Bad Astronomy 3 Mar 2014, 12:45 UTC What’s the last thing a Romulan commander sees on their tactical screen before a volley of phasers turns them into space vapor? I’m guessing this: That’s not a bunch of Federation symbols flying across some alien world. Well, it is an alien world, but it’s not in the distant reaches of the Alpha Quadrant: That’s Mars, and those are actually sand dunes, seen by the HiRISE camera on board the Mars Reconnaissance Orbiter. Technically, they’re called barchan dunes. They can form when the wind blows predominantly from one direction. If there’s an obstacle, like a big rock or small hill, the wind will blow around the obstacle, the same way water flows around a rock. Sand will pile up on the leading edge, and also be swept around to the backside. Eddies in the wind create circular currents on the downwind side, building up walls of sand on the sides and creating that horseshoe crab-like appearance. Eventually, you get a long, shallow slope leading to a crest, a sharp edge, then a steeper slope downwind. The wind supports the sand from rolling back down the upwind side, but downwind the sand is free to roll down, creating a steeper slope. ...
NASA Astrobiology 3 Mar 2014, 10:37 UTC An artist's impression of a planet-forming disk. Credit: NASA/JPL-Caltech/T. Pyle (SSC) A team of astrobiologists supported by the NAI has shed new light on the mechanisms that fractionate carbon isotopes in planetary bodies. Their work shows that significant fractionation of carbon isotopes in nature may be the result of diffusion in iron-nickel metal, which is found inside planets and meteorites. Carbon is all around us. Life on Earth is carbon based, but the element is also abundant in the composition of planets and meteorites. By studying how different isotopes of carbon are formed, astrobiologists are able to gain clues about both the modern Earth and the evolution of the early solar system. The paper, “Diffusive fractionation of carbon isotopes in γ-Fe: Experiment, models and implications for early solar system processes,” was published in Geochimica et Cosmochimica Acta in February, 2014. Source: [Geochimica et Cosmochimica Acta]
Starts With a Bang! 28 Feb 2014, 23:35 UTC “You can’t get there by bus, only by hard work and risk and by not quite knowing what you’re doing.
collectSPACE.com: Space History News 28 Feb 2014, 22:15 UTC With the flick of a digital switch, the NASA Dryden Flight Research Center in California has been renamed in honor of the late Neil Armstrong, who in July 1969 was the first to walk on the moon. The new name is the Neil A. Armstrong Flight Research Center.
SPACE.com 28 Feb 2014, 20:00 UTC The now-famous supernova that erupted in neighboring galaxy M82 last month is a unique opportunity to study an exploding star up-close. However, SN 2014J isn’t any old supernova, it turns out that it’s a little bit weird.
The Planetary Society Blog 28 Feb 2014, 18:25 UTC Today's post continues where we started last week with an update from the Mars Express Flight Control Team at ESOC on their preparations for the 19 October Comet Siding Springs flyby. Today: defining the challenge!
The Guardian 28 Feb 2014, 17:28 UTC Rare sightings of aurora borealis as far south as Essex and Jersey, with grand displays in Scotland and north-east England• Did you spot the northern lights? Send us your images• The northern lights illuminate the UK – in picturesFor one night only the northern lights came south, seen in spectacular displays of green, pink and crimson as far south as Essex and Jersey.The light show by the aurora borealis on Thursday night – the result of an unusually clear, cold night combined with a strong solar storm – was also seen in many parts of Scotland and Northern Ireland, and across the north and east coasts of England.As word and stunning images spread on Twitter and other social media, amateur photographers across the country rushed out into the darkness. There were displays visible from Glasgow, Orkney, Preston in Lancashire, and Whitley Bay in north Tyneside. Much rarer were the sightings in Norfolk, Gloucestershire, south Wales, Essex and JerseyMark Thompson, presenter of the BBC's Stargazing Live, said it was a far more impressive display than he had been expecting, the best he had seen in 20 years.AuroraWatch UK, run by the space physicists at Lancaster University, which posts alerts when the ...