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Rosetta has Arrived at the Comet / E-ELT Gets off the Ground
B횋N횋DICTE HUCHET
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[Reproduced from the e-EPS]

Rosetta has Arrived at the Comet

B횋N횋DICTE HUCHET

"We are delighted to announce finally 'we are here'," says Jean-Jacques Dordain, ESA's Director General. After 10 years of travelling through the solar system, the ESA's Rosetta spacecraft began its maneuver to orbit the Comet 67P/Churyumov-Gerasimenko on 6 August 2014. The first images of the Rosetta's rendezvous with the comet were presented during an event held at ESA's Space Operations Centre, ESOC, in Darmstadt, Germany, on the same day.

Named after the Rosetta Stone, which was discovered in 1822 and whose engravings have helped to understand hieroglyphs, the Rosetta spacecraft was launched in 2004. The trajectory to reach the Comet 67P/Churyumov-Gerasimenko is one of the most complex ever planned: benefiting from gravity-assisted flybys of Earth and Mars, Rosetta finally passed over Saturn, sending to Earth astonishing pictures of asteroids in that area. After Saturn, in order to save energy, the spacecraft was shut down, travelling alone in space. After a 2-year sleep, Rosetta woke up in January of this year when the satellite's 11 science instruments and 10 lander instruments were reactivated. Observations of the comet have begun and trajectory adjustments were needed to match the targeted comet. J.J. Dordain complimented the ESA's engineers and scientists as the best drivers ever.

HOW TO ORBIT A COMET

The 6 August 2014 is hailed as the end of the journey of Rosetta, when orbiting maneuver began. After 22 min of waiting, which corresponds to time needed by the signal to travel the 405 million kilometers from Rosetta to Earth, William Shatner, alias Captain James T. Kirk from Star Trek, summarized the situation: "Everything within normal parameters, Capt'n".

"Arriving at the comet is really only just the beginning of an even bigger adventure," said Sylvain Lodiot, ESA's Rosetta spacecraft operations manager. As Rosetta approached the comet, observations have already revealed an unexpected "duck-shaped" nucleus. Of course, more than a picture of the comet is expected from the ESA mission. Temperature measurements, gas detections, activity observations will continue as Rosetta orbits the comet. Collected data will be used to explore the origin of water on Earth, phenomenons from of the early Universe, and much more.

A robotic lander, named Philae after an antic Egyptian obelisk, is expected to land on the comet in November this year. "After landing, Rosetta will continue to accompany the comet until its closest approach to the Sun in August 2015 and beyond, watching its behaviour from close quarters to give us a unique insight and real-time experience of how a comet works as it hurtles around the Sun," says Matt Taylor, ESA's Rosetta project scientist.

J.J. Dordain concludes: "Europe's Rosetta is now the first spacecraft in history to rendezvous with a comet, a major highlight in exploring our origins. The discoveries can begin."

 

E-ELT Gets off the Ground



Fig. 1: Artist's impression of the E-ELT.

On June 2014, an explosion disturbed the silence of the Acatama Desert in Chile. Part of the 3000-metre peak of Cerro Armazones was blasted away in order to prepare a level platform that will host ESO's European Extremely Large Telescope [E-ELT], the largest optical/infrared telescope in the world.

The Atacama Desert is one of the favorite places for astronomers because of its exceptional conditions: the extremely arid mountain region, that is far away from any source of light pollution, offers a clear sky most of the time. This environment, chosen as the location for the future E-ELT, will also present new challenges for the construction of the telescope and its platform. Over the next 10 years, a road needs to be built and both the sun and the lack of water cannot be ignored while the numerous pieces of the telescope will be assembled. Monitoring systems will be installed at the Paranal observatory, 25 km away, which has served to host scenes of the James Bond movie, Quantum of Solace. E-ELT will not act as a lonely secret agent and is expected to work in a team with space telescopes, such as Hubble, by offering complementary data.

Thanks to its 39 m-wide mirror, the telescope will be able to provide spectra of exoplanets, currently known as a 2-pixel picture. During the last decade, a tremendous number of exoplanets have been discovered that are not distinct from solar planets. The data gathered by E-ELT will allow astronomers to explore the atmosphere of some of these exoplanets.

The first observation from E-ELT is planned for 2024.

 

 
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