March 29, 2021

Once covered, now revealed

March 29, 2021 Mars is such a fun place. We’re finding out that it’s got oodles of geologic history. It’s got layers deposited by wind and water and lava, altered in place (sometimes many times), then eroded again by wind […]
February 1, 2021

Both wind-carved *and* ancient

1 February, 2021 Are we tired of the pandemic yet? My kids haven’t gone to an actual school since last March. Fortunately we’re all healthy. I’m able to do most of my work, but it’s not easy. So let’s go […]
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 […]
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 […]
March 26, 2018

Wind-exposed layers

On Earth, layers comprising the geological record of an area are most often exposed by fluvial erosion, as a river cuts through rock (a typical example is the Grand Canyon). On Mars, fluvial channels are not so common (especially in […]
March 19, 2018

Dune trails deep in Hebes Chasma, Mars

A few weeks ago I wrote about dunes leaving behind trails near the north pole of Mars. They do this in a few other places as well, but it’s not very common. Below is a rare example, this time on […]
November 15, 2017


A Piece of Mars: There’s a fabric of erosion in this 1×1 km (0.62×0.62 mi) scene, with the main wind blowing from lower right to upper left (and if you look carefully you’ll see there’s a second, subtler fabric a […]
October 23, 2017

Just do it

A Piece of Mars: It’s all about wind scour here in this 0.75×0.75 km (0.47×0.47 mi) view. The big “swoop” is an erosional channel dug into the surface by winds (blowing from the lower left) trying to erode the hills […]
August 28, 2017

Endless wind

A Piece of Mars: This 2.88×1.13 km (1.79×0.70 mi) scene shows quintessential Mars, with a 670 m diameter impact crater heavily modified by wind erosion. Both the crater floor and the surrounding terrain are covered by what is likely loosely-cemented […]