Image of emissions of water vapor and other compounds from the comet 67P/Churyumov-Gerasimenko taken by one of the cameras of the Rosetta space probe's OSIRIS set (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/ INTA/UPM/DASP/IDA)

While the Rosetta space probe’s Philae lander prepares to land on the comet 67P/Churyumov-Gerasimenko on November 12, the analyzes at a distance go on. The comet is about 450 million kilometers (about 280 million miles) from the Sun and its activity is increasing due to the sublimation of the ice, which becomes steam. The ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instrument has already analyzed some emissions finding that the comet really stinks.

The comet C/2013 A1 Siding Spring observed by the WISE space telescope (Image NASA/JPL-Caltech)

Yesterday the comet C/2013 A1, also known as Siding Spring, passed very close to Mars. The distance from the planet was as low as about 140,000 km (about 87,000 miles), one third of the distance of the Moon from Earth, very close in astronomical terms. The event was followed by several telescopes but nearby ther was was the Earth’s “star fleet” consisting of NASA’s probes and rovers, ESA’s Mars Express probe and the Indian MOM – aka Mangalyaan – probe.

Map of the surface of the comet 67P/Churyumov-Gerasimenko showing in different colors the various morphological features (Image ESA/Rosetta/MPS for OSIRIS Team/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

A group of scientists who are studying the comet 67P/Churyumov-Gerasimenko has created a map based on the analysis of surface images taken by the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) instrument of the Rosetta space probe. The result is that the comet can be divided into different regions that have distinct physical appearancec. This map shows that it’s much more than a large rock mixed with ice.

The comet comet 67P/Churyumov-Gerasimenko with the 5 Philae candidate landing sites (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

The Rosetta space probe reached the comet 67P/Churyumov-Gerasimenko almost a month ago but remained at a distance from it of not less than 52 kilometers (about 32 miles). ESA’s scientists spent the last few weeks studying the comet, also to determine the route to follow for the probe and the Philae lander. Today, Rosetta is scheduled to start the series of maneuvers that in a few days will bring it at a distance of approximately 29 km (about 18 miles) from the comet to arrive later about 10 km (a bit more than 6 miles) from it.