[X] My Assistant

[Guest_paulanderson_*]

Interesting new article re the fins and cracks in Meridiani, from UC Davis:

Soggy Sands of Mars?
http://www.news.ucdavis.edu/search/news_detail.lasso?id=7698

"Cracks and fins in the sand in an American desert look very similar to features seen on Mars and may indicate the recent presence of water at the surface, according to a new study by researcher Greg Chavdarian and Dawn Sumner, associate professor of geology at UC Davis. "Recent, as in ongoing now," Sumner said."

[djellison]

There's nothing in the rest of the article that explains why now and now 3 billion years ago...

"Chavdarian and Sumner think that the fins are formed when water seeps into cracks in the sand, carrying minerals with it. The water evaporates away, leaving behind those minerals, which are exposed as the wind blows sand away."

All fits with the curreny accepted model of Meridiani..

"Windblown material sticks to the exposed fin, making it larger and stronger. If the cracks and fins seen by the Opportunity rover on Mars are formed in the same way as the features at White Sands, it would provide evidence for water at the surface of Mars away from the polar ice caps"


We already have that in the rocks of Meridiani, just not today, but many years ago. Nothing really new at all in what he says. It's a bit tenuous however - all he has is "they look like" - and that's not a great basis on which to make the judgement he has.