Publication Date:
2011-08-06
Description:
Water probably flowed across ancient Mars, but whether it ever exists as a liquid on the surface today remains debatable. Recurring slope lineae (RSL) are narrow (0.5 to 5 meters), relatively dark markings on steep (25 degrees to 40 degrees ) slopes; repeat images from the Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment show them to appear and incrementally grow during warm seasons and fade in cold seasons. They extend downslope from bedrock outcrops, often associated with small channels, and hundreds of them form in some rare locations. RSL appear and lengthen in the late southern spring and summer from 48 degrees S to 32 degrees S latitudes favoring equator-facing slopes, which are times and places with peak surface temperatures from ~250 to 300 kelvin. Liquid brines near the surface might explain this activity, but the exact mechanism and source of water are not understood.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McEwen, Alfred S -- Ojha, Lujendra -- Dundas, Colin M -- Mattson, Sarah S -- Byrne, Shane -- Wray, James J -- Cull, Selby C -- Murchie, Scott L -- Thomas, Nicolas -- Gulick, Virginia C -- New York, N.Y. -- Science. 2011 Aug 5;333(6043):740-3. doi: 10.1126/science.1204816.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA. mcewen@lpl.arizona.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21817049" target="_blank"〉PubMed〈/a〉
Keywords:
Extraterrestrial Environment
;
*Mars
;
Salts
;
Seasons
;
Spacecraft
;
Temperature
;
*Water
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
