[LibWhacker]

I wonder if the Sun looks larger on Mars’ horizon than it does when it’s not on the horizon, due to atmospheric distortion — similar to what we see on Earth when the Moon or Sun is on the horizon?

[Moonman62]

I wonder if the Sun looks larger on Mars’ horizon than it does when it’s not on the horizon, due to atmospheric distortion — similar to what we see on Earth when the Moon or Sun is on the horizon?

Moon Illusion

[steve86]

I believe that’s entirely an illusion (psycho-sensory distortion). Apparent size as you perceive it is bigger near the horizon but actual angle subtended is slightly less. There is no actual magnification at all. Still, it would be interesting to see if the illusion happens on Mars as well (will have to arrange a trip).

[dragnet2]

Phobos Passes in Front of Sun's Face, Nov. 9, 2010, as seen by Mars rover Spirit.

This is far above the horizon.