space boffins might like this story..
http://www.abc.net.au/science/articles/2014/08/04/4057060.htm?WT.mc_id=Innovation_Innovation-Science|RosettaHasAlmostLanded_FBP|abc
After a 10-year chase through space, the Rosetta spacecraft has caught up with the comet that will reveal secrets of our solar system. The next few months will be critical for the historic mission.
Comets are older than the solar system itself — frozen leftovers of the same primordial dust and gas from which the Sun and planets formed. To study the composition of a comet is to glimpse back more than 4.6 billion years in time and chemistry.
Of the billions of comets in our system, only a few have been seen up close, and none has undergone the kind of rigorous examination that Comet 67P/Churyumov-Gerasimenko will be subjected to over upcoming months.
For the last 10 years, the Rosetta spacecraft has been on a mission to catch up with the comet as it hurtles towards the Sun from deep space.
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