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, […]
August 13, 2018

Where dunes once trod

Mars has been dusty, and that’s affecting the quality of HiRISE images (just look at the recent images in the catalog and you’ll see they’re not that great). That’s made it hard for me to choose a good one for […]
August 2, 2018

Oh, Mars!

The HiRISE camera has a website called HiWish that lets anybody (yes, even you!) make image requests. That’s right, you can choose any spot on Mars that HiRISE can see, pick any season (or let them pick for you if […]
July 16, 2018

Spring is a messy time

In many areas on Earth that get winter snow, spring thaw is a messy time. Frozen ground turns to mud, and there may be runoff everywhere from melting snow and spring rain. Or if you live in a place that […]
July 8, 2018

Field of barchans

It’s July, and I’ve had a busy summer so far. This is my first post in a few weeks – I’ve been out at various meetings, and last week I spent with my family on vacation. The one week of […]
May 30, 2018

The Mars Global Digital Dune Database

There are a lot of dune fields on Mars. Over the last ten years I’ve been part of a group that’s mapped out the big dark dunes on the planet to see where they form, and to understand the sedimentary […]
May 9, 2018

Entourage

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 […]