This spectacular image of our home planet was captured by Europe’s Rosetta probe as it made its third and final flyby of Earth, before heading towards a comet. The outline of Antarctica is visible under the clouds in the illuminated crescent. Pack ice in front of the coastline caused the very bright spots on the image.
It was taken by the-board camera OSIRIS yesterday, from a distance of 393,000miles. The picture combines three images taken with orange, green and blue filters and has a resolution of 7.5miles/pixel.
Rosetta made its closest approach to Earth at 7.45am (GMT) today at an altitude of 1,540miles – which is inside the orbits of geostationary telecoms satellites. However, European Space Agency (ESA) scientists said Rosetta would be extremely difficult to spot from the ground and only large telescope could pick up the faint fast-moving object.
The fly-by will give Rosetta the gravitational boost it needs to speed towards Jupiter, via the asteroid Lutetia in July 2010. The probe will hibernate for the coldest part of its epic journey from mid 2011 to spring 2014.
If all goes well it will respond to a ‘wake-up call’ and chase down the comet 67P/Churyumov-Gerasimenko in May 2014. The successful swingby was confirmed at 8.05am (GMT) when mission controllers re-established contact with Rosetta via ESA’s station in Spain.
The comet chaser has now flown 2,800million miles of its 4,400million mile journey, passing Earth three times and Mars once. Some of Rosetta’s instruments have been on since early November, performing imaging and atmospheric observations of Earth, as well as looking for water on the Moon.
The 10ft by 6.5ft craft is packed with scientific instruments to study the ball of ice, rock and dust. Rosetta will firstly orbit the 2.5mile comet and make a detailed map of its surface. It will then release a washing-machine-sized lander called Philae, which will anchor onto the comet as it sweeps into the inner Solar System.
As the speeding comet heads towards the Sun, the radiation will cause the ices on the comet to turn straight from a solid into a gas. Material will be ejected at supersonic speeds in the form of a tail. The Rosetta orbiter and Philae lander will record the process and send data back to Earth.
The ambitious mission will have taken 10 years once completed. Rosetta is named after the Rosetta Stone, a stone tablet discovered in 1799 by Napoleon’s forces as they invaded Egypt. Just as the Rosetta Stone enabled the hieroglyphs to be deciphered, scientists hope that the Rosetta mission will provide some clues to help them understand more about our Solar System.(daily mail )
