25th October 2014
Dunes visible on comet 67P
In August, the European Space Agency (ESA) achieved a major success when its Rosetta probe rendezvoused with comet 67P. The spacecraft has been returning spectacular images of this strange little world, located midway between the orbits of Mars and Jupiter. Among its latest photographs is the image below showing what appear to be dunes like those found on the deserts and beaches of Earth. Seen from a distance of about 8.8 km (5.5 miles), the scale here is 92 cm/pixel, meaning the dunes are roughly the width of a jumbo jet (as shown in this helpful illustration from Reddit).
The comet is already becoming more active as it approaches the Sun, with jets of dust shooting outward in slowly increasing quantities. Data from the mass spectrometers on Rosetta show that its coma (or atmosphere) contains a surprisingly rich variety of chemicals. Although low density, this would smell terrible, were humans able to experience it.
A surface lander is due to touch down on 12th November. Philae will take seven hours to land and is equipped with a 1024 x 1024 pixel CCD. If all goes according to plan, this will take images both during its final descent phase and on the surface, when the camera will be 30 cm above the ground. Its field of view will be roughly 30 x 30 cm, giving a resolution of 0.3 mm/pixel. You can follow the latest developments on the ESA blog (where many more images can be found) and via Twitter @ ESA_Rosetta.
*UPDATE*: See also this short sci-fi movie to promote the mission.