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 […]
September 13, 2018

Ever shifting

Dunes are just so amazingly beautiful. I’ll never get over how nature can sculpt such regular patterns into endlessly overlapping structures. Here’s a small bit of a dune field trapped up high between mountains in the middle of Coprates Chasma. […]
August 28, 2018

The end of winter

Richardson crater is located at 72ºS, about 1000 km (~621 miles) from the south pole of Mars. It’s a moderately large crater, about 90 km (56) miles across, and it’s mostly filled by one of the biggest dune fields in […]
August 21, 2018

Different sands

There’s a lot we don’t understand about the sediment on Mars. Water, wind, ice, changing temperatures, and volcanic eruptions can all break rocks into grains small enough for the wind to transport. The smallest grains are lofted by the wind, […]
May 9, 2018


Here’s a grand dune, making its stately way northward under winds blowing mainly from the south-southeast (bottom to top), with a secondary wind blowing from the southwest (lower left to upper right). There are two rippled and sharp-crested slip faces […]
April 16, 2018

Flow. Lots of flow.

Over the years, many things have flowed across the surface of Mars: lava, ice, water, and wind. Two things have flowed in this image (the view is 0.75×0.6 km or 0.47×0.37 mi): Image credit: HiRISE ESP_026541_1840, NASA/JPL/Univ. of Arizona If […]
April 13, 2018

My 2018 paper on recent climate change in Meridiani Planum, Mars (Part 3)

This is the 3rd (and final) entry in a blog series describing a paper I recently published with colleagues in JGR Planets. Here are links to the previous two entries: Part 1, Part 2. Wow, I didn’t think this would […]
January 2, 2018

Fuzzy dunes

A Piece of Mars: The dunes (or maybe they’re ripples) in this valley appear to be fuzzy (the view is 625×775 m, 0.39×0.48 mi). They’re not really fuzzy, but it’s not actually clear what’s going on. They seem to have […]
December 4, 2017

Ripples of rock

A Piece of Mars: To the upper right of this 0.85×0.6 km (0.53×0.37 mi) scene is a flat-lying plain strewn with large ripples. To the lower left is a rugged hill with gray rock laced with white veins (this might […]