What will shooting stars look like on Mars?

Question

I'm wondering what the martian night sky will be like.

Since the atmosphere is so much less dense than that of Earth's, will we see shooting stars in the same way? Or will they tend to burn up much closer to the ground and therefore be dazzlingly bright and spectacular?

Companion question in Astronomy SE: How will planets behave in the night sky as seen by Mars colonists? — uhoh, May 04 '18 at 06:55

Tom Spilker · Accepted Answer · 2018-05-04T20:49:36.047

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Although the Martian atmosphere is much less dense at the surface than Earth's, the altitude where meteors start to glow, ~80 km at Mars (see https://en.wikipedia.org/wiki/Atmospheric_entry , and @Mark Adler calculated it as well), is not hugely different from that at Earth, where it is ~100-110 km. They would appear to be moving ~20-30% faster than at Earth because they're closer, but otherwise would look very much like what we see at Earth. Earth's larger mass would accelerate the incoming meteors more than at Mars, but for most meteors that doesn't make a lot of difference: their V∞ of approach is so high that the added GM/r energy is considerably smaller than their approach energy.

edited May 04 '18 at 20:49

answered May 04 '18 at 17:29

Tom Spilker

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Can you give a source for this? How do you know this is true? The stuff about Earth accelerating meteors is very suspicious; while there would be a small effect, it's very small compared to the velocity of these objects before they approach earth. – uhoh May 04 '18 at 19:54
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The velocity at the entry interface of an object on hyperbolic approach with a given V∞ is Vi = SQRT[ V∞^2 + 2GM/ri], M = mass of Earth and ri = planetocentric radius of the interface point. If V∞ is zero, this is just the escape velocity from that altitude, ~11.1 km/s. If the incoming object is, say, a Perseid meteor with a V∞ of about 60 km/s, then the GM/ri term is indeed very small compared to V∞^2. But some meteors are like near-Earth asteroids: low V∞, a few even less than 1 km/s. In those cases most of their energy is from Earth's gravitational acceleration. – Tom Spilker May 04 '18 at 21:03
Thanks for adding the link! It's a good practice to always include sources when basing answers on facts and figures in Stack Exchange. Discussion of relative velocity of meteors has really piqued my interest now, I'll do some more reading. I've always thought that most visible meteors are produced by particles in eccentric heliocentric orbits similar to comets rather than traveling in orbits similar to Earth's, but now I'm going to have to look into this further. – uhoh May 05 '18 at 03:31
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Indeed the majority of meteors we see are in eccentric orbits so their V∞ of approach is pretty high. I saw one source saying the average is ~20 km/s, which means Earth's gravity only accelerates them by ~1.5 km/s before entry. The slow ones are probably pieces shed from NEAs, Near-Earth Asteroids. There will be similar ones at Mars (Near-Mars Asteroids? the IAU hasn't added that category yet!), but the eccentric ones will dominate there as well. – Tom Spilker May 05 '18 at 03:42

score 2 · Answer 2 · edited May 05 '18 at 04:10

disclaimer: uhoh asked me to copy/paste this from my answer on a different question.

The page Martian Meteor Showers repeats a claim that the altitude for, and magnitude of, meteors on Mars are roughly the same as Earth's:

A 1996 paper in the journal Icarus by Adolfsson, Gustafson and Murray has pointed out that, although the atmospheric pressure at the surface is less than one percent the respective value at the Earth, the larger mean scale height of the atmosphere means that at an altitude of ~120km where meteoroids begin to ablate, atmospheric densities are comparable. As a result, meteors of the same mass and atmospheric entry speed at the atmospheres would be of similar magnitude . Taking into account the slower average speed of incoming material at the heliocentric distance of Mars from the Sun, a meteoroid of the same mass entering the martian atmosphere at 30km/sec would produce a meteor +0.5 mag fainter than at Earth.

Adolfsson, Gustafson and Murray, The Martian Atmosphere as a Meteoroid Detector Icarus, Volume 119, Issue 1, January 1996, Pages 144-152, https://doi.org/10.1006/icar.1996.0007

What will shooting stars look like on Mars?

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