dunes

September 2, 2020

Dune on a hill

Sept. 2, 2020 Dunes don’t usually form on hills. They’re made of sand, which is moved by wind (and water and ice) and tends to linger where it gets stuck. You probably know this intimately if you’ve spent time at […]
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 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 […]
May 26, 2020

Defrosting dunes in Jeans crater

May 26, 2020 There are sand dunes near both the north and south poles of Mars. The ones I’m showing today are on the floor of Jeans crater, which is down at 69.5°S (for reference, on Earth, some bits of […]
November 11, 2019

When dunes vary in color

Nov. 11, 2019 It’s Veterans Day in the US today. For some it’s another day of work. For others it’s a day to spend with the family. For most, we honor those who have served in our armed forces. I’m […]
October 1, 2019

Wind and sun on the dunes

Oct. 1, 2019 It’s spring in the northern hemisphere on Mars. Actually, as of today, it’s pretty close to northern summer solstice, but the recent crop of released HiRISE images mostly come from the spring season. Northern polar dunes on […]
August 21, 2019

Dunes or bacteria?

Aug. 21, 2019 Trolling through the HiRISE image catalog, I came across some dunes that look a bit like bacteria. (Well okay, they look like some sort of microbe to my eye, which is highly untrained in looking at microbes, […]
August 5, 2019

Bask in Mars’ beauty, because you can

August 5, 2019 It’s been a while since I posted anything. Not because I didn’t want to, but because I’m involved in so many projects that many things I love are being shoved aside for whatever has to be dealt […]
March 4, 2019

Old dunes and new dunes

On Earth, really old windblown dunes don’t usually survive long enough to become part of the geologic rock record. Dunes are made of unconsolidated sand, which is easily eroded by just about anything, so it takes special circumstances to keep […]