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.
In late August, ESA identified 5 potential sites for the landing of the Philae lander, scheduled for November 11. Previously, the agency made a selection of 10 sites, identified by letters ranging from A to J, which was based on a careful analysis of high-resolution measurements made by Rosetta.
The comet is formed by two parts joined by a “neck”, which could be two nuclei that merged in the past. The sites A and C are on the biggest part of the comet while the sites B, I and J are on the smaller part. By September 15 they should announce of the choice of the primary site for the landing and a second as a backup.
The decision will be based on further evaluation of the 5 sites. It’s necessary that the Philae lander is able to maintain regular communications with the Rosetta space probe. Risk elements such as stones and other irregularities on the surface of the comet should be limited. Lighting should allow to perform scientific research but also to recharge Philae’s batteries.
The irregular shape of the comet 67P/Churyumov-Gerasimenko makes it more interesting than expected from the scientific point of view but made the mission more complex. To have the Rosetta spacecraft enter a stable and safe orbit, it’s necessary to know its gravitational characteristics. Its irregular shape made this task difficult but the ESA’s mission flight director Andrea Accomazzo stated he’s confident that the problem will be resolved in time.
In recent months, ESA released closer and closer images of the comet 67P/Churyumov-Gerasimenko. In the next few days more photos will arrive that will be even more detailed in a mission that is giving us a great show but is also extremely interesting from the scientific point of view.