NASA to Announce Mars Mystery Solved

"**Nature Geoscience has Embargoed Details until 8 a.m. PDT/11 a.m. EDT Sept. 28)**

NASA will detail a major science finding from the agency's ongoing exploration of Mars during a news briefing at 8:30 a.m. PDT (11:30 a.m. EDT) on Monday, Sept. 28 at the James Webb Auditorium at NASA Headquarters in Washington. The event will be broadcast live on NASA Television and the agency's website."

Keith's 24 Sep note: As is standard practice NASA JPL and researchers have already provided advance information on this news to hand-picked news media - but not to others. But let's try and figure out what the big 'ol mystery is. Lujendra Ojha is one of the presenters at the press event and he's totally into recurring slope lineae on Mars using MRO. Alfred McEwen is a frequent co-author. And they have been trying to figure out how these features form on Mars. One would assume that they have figured that out.

NASA Mars Orbiters See Clues to Possible Water Flows (2014)

"We still don't have a smoking gun for existence of water in RSL [recurring slope lineae], although we're not sure how this process would take place without water," said Lujendra Ojha, a graduate student at the Georgia Institute of Technology, Atlanta, and lead author of two new reports about these flows. He originally discovered them while an undergraduate at the University of Arizona, Tucson, three years ago, in images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter."

Recurring slope lineae in equatorial regions of Mars, Nature (2013)

"The presence of liquid water is a requirement of habitability on a planet. Possible indicators of liquid surface water on Mars include intermittent flow-like features observed on sloping terrains. These recurring slope lineae are narrow, dark markings on steep slopes that appear and incrementally lengthen during warm seasons on low-albedo surfaces."

Keith's 24 Sep update: A NASAWatch reader artfully tipped us off to this session of the European Planetary Science Congress 2015 in France on Monday, 28 September - and one paper authored by several of the participants (McEwen and Ojha) in the NASA press conference:

17:00-17:15 EPSC2015-786 Recurring Slope Lineae on Mars: Atmospheric Origin?, AS McEwen, M Chojnacki, C Dundas, L Ojha, M Masse, E Schaefer, and C Leung

"Recurring Slope Lineae (RSL) are seasonal flows or seeps on warm Martian slopes. Observed gradual or incremental growth, fading, and yearly recurrence can be explained by seasonal seeps of water, which is probably salty. The origin of the water is not understood, but several observations indicate a key role for atmospheric processes. If sufficient deliquescent salts are present at these locations, the water could be entirely of atmospheric origin."