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Here on Earth we are blessed with being able to see some other planets, Mars & Venus etc, with the naked eye on a fairly regular basis thanks to the distance between the planets.

What about from Mars? What planets would be visible to the naked eye on a regular basis from Mars?

Earth would obviously be one of them, as we can see it, but are any other planets close enough to mars at any point to be visible?

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2 Answers 2

up vote 3 down vote accepted

Aside from having Earth visible in the night sky instead of Mars, you would expect the same planets to be visible.

  • Venus will appear as a bright star close to the sun - smaller than we see it, but still very bright.
  • Jupiter and Saturn will be easier to see in the night sky, and it should be possible to pick out Jupiter's four major moons with the naked eye.
  • Uranus is going to be interesting. while Mars will get closer to it than Earth, as Rob points out, the dust in the MArtian atmosphere will remove the possibility of seeing Uranus.
  • Neptune will still be invisible to the naked eye.
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I take it you mean jupiters moons? interesting that those would be able to be seen, i bet that would be interesting, can we see none of those from earth? –  RhysW May 10 '13 at 9:46
    
Doh - yes, moons:-) and yes, you can see them with the naked eye from earth - a few astronomers have reported sighting Callisto and Ganymede. Io and Europa are masked by Jupiter's glare. –  Rory Alsop May 10 '13 at 9:50
    
And that glare is significantly reduced enough from mars to not 'hide' Io and Europa? That's pretty interesting. Thankyou, –  RhysW May 10 '13 at 9:53
    
You can actually see Europa from earth if you block out Jupiter with something. Tricky, but apparently doable - I haven't managed it, but have seen all four moons easily with cheap binoculars. –  Rory Alsop May 10 '13 at 9:55
    
Hmm. A calculation of visual magnitudes is required for my upvote (though I think you're most likely correct). Mercury would be a problem though. –  Rob Jeffries Aug 2 at 4:54

You will see Earth, Venus, JupiTer, Saturn. TheY are either bright enough, or come closer to Mars than Earth, that there are no complications/calculations necessary.

Uranus is just a naked eye object from Earth (magnitude 5.3-5.9). Its closest approach to Earth, when it is brightest is 17.2 au distant. Mars' orbit takes it closer by about 0.5 au, so you might have thought it would be more visible. But no - on average the visual extinction in the dusty atmosphere of Mars is around 0.5-1 astronomical magnitudes (see this relevant Astronomy SE answer) and this means the gain due to proximity (about 0.1 mag) is wiped out by the extinction. You would be very unlikely to see Uranus unless you had exceptional vision and knew where to look when Uranus was at its brightest.

Mercury is tricky. It is certainly bright enough to be seen from Mars, but would be sepated by a smaller angular distance from the Sun. The contrast between Sun and Mercury would be the same. I think on balance, it would be visible if you looked carefully, since Mercury can be seen from Earth when it is closer to the Sun than its maximum angular distance, though the Martian atmosphere might affect the glare from the Sun differently.

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Good answer. I like it. Thanks for the Uranus info - I'll update. –  Rory Alsop Aug 6 at 9:13
    
I wonder if proximity pushes Ceres into the visible range. –  Chris White Aug 6 at 9:47

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