ROSETTA ORBITS COMET

The European Space Agency spacecraft Rosetta arrived at Comet 67P/Churyumov-Gerasimenko on 6 August on schedule more than 10 years after launch from Earth.
http://www.bbc.co.uk/news/science-environment-28659783

Rosetta is now 550 million kilometres from earth. Signals take 22 minutes between Earth and Rosetta.

Rosetta is now travelling alongside the comet, some 100 kilometres distant, and will continue to follow the comet for the next 15 months. In November a harpoon is planned to anchor a lander Philae to the surface of Comet 67P.

Rosetta carries a thermal imaging spectrometer VIRTIS which has recorded temperatures on the comet around -70 degrees C, about 20 degrees warmer than expected.

Comment: This is a remarkable mission carrying out an important and unique detailed scientific study of a comet. If Philae lands successfully it will be a wonderful technical achievement with potentially significant results for our understanding of comets. Interestingly, because of the small size and low gravity of 67P, Rosetta is not actually in orbit, but is maintained in a triangular path around the comet by firing thrusters.