Wednesday, May 5, 2010

The Frozen Dunes of Mars Revisited

Posted By on Wed, May 5, 2010 at 10:46 PM

ESP_017043_2640.jpg
  • NASA/JPL/University of Arizona

The UA Lunar and Planetary Lab has released a particularly beautiful new batch of HiRISE photos of the Martian surface this week. See them here.

Don't forget: The LPL is having a picnic on Mount Lemmon on Saturday, May 22. Details on how to make your reservations before the May 14 deadline here.

HiRISE team member Ken Herkenhoff tells us about the photograph:

Like Earth, Mars has seasonal polar caps that grow in the winter and retreat in the spring, but on Mars the seasonal caps are composed primarily of carbon dioxide (dry ice). Carbon dioxide is the major component of the Martian atmosphere, and a significant fraction

of the mass of the atmosphere is cycled through the seasonal caps every year.

This image shows sand dunes that are mostly covered by seasonal frost/ice in the northern spring. When the springtime sun shines on the ice, some of it penetrates to the base of the ice and warms the dark sand dune surface below. The warm sand evaporates the carbon dioxide ice from below, building gas pressure that apparently breaks the ice and carries sand to the surface as the pressure is released. The sand then cascades down the surface of the ice, forming the streaks seen in this image.

Comments

Subscribe to this thread:

Add a comment

Previously in the Range

More by Jim Nintzel

  • Editor’s note

    On the Road Again
    • Sep 20, 2018
  • The Skinny

    Why Lea Márquez Peterson won’t say whether she’s OK with locking up undocumented kids
    • Sep 20, 2018
  • And They’re Off!

    Governor’s race is the highlight of the statewide campaigns now underway
    • Sep 13, 2018
  • More »
Today | Sat | Sun | Mon | Tue | Wed | Thu
Meditation and Buddhist study

Meditation and Buddhist study @ Sky Island Zen

Tuesdays, Saturdays

All of today's events | Staff Picks

Staff Pick

@ Mission Garden Saturdays, 8 a.m.-12 p.m. Continues through Nov. 24 Corner of Grande Avenue and Mission Lane.

» More Picks

Submit an Event Listing

Popular Content

  1. 22 Great Things to Do in Tucson This Weekend: Sept. 21-Sept. 23 (The Range: The Tucson Weekly's Daily Dispatch)
  2. Claytoon of the Day: The More Things Change (The Range: The Tucson Weekly's Daily Dispatch)
  3. Claytoon of the Day: Bert, Ernie, and Squirmy (The Range: The Tucson Weekly's Daily Dispatch)
  4. Help Cats by Eating BBQ! (The Range: The Tucson Weekly's Daily Dispatch)
  5. Laughing Stock: Laughing All Over (The Range: The Tucson Weekly's Daily Dispatch)

© 2018 Tucson Weekly | 7225 Mona Lisa Rd. Ste. 125, Tucson AZ 85741 | (520) 797-4384 | Powered by Foundation