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Archive for March 18, 2013

Curiosity Mars Rover Sees Trend In Water Presence


NASA’s Mars rover Curiosity has seen evidence of water-bearing minerals in rocks near where it had already found clay minerals inside a drilled rock.

Last week, the rover’s science team announced that analysis of powder from a drilled mudstone rock on Mars indicates past environmental conditions that were favorable for microbial life. Additional findings presented today (March 18) at a news briefing at the Lunar and Planetary Science Conference in The Woodlands, Texas, suggest those conditions extended beyond the site of the drilling.

Using infrared-imaging capability of a camera on the rover and an instrument that shoots neutrons into the ground to probe for hydrogen, researchers have found more hydration of minerals near the clay-bearing rock than at locations Curiosity visited earlier.

The rover’s Mast Camera (Mastcam) can also serve as a mineral-detecting and hydration-detecting tool, reported Jim Bell of Arizona State University, Tempe. “Some iron-bearing rocks and minerals can be detected and mapped using the Mastcam’s near-infrared filters.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-099

Famous Supernova Reveals Clues About Crucial Cosmic Distance Markers


Credit: X-ray: NASA/CXC/NCSU/M.Burkey et al; Infrared: NASA/JPL-Caltech

Credit: X-ray: NASA/CXC/NCSU/M.Burkey et al; Infrared: NASA/JPL-Caltech

A new study using data from NASA’s Chandra X-ray Observatory points to the origin of a famous supernova. This supernova, discovered in 1604 by Johannes Kepler, belongs to an important class of objects that are used to measure the rate of expansion of the Universe.

Astronomers have used a very long Chandra observation of the remnant of Kepler’s supernova to deduce that the supernova was triggered by an interaction between a white dwarf and a red giant star. This is significant because another study has already shown that a so-called Type Ia supernova caused the Kepler supernova remnant.

The thermonuclear explosion of a white dwarf star produces such supernovas. Because they explode with nearly uniform brightness, astronomers have used them as cosmic distance markers to track the accelerated expansion of the Universe.

However, there is an ongoing controversy about Type Ia supernovas. Are they caused by a white dwarf pulling so much material from a companion star that it becomes unstable and explodes? Or do they result from the merger of two white dwarfs?

“While we can’t speak to all Type Ia supernovas, our evidence points to Kepler being caused by a white dwarf pulling material from a companion star, and not the merger of two white dwarfs,” said the first author of the new Chandra study, Mary Burkey of North Carolina State University (NCSU). “To continue improving distance measurements with these supernovas, it is crucial to understand how they are triggered.”

Full Story: http://www.chandra.si.edu/press/13_releases/press_031813.html
Images: http://www.chandra.si.edu/photo/2013/kepler/