in orbit around Mars, and it sends a signal at such a time that it is more or less behind the Sun. In that case, Mars would be "Occulted" by the Sun. That signal is ...
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### How will NASA perseverance re-enter the earth from Mars

Perseverance has been in Mars since 2021, and I'm just wondering the mechanism through with it will return to earth.
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### Is the level of carbon monoxide on Mars at an expected equilibrium level?

Is the level of carbon monoxide in the atmosphere of Mars (0.0747%) exactly what would be expected under equilibrium conditions given the ambient Martian atmospheric temperature, pressure and ...
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### Are the rotational axes of Earth and Mars parallel?

So I was stuck on a question involving the transformation of coordinates from geocentric to Mars-centric coordinates. The relative position of Mars and its orbital details are given. I thought that we ...
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### What is the concentration of molecular oxygen in the Martian atmosphere?

In the early 1970's and prior to the Viking landers, T. Owen measured the oxygen in the Martian atmosphere at 0.3%, I believe by doppler shift methodology through the Earth's atmosphere (wow). During ...
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### Which is brighter, Mars as seen from Earth, or Earth as seen from Mars?

At their closest flyby, Earth is ‘new’ and dim from Mars, and Mars is ‘full’ from Earth and brightest as seen from Earth. When Earth is 39 degrees from the Sun then Earth is brightest as seen from ...
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### Conditions on Earth when Mars was warmer, wetter & had a thicker atmosphere

To the question, What part of a star's habitable zone has the best chance of developing life?, I made the following comment: It's always intrigued me as to why some people have thought that life in ...
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### Trouble seeing Mars and Venus more than specks of light

Finally been breaking out the telescope to get a better look at things recently, and have been attempting to take advantage of Mars's and Venus's positions in the sky, but I haven't been able to see ...
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### Does Mars get hit by as many meteors as the Earth?

The Moon gets bombarded by meteors at the same rate as the Earth according to What the moon's craters reveal about earth's history Does Mars or any other planet get bombarded at the same rate as the ...
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### Mars crater nomenclature

The Wikipedia page for planetary nomenclature states that small craters don't follow the same rule as large craters as far . What is the cutoff between small and large craters (as far as naming is ...
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### How could we detect if Venus or mars were being terraformed by aliens? [closed]

If any other body in our solar system was being terraformed by aliens, what would be the ways in which we would detect this? Initially I thought of Venus or mars but I guess this could extend to any ...
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### Distance from Earth to Mars at time of November 8, 2022 lunar eclipse maximum

I’m looking for the “exact” distance from the Earth to Mars, at the moment of the lunar eclipse maximum earlier this week (November 8, 2022). As many significant digits as you can muster. Between the ...
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### How do we know that ice from the S1094b event was from Mars surface and not from the impactor?

The recent news story NASA’s InSight Lander Detects Stunning Meteoroid Impact on Mars, about an impact that occurred on Mars on December 24, 2021 (event S1094b), shows a picture of the impact crater, ...
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### What is the elevation of this mesa in Noctis Labyrinthus?

I'm interested in the elevation of this mesa in Noctis Labyrinthus. It's located at -6.3, 265. This image is from https://www.geo.fu-berlin.de/en/geol/fachrichtungen/planet/press/archiv2016/...
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### How could Mars' atmosphere be shed by solar winds, when Venus has a thick atmosphere despite no magnetic field?

Our current understanding of how Mars lost its atmosphere is because it lost it magnetic field, due to a barrage of reasons, such as core cooling due to low volume and cooling off quickly. This ...
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### If 16 million kilometers were added to Earth's semi-major axis, what measurable effect would there be on Mars' orbit?

I have some education in astronomy, but nothing extensive in astrophysics. I can follow mathematical procedure with assistance. Procedural responses are most welcome!
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### Are the human-made devices on Mars searching for existing life?

According to the answers to my other question - Most powerful microscope on Mars? The microscopes on Mars do not search for life. SHERLOC (Scanning Habitable Environments with Raman & Luminescence ...
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### Would an accumulation of dust in a planet's L1 Lagrange point plausibly obscure it from Earth?

I'm designing a hypothetical newly discovered planet in our solar system that has an ecosystem comparable to Earth's that supports intelligent life. The explanation given for the planet remaining ...
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### When were Swift and Voltaire discovered?

