Comet Siding Spring came extraordinarily close to Mars on 19 October 2014. The celestial body - a mere 500 metres in diameter - passed the Red Planet at a distance of just 137,000 kilometres, where it was observed by several spacecraft in orbit around Mars.
Among the most interesting landforms on Mars are features referred to as 'chaotic terrain'. Dozens or even hundreds of isolated mountains up to 2000 metres high are scattered in these extensive regions. Seen from orbit, they form a bizarre, chaotic pattern.
Aircraft engine noise is a socially pressing issue with a wide range of causes. Until now, turbulent fluctuations in the exhaust gas stream have not been fully understood as one of the major sources of noise. Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have now managed to make these turbulent flow structures in the engine exhaust gases visible using imaging laser measurement technology, and they have measured the overall flow behind the engine with unprecedented quality. Future generations of engines will be able to benefit from this new knowledge.
On 20 April 2014, the High Resolution Stereo Camera (HRSC) on the ESA Mars Express spacecraft, which is operated by DLR, imaged the northern part of the enormous Argyre Planitia impact basin in the southern hemisphere of Mars. At that time, it was deep winter in the area, as can easily be seen from the ground frost covering the interior of Hooke Crater and large sections of the landscape in the image.
When the Philae lander touches down on 11 November 2014, Comet 67P/Churyumov-Gerasimenko will have a landing site waiting for it with a varied but not too rugged landscape offering good solar illumination and hardly any steep slopes. In a two-day selection process, the lander team under the leadership of DLR selected landing site 'J' from among five possible candidates.
When looking at Mars through a telescope, once does not usually recognise many landscape features – especially since observations are often affected by dust storms that rage in the Martian atmosphere. The Hellas Planitia impact basin is, however, visible as a large, light, almost circular area in the southern hemisphere. Images of the deepest parts of this impact basin – with unusually great visibility – have now been acquired with the High Resolution Stereo Camera (HRSC), operated by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) on board ESA’s Mars Express spacecraft.
Record cold temperatures on Earth are far from the low point on a comet formed from ice and dust. Researchers using the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) on board ESA’s comet rendezvous spacecraft, Rosetta, have determined that the average temperature on Comet 67P/Churyumov-Gerasimenko is a mere minus 70 degrees Celsius. This is where, in November 2014, the lander Philae – constructed and operated by a consortium led by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) will touch down. “At this temperature, the surface of the comet is not completely covered with a layer of ice, but with dark, dusty material,” says DLR planetary researcher Gabriele Arnold, who heads the German scientific contributions to this experiment. The temperature was measured during Rosetta’s approach to the comet, where it is due to arrive on 6 August 2014.
Less than 2000 kilometres separate the ESA orbiter Rosetta and the Philae lander from their destination, Comet 67P/Churyumov-Gerasimenko. Images acquired with the OSIRIS camera system already indicate what lies ahead for the orbiter and lander upon arrival: "The surface seems pretty rough. We will have to wait to determine whether the visible depressions are impact craters or structures produced by cometary activity," says Ekkehard Kührt from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). The comet researcher is involved in the acquisition of data by the OSIRIS camera and is also responsible for data analysis. Another image taken by the camera shows that a cloud of dust, the coma, enshrouds the comet. “As we draw closer to Churyumov-Gerasimenko, the other instruments used in the mission will provide us with interesting insights into the interaction between the dust and the surrounding gas.”
Tough, resilient and able to survive in the most inhospitable regions on Earth –now, they are being asked to show their strength in a space environment as well; blue-green algae (cyanobacteria of the genus Nostoc) and biofilms (deinococcus geothermalis) will depart for the International Space Station (ISS) at 23:44 CEST on 23 July 2014 on board a Progress spacecraft.
Comets have irregular and rather potato-like shapes – this is a well-known fact. But the comet 67P/Churyumov-Gerasimenko, on which the Philae lander is scheduled to descend in November 2014, has an unexpected shape.