The Longest Chase in History Has Been Won

10 years and 4 billion km later, the ESA has caught up with a comet

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Head Image
© 2017 ESA

Comets, like the one which may have wiped out the dinosaurs, pose a huge threat to humanity, but yet, even in the modern day, humans know very little about them. This is all set to change though in the coming months, with the arrival of the European Space Agency’s (ESA) Rosetta probe at the awkwardly named comet ‘67P/Churyumov–Gerasimenko’.

Rosetta was launched over 10 years ago, and has slowly been building up speed to catch up with this comet. In order to achieve this, the probe did several bypasses of the Earth and other planets utilizing the ‘gravitational slingshot’ effect to increase its speed to over 31,000km/h. After travelling more than 4 billion km, Rosetta caught up with the comet yesterday, roughly halfway between the orbits of Mars and Jupiter.

Close up image of the comet 67P/Churyumov–Gerasimenko - © 2014 ESA

Currently, the probe is just 100km away from them the comet - a distance which is miniscule in astronomical terms - however over the coming days it will continue to move closer. Eventually it will move into a stable orbit around the comet, at a distance of roughly 30km .

From there it will carry out a number of detailed scientific experiments. These include detailed imaging equipment to beam back unprecedented pictures of the surface of a comet, as well as spectroscopy equipment which can measure the chemical composition of the comet. In addition, the probe will use radar and infrared imaging techniques to see under the surface of the comet and understand its core depths.

Alongside this equipment, Rosetta is also carrying a separate probe called Phillae which will land on the surface of the comet itself. As there is only a very small amount of gravity generated by the comet, Phillae will shoot harpoons into the comet in order to attach itself to the surface. There it will undertake further experiments and also beam back the first ever images from the surface of a comet.

Stay tuned - in the coming months we will hear and see much more about 67P/Churyumov–Gerasimenko.