Deimos -- Mars' smallest moon -- has only two named features: the Swift crater and the Voltaire crater. Based on the Gazetteer of Planetary Nomenclature, their names were approved in 1973. Given the ...
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### Most powerful microscope on Mars?

From all the missions sent to the surface of Mars, do any of them have a microscope? If yes, then which one has the most powerful microscope? Is it capable of detecting microbes?
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### Which is closer to the Earth, Phobos, Deimos or Mars? [closed]

Which one is closer to the Earth, Phobos, Deimos or Mars? None of the answers that I find actually answer my question.
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### How new is this crater?

I've been looking at HiRISE images, and this description says that this crater is new, which is why we can see the bright ejecta. How long does it typically take for the bright ejecta to erode away? ...
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### On Mars, why are the seasons "strongly amplified" in the southern hemisphere and masked in the northern hemisphere?

In the Darian calendar entry on Wikipedia we read (emphasis mine): The Martian year is treated as beginning near the equinox marking spring in the northern hemisphere of the planet. Mars currently ...
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### Salinity of Martian water 3.5 Billion years ago

Was Mars' ocean 3.5 billion years ago salt water or fresh water? On a related note: would we be able to drink the water that is on Europa?
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### Earth-Mars-Moon or No Moon Barycenter Orbit Possible?

Could an object of sufficient mass deflect Mars so that it ends up stably orbiting an Earth-Mars-Moon barycenter? What would the distances eventually become between each orbiting body? What if the ...
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### Gamma Ray Spectroscopy in detecting hydrogen

My professor explained saying that bombarding the surface with cosmic rays breaks off a few neutrons from nuclei and the nucleus, having undergone a change in energy level, emits a gamma photon. The ...
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### Longest line of sight on Mars

It is said that the slope of Olympus Mons is so gradual that the peak cannot be seen from the plain; it is hidden by the planet's curvature. That provokes questions: How steep is the steepest of the ...
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### Could the timing of the oxygen spike on Mars be used to determine if photosynthesis is responsible?

I am wondering if the timing of the oxygen spike on Mars could be used to determine if photosynthesis is the source (which would be another indication of life on Mars), or if it is purely heat related?...
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### When will Jezero crater on Mars reach its lowest atmospheric pressure and what pressure will that be?

In the first sols of the Mars 2020 mission the local pressure was something above 750 Pa. It has been decaying since then and is now less than 650 Pa, this is what required Ingenuity's rotorblades to ...
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### Is it more accurate to measure distances from Mars?

I'm trying to figure out answer to this task: At a certain level of development of the Martian civilization, scientists of this planet began to measure distances. Will their measurements be more or ...
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### How would the surface of Mars compare with the Atacama desert for millimeter wave (and shorter) radio astronomy?

In this answer to What kind of experiments would a scientist do on Mars? I suggest that the resemblance of the ALMA array's site in the Atacama Desert to the surface of Mars suggests millimeter ...
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### Mars satellite data similar to Sentinel-2?

For Earth, there is lot of free satellite data easily available. For example, I can download the Sentinel-2 optical images freely from https://scihub.copernicus.eu/. What would be the closest thing ...
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### How exactly was Giovanni Cassini able to measure the distance to Mars?

Recently learned that Cassini was able to calculate the distance to Mars quite well using parallax in 1672. I was surprised, since even at opposition of Mars, the parallax (with respect to the Earth's ...
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### Why are all the ejecta blankets in the same direction in this image?

I was browsing the HiRISE images and found this one In this image, there are several craters with an ejecta blanket that is to the left of the crater. How did all the ejecta blankets end up on the ...
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### Are there any SuperCam spectra available?

A lot of pictures from the SuperCam, the NavCam or the Mastcam onboard the Perseverance rover are available online (for instance on the NASA and JPL websites). Have any SuperCam spectra been made ...
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### What is the maximum speed in which a human jumping away from Deimos and towards Mars would actually fall back down rather than enter Mars' gravity?

Imagine a universe in which Deimos and a human are the only objects in the universe. It doesn't matter if the human jumped even 1 nanometer per second slower than escape velocity, they would still ...
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### Mars Ecliptic Latitude

It's stated Mars orbital plane is 1.8 degree to the ecliptic. How then can Mars can ecliptic latitude went beyond 1.8 ? Example; Jan 8th 2023, Mars latitude at +2.8. 24th Jan 2025, +4.3. Isn't the ...