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Archive for June 25, 2014

Curiosity Travels Through Ancient Glaciers On Mars


Credit: CTX-MRO-NASA

Credit: CTX-MRO-NASA

NASA’s Mars Curiosity Rover has completed a Martian year –687 Earth days– this week. The vehicle travels through an arid and reddish landscape that was home to glaciers in the past. Ancient Mars held large quantities of water, yet its global hydro-geological cycles were very cold, so much so that they induced the presence of a giant ocean, partially ice-covered and rimmed by glaciers on the lower plains of the northern hemisphere.

Now, an international team of researchers has confirmed this global picture locally, on the Martian site where Curiosity is roving: Gale crater. “This crater was covered by glaciers approximately 3,500 million years ago, which were particularly extensive on its central mound, Aeolis Mons” points to SINC the lead investigator of the study Alberto Fairén, from the Centro de Astrobiología (INTA-CSIC) in Spain and Cornell University in the USA.

“However, at that time there were also rivers and lakes with very cold liquid water in the lower-lying areas within the crater,” adds the researcher, who highlights the fact that ancient Mars was capable of “maintaining large quantities of liquid water (an essential element for life) at the same time that giant ice sheets covered extensive regions of its surface”.

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Trio Of Supermassive Black Holes Shake Space-Time


Astronomers have discovered three closely orbiting supermassive black holes in a galaxy more than 4 billion light years away. This is the tightest trio of black holes known to date and is remarkable since most galaxies have just one at their centre (usually with a mass between 1 million to 10 billion times that of the Sun). The discovery suggests that these closely packed supermassive black holes are far more common than previously thought. The team, led by South African Dr Roger Deane from the University of Cape Town, used a technique called Very Long Baseline Interferometry (VLBI) to discover the inner two black holes of the triple system. This technique combines the signals from large radio antennas separated by up to 10 000 kilometres to see detail 50 times finer than that possible with the Hubble Space Telescope. The observations were done with the European VLBI Network (EVN) and the data were correlated at the Joint Institute for VLBI in Europe (JIVE) in Dwingeloo, the Netherlands.

“What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein’s Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth”, says Deane. “Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe. It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometre Array (SKA).”

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