Every so often I come across a photo that’s just so otherworldly, I have to share it with all my friends. You’re looking at a pit in the “Swiss cheese” terrain near the south polar cap of Mars released this week by NASA. They call it the Deranged Happy Face. The weird terrain consists of frozen carbon dioxide (dry ice) that sublimates or turns directly from a solid to a gas during the Martian summer and then reforms as the temperature drops in the fall.
The 24-hour sun shining at a low angle during the summer heats the walls more than the floors of the pits, causing them to vaporize and expand and change the pits’ outlines. Take a look at these side by side comparison photos of the Deranged Happy Face taken in June 2007 and December 2010. You’ll see lots of changes in its features caused by cycles of vaporization and recondensation of dry ice.
To this date, no cheddar or Brie have been discovered on the Red Planet, though I remain hopeful that will change as instrumentation improves.
NanoSail-D, NASA’s grand first experiment using solar sail technology, is orbiting 404 miles above the Earth and proving very tricky to spot. Only a few dedicated satellite watchers have succeeded in tracking it. From what I’m hearing, it’s been caught flashing as bright as 2nd magnitude or similar to stars in the Big Dipper. At other times, the sail’s been 7th or 8th magnitude, requiring binoculars to see.
Although NASA scientists hope to measure the pressure of sunlight on the sail, its primary mission is to determine the degree of drag on the sail caused by the rarefied upper atmosphere.
“Our mission is to circle Earth and investigate the possibility of using solar sails as a tool to de-orbit old satellites and space junk,” explains Dale Alhorn, NanoSail-D principal investigator. “As the sail orbits our planet, it skims the top of our atmosphere and experiences aerodynamic drag. Eventually, this brings it down.”
The hope is that future satellites can be equipped with sails that would pop out like umbrellas. Once deployed, the satellite would return to Earth via aerodynamic drag, burning up harmlessly in the atmosphere. Given all the space junk in orbit, sails might be a good start to getting rid of stuff we no longer use up there.Â Read more about the topic HERE.
For the Duluth region, NanoSail-D will fly by for the last time in a couple of weeks tonight starting at 5:30 p.m. Traveling from the west to northeast very low in the sky, it will pass less than a degree below the bright star Vega at 5:32:30 p.m. moving from the left (west) to east (right). For times for your town, login to Heavens Above or click on Spaceweather’s satellite flyby site and enter your zip code.
If you’d like to try your hand at photography and maybe even win a few hundred bucks, NASA and Spaceweather. com have launched a photo contest to see who can shoot the best pictures of NanoSail-D. Anyone can participate. They’re looking for everything from pictures taken by point-and-shoot cameras to carefully guided images made through large telescopes. The photos will be judged on beauty and technical merit; prizes range from $500 for first place to $100 for third. Click HERE to learn more and enter.