A couple of Mars items today:
NASA Mars Orbiters See Clues to Possible Water Flows
This image combines a photograph of seasonal dark flows on a Martian slope
with a grid of colors based on data collected by a mineral-mapping spectrometer
observing the same area. Image credit: NASA/JPL-Caltech/UA/JHU-APL
› Full image and caption
NASA spacecraft orbiting Mars have returned clues for understanding seasonal features that are the strongest indication of possible liquid water that may exist today on the Red Planet.
The features are dark, finger-like markings that advance down some Martian slopes when temperatures rise. The new clues include corresponding seasonal changes in iron minerals on the same slopes and a survey of ground temperatures and other traits at active sites. These support a suggestion that brines with an iron-mineral antifreeze, such as ferric sulfate, may flow seasonally, though there are still other possible explanations.
Researchers call these dark flows “recurring slope lineae.” As a result, RSL has become one of the hottest acronyms at meetings of Mars scientists.
“We still don’t have a smoking gun for existence of water in RSL, 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.
Ojha and Georgia Tech assistant professor James Wray more recently looked at 13 confirmed RSL sites using images from the same orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument. They searched for minerals that RSL might leave in their wake as a way of understanding the nature of these features: water-related or not?
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And Bill Dunford writes about some newly named hills on earth and includes several impressive images: New Hills, Old Secrets – The Planetary Society
There is a new set of hills on Mars. Well, the hills themselves aren’t new, but they have a new name. In the past couple of months, the International Astronomical Union has officially designated names for dozens of craters, cliffs, seas, and mountains on four different worlds. They include places like Nakuru Lacuna on Saturn’s moon Titan, Neptunalia Dorsa on the asteroid Vesta, and Mercury’s Lennon Crater, named for John.
Hidden Gullies: Overhanging cliffs near Simois Colles on Mars partially conceal
a set of gullies that appear to originate at specific rock layers. Imaged by the
HiRISE camera on board the Mars Reconnaissance Orbiter. The area shown
is approximately one kilometer wide. Credits: NASA / JPL / UA