barchan

February 17, 2020

Dome dunes

Feb. 17, 2020 I’ve been busy but I wanted to squeeze in a quick pretty picture of some Mars dunes. These: These dark hills of windblown sand are on the small side for Mars. The smallest is ~88 m (288 […]
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 […]
December 27, 2018

Wind at the Mars InSight landing site

InSight landed in Elysium Planitia on 26 November, 2018, about a month ago as of this writing. Pictures show that it’s a flat place, with small scattered rocks lying around. Unlike in Gale crater, where Curiosity is slowly working its […]
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 […]
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 […]
February 5, 2018

Mars’ “Type A” wind

The busy, busy wind has moved a lot of things to make this 0.6×0.85 km (0.37×0.53 mi) landscape. First it built a big dark dune, covering it and the surrounding surface with ripples. Then it dumped a bunch of bright […]
January 18, 2018

Varying wind directions

A Piece of Mars: This 0.5×0.4 km (0.31×0.25 mi) scene shows two dunes near the north pole. The shape of the dunes indicates two main winds: one blowing left to right (which makes slip faces on the right side, one […]
November 6, 2017

Black and tan

A Piece of Mars: Dunes in the top row in this 0.73×0.47 km (0.46×0.29 mi) scene are dark but those in the lower row are brighter. Why? They’re all probably made out of the same kind of sand, which is […]
September 17, 2017

Dust trapped on the lee side

A Piece of Mars: This 0.95×1 km (.59x.62 mi) scene shows the center of a small dune field. The dunes are shaped by three winds blowing from three different directions: from the west-southwest, east, and south. The north-facing slopes are […]