active

November 29, 2013

Two-toned washboard on a hillside

A Piece of Mars: Two-toned ripples have formed on a steep slope, created by winds rushing downhill (from top to bottom in this frame). The larger ones are big ripples, with peaks more than 30 meters apart. What makes them […]
November 18, 2013

It’s a comet! No, wait…

A piece of Mars: Is it a comet? With Comet ISON in the news these days it’s hard to tell. No, this is a brand-new meteorite impact on the surface of Mars. The impactor hit the ground, blasted through a […]
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 […]
June 7, 2013

Blue ribbon

A piece of Mars: In ancient, wind-carved hills, a bluish ribbon of actively moving sand still winds its way. It is a remnant of a long-lived period of wind scour that shaped this landscape. (And it’s been stretched to look […]
April 16, 2013

Modern art or windy Mars?

A piece of Mars: Is it modern art? Well maybe it looks like it from a distance. Up close, this is reality on Mars. These are dark dunes in the southern hemisphere, awaking from a long hibernation beneath bright winter […]
March 27, 2013

Giant crayons on Mars

A piece of Mars: There are vast plains on Mars that display criss-crossing streaks like this. These are ~5 m (~16 feet) across, give or take. Did an alien drive a dune buggy all over, leaving behind tracks? Nope. These […]
March 19, 2013

Nili Patera

A piece of Mars: Nili Patera on Mars is an ancient volcano. Some of the old volcanic material has been blown into rather striking sand dunes. It is the first place where dunes were conclusively identified as actively moving. Here’s […]