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 […]
April 12, 2018

My 2018 Paper on Recent Climate Change in Meridiani Planum, Mars (Part 2)

In a previous post, I set the stage for my recently published paper in JGR Planets. A recap: we’ve got good evidence for a change in Mars’s climate. Widespread ripples in Meridiani Planum formed >200,000 years ago, last migrated westward […]
April 11, 2018

My 2018 paper on recent climate change in Meridiani Planum, Mars (Part 1)

Today a big thing happened: a paper I’ve spent a year or so working on has finally been published in the Journal of Geophysical Research: Planets (which we just call “JGR Planets”). Scientists write a lot of papers, so it’s […]
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 […]
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): (HiRISE ESP_045586_1585, NASA/JPL/Univ. of Arizona) The big crater is ~400 m (1/4 mile) across. Wind blows […]
March 5, 2018

“Baby” dunes on Mars are big

Baby dunes on Mars are pretty big compared to those on Earth. In this 885×512 m (0.55×0.32 mi) frame, there are four dunes of roughly the same size, all of which are about as small as dunes can get on […]
March 1, 2018

Dune trails

There’s so much going on in this 0.75×0.75 km (0.47×0.47 mi) image. You’re looking at a broad dune migrating toward the upper right. It’s early summer, but this is close enough to the north pole that some winter ice lingers […]