[petuniasevan]

You'd still see it, but it would appear only 20% of the size of Earth's moon. Plus it is irregular in shape so its phases would appear strange. Its albedo is very low; Earth's moon reflects twice as much light. Still, it would be obvious even to a casual observer.

[BradyLS]

Thanks for the answer! Can anyone recall any SF stories set on Mars that evens mentions its moons in its sky?