Mars horizon

[zaraza]

Take a look at this picture:
http://apod.nasa.gov/apod/ap101201.html

Horizont doesn't looks flat, it's wavy.
Is it photography/lenses artifact or Mars feature itself?

[Romanus]

Certainly an artifact--though I know little about the subject, it may be due to tracking the satellite over the length of the exposure.

It's a neat photo, anyway, one of the few that shows the enormous albedo contrast between the two bodies.

[slang]

Take a look at this picture:
http://apod.nasa.gov/apod/ap101201.html

Horizont doesn't looks flat, it's wavy.
Is it photography/lenses artifact or Mars feature itself?

APOD refers to the Unmanned Spaceflight forum, where someone asked the same question. The answer there is that it was caused by

A slight rocking of the spacecraft during the scan. If it had just rotated to take this off-nadir view the long booms might not have settled down yet.

This Planetary Society blog entry explains more about the image.