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Friday, May 14, 2010
Solar wind tans young asteroids
Unlike human skin which is damaged by prolonged exposure to sunlight over a lifetime, an asteroid's surface is aged in the first instances of its life.
Of course, the time scales of the exposure are much different: for an asteroid the damage is done over a period of one million years, but this is still a very short timeframe compared with the 4.6 billion year age of the Solar System itself.
New observations conducted using ESO's New Technology Telescope at La Silla and the Very Large Telescope at Paranal, astronomers have shed some light on this mystery. The astronomers looked at freshly exposed asteroid surfaces (caused by the collision of two asteroids) and noticed that they change colour in less than a million years.
The charged, fast moving particles in the solar wind damage the asteroid's surface at an amazing rate.The solar wind contains highly energetic particles that bombard the exposed surfaces of asteroids, eroding the molecules and crystals on the surface and rearranging them into different configurations with distinct colours and properties.
