November 13, 2013

Boulders on high

A piece of Mars: Right at the edge of the largest volcano on Mars (Olympus Mons) is a steep cliff. Here, near that edge, are some car-sized boulders poking out from a thick blanket of dust. Strong winds blow down […]
October 25, 2013

Are you being oblique?

A piece of Mars: Barchan, or crescent dunes, are generally thought to form from winds blowing from a single direction. Reality isn’t usually that nice. Here are two barchans with crescent-shaped slip faces on their eastern (right) sides, indicating that […]
October 11, 2013

Relentless wind

A piece of Mars: This is what the relentless work of the wind can do. That vaguely circular structure in the center of the image is probably the remains of a ~150 m diameter impact crater. Since it formed, it’s […]
September 30, 2013

Waiting for spring

A piece of Mars: These sharp-tipped hills are dunes near the north pole of Mars. At the height of summer they’re lovely dark dunes, but because it’s just barely spring here they’re still covered in white frost (mostly CO2 ice, […]
September 23, 2013

Yeah, it was that kind of morning.

The new favorite is “A Bushel and a Peck”. The first half dozen times it was cute. No, really.
September 18, 2013

How sand forms on Mars

A piece of Mars: All that sand on Mars — where does it come from? It’s often hard to figure that out. Here is a rare case where we can see material shedding from a stack of bright layered rocks, […]
September 4, 2013

Martian sports

A piece of Mars: In the center are two dark dunes, racing one another to jump over hurdles formed of older, now inactive dunes (or maybe those bright things are ripples, we still don’t know for sure). The dune in […]
August 29, 2013

What the wind brings, the wind takes away

A piece of Mars: These C and S-shaped things were once dunes that marched across the scene (from upper left to lower right), formed from sand deposited by the wind. Then that sand somehow became cemented, locking the dunes in […]
August 21, 2013

Natural modern art on Mars

A piece of Mars: Abstract modern art? No, these are north polar dunes almost completely covered in winter frost (mostly CO2 ice). It’s early spring in this image, and the dark sand underneath the ice is only just beginning to […]