May | 2013 | Believe nothing

Pebbly Rocks Testify to Old Streambed On Mars

May 31, 2013 believenothing Leave a comment

May 30, 2013 — Detailed analysis and review have borne out researchers’ initial interpretation of pebble-containing slabs that NASA’s Mars rover Curiosity investigated last year: They are part of an ancient streambed.

NASA’s Curiosity rover found evidence for an ancient, flowing stream on Mars at a few sites, including the rock outcrop pictured here, which the science team has named “Hottah” after Hottah Lake in Canada’s Northwest Territories. It may look like a broken sidewalk, but this geological feature on Mars is actually exposed bedrock made up of smaller fragments cemented together, or what geologists call a sedimentary conglomerate. Scientists theorize that the bedrock was disrupted in the past, giving it the titled angle, most likely via impacts from meteorites. (Credit: NASA/JPL-Caltech/MSSS)

The rocks are the first ever found on Mars that contain streambed gravels. The sizes and shapes of the gravels embedded in these conglomerate rocks — from the size of sand particles to the size of golf balls — enabled researchers to calculate the depth and speed of the water that once flowed at this location.

“We completed more rigorous quantification of the outcrops to characterize the size distribution and roundness of the pebbles and sand that make up these conglomerates,” said Rebecca Williams of the Planetary Science Institute, Tucson, Ariz., lead author of a report about them in the journal Science this week. “We ended up with a calculation in the same range as our initial estimate last fall. At a minimum, the stream was flowing at a speed equivalent to a walking pace — a meter, or three feet, per second — and it was ankle-deep to hip-deep.”

Categories: Science/Astronomy Tags: astronomy, life on mars, mars, nasa, planet, rocks, science, solar system, space, water

Hubble Space Telescope Captures The Ring Nebula In Astonishing Detail

May 29, 2013 believenothing Leave a comment

By Clay Dillow Posted 05.24.2013

The Ring Nebula New images of the Ring Nebula captured by the Hubble Space Telescope are redefining the way astronomers understand its shape. NASA, ESA, C.R. Robert O’Dell (Vanderbilt University), G.J. Ferland (University of Kentucky), W.J. Henney and M. Peimbert (National Autonomous University of Mexico)

Astronomers love to point their telescopes at the Ring Nebula. Located 2,000 light years away in the constellation Lyra, this ring of glowing gas has a distinctive elliptical shape when seen from Earth. But new images captured by the Hubble Space Telescope suggest that the nebula actually looks a lot more like a football or a misshapen doughnut.