Rosetta has reached the Stone!
Rosetta has arrived! After a ten-year journey from Earth that involved whizzing round a few planets, not to mention five orbits of the Sun, to get up sufficient speed, the space probe launched in 2004 by the European Space Agency has finally caught up with Comet 67P Churyumov-Gerasimenko – which is admittedly not as memorable a name as Halley, or even Swift-Tuttle!
The comet, which was originally discovered in 1969 by the two Ukrainian astronomers after whom it is named, was identified some years ago as a suitable candidate for close inspection as it headed towards the Sun from the furthest reaches of the Solar System.
Comets are pieces of rock that have been unchanged since before the planets were created some 4.6 billion years ago. They are therefore of considerable interest to astronomers who want to know how the Solar System evolved and what its fundamental building blocks look like. Some scientists believe that the water on Earth came from comets, as did the building blocks for life. The Rosetta mission might just be able to answer that question.
Rosetta and Comet 67P are now hurtling along together, 500 million miles away. The plan is for Rosetta to orbit the comet, making many scientific measurements and analyses as it does so, while also looking for a suitable landing site for a small probe.
The comet is only 2.5 miles across at its widest point and therefore has extremely low gravity. The danger is that a probe might simply bounce off once it tries to land, so it will send ‘anchors’ into the surface to keep it in place while samples are taken and analysed.
Pictures that have already been transmitted reveal Comet 67P to have an unusual shape. It looks like two lumps of rock that have been fused together and it has been likened to a ‘rubber duck’ in its overall appearance.
Comets have been described in the past as ‘dirty snowballs’ in the belief they contain a considerable amount of ice. However, an initial inspection of 67P, made during Rosetta’s approach, shows that its temperature of minus 70 degrees C is much warmer than expected. This would indicate that the surface is more dusty than icy.
The astronomers and scientists who are managing the mission are getting understandably excited about what the future holds in terms of what they might learn about 67P. This is a highly complex and ambitious mission (not to say expensive!) so good results are being looked for that will, with any luck, answer some very old and pertinent questions.
( For the attention of LoudMan )
Image Credit » DLR. Licensed under the Creative Commons Attribution 3.0 Unported licence.