EUROPE: The comet being observed by Europe’s Rosetta satellite is very gradually spinning down.
The icy dirt-ball takes 12.4 hours to complete one rotation, but mission controllers have noticed that this is extending by about a second a day.
And this rate of change is increasing as Comet 67P gets more active.
“The gas jets coming out of the comet – they are acting like thrusters and are slowing down the comet,” said flight director Andrea Accomazzo.
The European Space Agency official was speaking this week at the Royal Aeronautical Society in London.
He was describing how his team has learnt to fly Rosetta around the 10-billion-tonne, 4km-wide body with remarkable precision.
Navigators use a system of landmarks on the comet to understand how it is rotating and moving through space.
