Thursday, August 14, 2014

A higher than expected flow of micrometeorites at least 50 times

A video presentation of Gaia and its scientific mission. © euronews, YouTube

Before you really begin his harvest of observations that should last until 2019, astronomers and engineers were careful, of course, to check that all was well. However, they found minor disturbances. Despite his visor 10m diameter responsible for maintaining a steady temperature to avoid mechanical deformation may reduce the accuracy of measurements, a light parasite stronger than expected entered the instruments.

The telescope itself expands and contracts from tens of nanometers to more than expected. Finally, small amounts of water that were trapped in the machine before its launch are sublimated in the vacuum of space before condensing on the mirror , again in larger quantities we imagined. The mission itself is not compromised, but it should change the string of measures intended to make the necessary corrections and data taking was therefore postponed, therefore, a few months.

A higher than expected flow of micrometeorites at least 50 times
http://androidstars.newsvine.com/_news/2014/08/05/25184554-fly-the-mission-stardust
http://androidgeek.ucoz.com/blog/there_would_be_oxygen_in_the_earth_39_s_core/2014-08-06-19
http://carmiell.blogspot.com/2014/08/july-news-that-should-not-be-missed.html

A surprise was still to go. To achieve its mission, Gaia needs to be pointed very precisely in one direction, which means to know its rotation on itself. Micrometeorite impacts could bias the telescope pointing. Now, from experience with other instruments already joined the L2 Lagrange point , as Planck and Herschel, it was expected to flow micrometeorites impacting Gaia from 1 to 10 per day. Instead, the sensitivity of the instruments showed he was on the order of 500 per day!

According to astronomer Floor van Leeuwen , of the Institute of Astronomy in Cambridge (UK) and member of the responsible cooperation of Gaia, although the origin of these micrometeorites is not yet well established, they could come from a dust ring surrounding the Earth , more or less associated with the Lagrange points. His colleague Nigel Hambly, University of Edinburgh, even think he could be a remnant of the formation of the Earth and the Moon .  Whatever the cause, Gaia is now ready to begin his campaign observations.

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