#GoodbyePhilae: Time to say goodbye has come! – Point

We knew since the beginning of February. The chance to communicate again with the Philae robot had become almost – if not completely – zero. However, ESA and CNES had refused to make any official announcement, embarrassed at the idea of ​​publishing this early death certificate of the man who had become a real little character to the general public. But the time had come. Rosetta itself preparing to dive to end his life in a last kiss given to his tchouri comet on September 30

On Wednesday 27 July at 11 am, the the team’s mission has definitely cut the interface for communication between Philae and Rosetta, which he used relays in its communications with Earth. The opportunity for a last farewell to this small European robot that will be so thrilled us. As often in the history of the mission, it is the German space agency has unsheathed the first Tuesday with this tweet published in German and then in English: “Soon, communications with the lander will no longer be possible. Help us to say goodbye @ philae2014. ” After that, CNES and ESA have in turn issued their farewell message. Finally, it was the turn of Philae to salute the company for his own Twitter account.

It’s time for me to say goodbye. Tomorrow, the unit is @ESA_Rosetta for communication with me will be switched off forever …

– Philae Lander (@ Philae2014) July 26, 2016

Already on 11 January, the project manager for the Rosetta mission for CNES, Philippe Gaudon, explained that the calculations of experts, although approximate, predicted that from the end of January lander would no longer have sufficient sunshine to have the energy to manifest. The comet would already be too far away from our star and, in the area where the lander is supposed to be, the fall was about to install.

In the shadow of the rock beneath which he accidentally landed on the surface of tchouri, after bouncing twice Philae was therefore off gently. The control center of the European Space Agency (ESA) in Darmstadt, Germany, stayed a moment to listen, but the miracle did not happen. For those adventure of the little robot in charge of the first in situ exploration of a comet enthusiasts, the disappointment is great. However, the overall balance of the mission is very positive.

A historic feat

First, the European Space Agency has demonstrated its ability to send a probe, ten years ahead, to encounter a comet, to achieve orbit around the body whose gravity is very weak and finally there to drop a lander and to ensure that it falls where it wanted, even though it has rebounded thereafter.

“we must not forget that no one knew what would be the nature of the soil of a comet. Although the three devices were intended to dock Philae to the surface of the comet [his bow, his harpoons and tripod screw, Ed] did not work, but who could imagine that the robot was going to bounce that way and fly several hundred meters above the ground? “Said Michel Hut, researcher at Latmos (Laboratoire Atmospheres, backgrounds, space observation), team member of the instrument COSAC (Cometary Sampling and Composition) of Philae.

” We have no unlucky, but the engineers were able to validate expertise and have also learned a lot. Moreover, from a scientific point of view, all the instruments of Philae worked and each team was able to collect results, all unpublished! “Added planetary scientist exobiologist, which participates in the Rosetta mission from the beginning (read our paper on the results of Philae published in July 2015).

From an unknown world

ESA Philae received about 80% of the results that could be expected of him. Among the deficiencies, the team of the COSAC instrument finally never been able to analyze the sample of cometary soil. And because Philae never managed to collect. Due to the acrobatic robot position, one leg in the air, his drill, which was triggered just before the robot does assoupisse November 15, 2014, turned into space, clearly too far off the ground. “However, we realized that we had finally made about what we wanted since bouncing on the ground Philae raised a cloud of dust, some of which fell back into the instrument and were analyzed. As if we had a sample at a reduced rate! “Says Michel Hut.

” Of course, Philae, by operating only on its original battery, without ever managing to recover to operate on the energy delivered by the solar panels, only offered us that a one shot [by the English expression used to mean "a coup", Ed]. He has realized that the operations for which it was preprogrammed. Obviously, if he could work more, we would have, too, could work more: check, cross-check, repeat the experiments by modifying certain parameters, etc. It is this opportunity that rebounds Philae deprived us “, explains the scientist.

However, this” one shot “Philae will permanently changed our vision of what comets, these objects precious which contain primordial material of our solar system. “We found items that we knew almost everything and in which almost everything we thought proved false,” says Jean-Pierre Bibring, scientific manager of Philae. “A comet is not a dirty snowball that would have trapped some organic molecules. It is quite another thing. They are much more complex objects than we could imagine “, recognizes the astrophysicist.

A possible role in the emergence of life

” Philae showed that material that is on the surface, and that is probably the overall material of the comet, a carbon structure is very sparse but rich of great complexity, particularly in terms of organic molecules. This confirms very clearly the notion that these molecules could play a major role in the emergence of life, among other things, on Earth, “says Jean-Pierre Bibring. And although Philae definitively ceased to issue, researchers exploiting its data themselves are far from having said their last word. The information he has transmitted in just three short days of activity will probably continue long to enlighten us, both children of our solar system as the origin of life that appeared there.

in the meantime, the little robot, he seems to have trouble cutting the cord with Earth. “I am far from Earth and the Sun! I would like to keep memories of you with me. Please send me postcards! “Has he said via his Twitter account.

Philae Fans have until August 8 to send a picture of them saying goodbye to the robot or on different social networks by adding the hashtag #GoodbyePhilae or by email at GoodbyePhilae@dlr.de.