Arabia Terra in the northern highlands of Mars

Bright and dark slope streaks on the surface of Arabia Terra in the northern highlands of Mars.

The heavily cratered and eroded surface identifies it as one of Mars's oldest features.

Streaks on some Martian slopes have been associated with underground water that thaws and flows in the Martian summer and contracts and freezes in the winter.

The streaks here formed another way—likely through dust deposited and cleared away by the planet's ever-shifting winds.