July 17, 2020

Those crazy southern polar dunes

July 17, 2020 A couple months ago I wrote a blog post about defrosting dunes in Jeans crater, some wild southern polar dunes on Mars. Well it’s been that time of year on Mars, so I’m going to show some […]
June 15, 2020

The new crater

June 15, 2020 Utopia Planitia is an ancient plain in the northern lowlands of Mars, thought to be made of volcanic rocks that were buried, more than 3 billion years ago, by sediments carried by water coming down from the […]
June 8, 2020

Hills with tails

June 8, 2020 No long descriptions or explanations today, just a pretty picture of a lee dune (the dark rippled finger extending down the left side of this image): The rounded gray hills at the top are part of the […]
March 25, 2020

The landscape in Arabia Terra

March 25, 2020 It’s been an interesting few weeks. Like many folks, I’m trying to work from home while keeping my kids busy. I’m fortunate to have a job that allows me to work at home, so I can continue […]
October 18, 2018

The martian wind is a geologist

Right now, the Fourth Landing Site Workshop for the Mars 2020 rover mission is happening. It’s the last one, and in a few hours the scientists attending the workshop will vote on which of four sites they think the rover […]
September 24, 2018


Being a geomorphologist and reading a landscape is a little bit like being one of the forensic scientists on CSI (or choose your own favorite investigative show). A Mars geomorphologist usually has to do this entirely by remote sensing. So […]
March 12, 2018

Wind on Mars and the Huygens-Fresnel Principle

How about some basic physics? It’ll be easy, I promise. Just look at the pretty picture below (click on it to see it better): The big crater is ~400 m (1/4 mile) across. Wind blows sediment from the top to […]
January 30, 2018

Smash! Whoosh…

A Piece of Mars: The dark splash pattern in this 0.9×0.9 km (0.56×0.56 mi) scene (click on it for a better view) is the site of an impact crater that appeared between images sometime between August 2006 and March 2010 […]
December 26, 2017

Buried by ejecta

A Piece of Mars: To see this one well you’ll have to click on the image. At the lower right, a 240 m (787 ft) diameter crater formed when a bolide hit the surface, throwing out ejecta on the surrounding […]