Note: I am posting my old blog entries from elsewhere on the internet. This entry was originally posted on 6/19/08.
As you may have heard, a few sols ago we got an anomaly onboard Phoenix – one of the spacecraft housekeeping activities generated over ten thousand times the amount of data expected, and the flash memory was overwritten. (Flash memory is a type of long-term memory that can keep information even when not powered on, like your hard drive or a USB stick. At the end of each sol before it goes into sleep mode, Phoenix takes whatever data hasn’t been sent back to Earth and transfers it to flash for downloading on a future sol.) Luckily, it sounds like we only lost low-priority science that can be retaken. We postponed a day of science to let the spacecraft team start troubleshooting, but we are now continuing science operations. However, we are not using the flash memory for the next few sols, and are assuming that any data not downlinked by the end of the sol is lost.
Lately, we’ve been doing a lot of atmospheric observations – temperature, humidity, wind speed, and the amount of dust or clouds in the atmosphere – at the same time that one of the orbiters, MRO, is flying overhead looking down. This “coordinated science” is intended to help figure out how what we see from orbit relates to what is going on down on the ground. We also have been keeping an eye on the areas where we’ve been digging to look for changes in the bright material. We haven’t been sure if the bright material is salt or ice, but now we know: it’s ice! Here you can see two images; the first one was taken shortly after digging and you can see little clods of bright material in the lower left corner. The second image was taken several sols later; the clods have vanished. This is due to a process called “sublimation” where a material goes from a solid directly to a gas, without becoming water in between. This is something that we know water ice does on the surface of Mars, but it is impossible for a salt to do this. Therefore, we have definitely found ice!
Yesterday we started digging a new trench. The robotic arm has found a hard layer about 5 cm down in this trench, so we may be about to uncover some more ice. The plan for today is to scoop up some dirt right next to the trench and deliver some to TEGA and the optical microscope, and maybe the wet chemistry portion of MECA as well. TEGA is continuing with the next bake of the sample it already has, at a higher temperature range. So although there’s some hiccups, we’re still doing a lot and have three downlink passes scheduled to get everything down.
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