Say 'freeze'! Rosetta snaps images of its icy target as it prepares to become the first spacecraft to orbit a comet
comments
Esa's comet-chasing Rosetta spacecraft is nearing the most important stage of its mission as it prepares to become the first probe to orbit a comet.
It is now just 27,000 miles (43,000 km) away from Comet 67P/Churyumov-Gerasimenko, with its arrival scheduled in the coming weeks.
And by 6 August controllers at Esa hope that Rosetta will have entered orbit, while a few months later it will unleash the Philae lander onto the surface - the first such landing ever attempted.
Esa's Rosetta spacecraft is now within 27,000 miles (43,000 kilometres) of its comet target. In this series of images, taken by Rosetta's scientific imaging system Osiris in late June, the Comet 67P can be seen to be rotating, giving the first tantalising hints of its shape. It completes one rotation in just over 12 hours
'Rosetta completed the fifth in a series of ten rendezvous manoeuvres required to ensure the spacecraft's arrival at the comet on 6 August,' said Esa in a blog post announcing the spacecraft's close approach.
THE ROSETTA MISSION
Rosetta, named after a block of stone that helped archeologists decipher ancient Egyptian hieroglyphs, will seek to help scientists unlock the composition of comets and thereby understand more about the origins and evolution of our solar system.
The probe was launched in 2004 and has since travelled around the sun five times, picking up energy from Earth and Mars to line it up with its final destination: Comet 67P/Churyumov–Gerasimenko.
For the coldest, loneliest leg of the mission, as Rosetta travelled out towards the orbit of Jupiter, the spacecraft was put into deep-space hibernation.
Rosetta will enter orbit around the comet in August, before putting its Philae lander onto the comet's surface in November.
While in orbit it will perform extensive analysis of the comet's composition, which will provide us with an insight into the history of the solar system and discover the origin of comets.
Rosetta is firing its thrusters to cut by almost two thirds the speed with which it's hurtling towards the comet.
The agency says Wednesday's burn is the first of four before Rosetta comes within 62 miles (100 kilometers) of the comet in early August, beyond the orbit of Mars.
The final rendezvous requires two more precision maneuvers.
The probe, launched a decade ago, will spend time observing 67P before dropping a lander onto its icy surface in November.
The comet is about 2.5 miles (four km) long and orbits the Sun every six-and-a-half years.
Once at the comet Rosetta will follow it on its journey around the sun, performing extensive studies of the coma and the surface.
And in November it will release the Philae lander, which if successful will be the first vehicle ever to land on a comet.
The spacecraft's speed will be slowed in order to remain in orbit, bringing it to roughly about walking pace relative to the comet.
The Rosetta spacecraft launched in 2004 on a mission to study comet 67P/Churyumov-Gerasimenko (artist's illustration shown). It will rendezvous with the comet later this month before entering orbit in August, becoming the first spacecraft to orbit a comet
In November of this year the Philae lander will be sent to touch down on the surface of the comet (artist's illustration shown), which will be the first landing ever performed on a comet. Here, harpoons will be fired into the surface to keep it anchored while it studies its surroundings
The comet is heading towards the sun, so as it nears the star it will begin to melt more.
Even though it is still more than 370 million miles (600 million kilometres) from the sun - more than four times the distance between Earth and sun - its surface has already started to warm, causing its ices to turn to gas and escape from its rock-ice nucleus.
As the gas escapes, it also carries a cloud of tiny dust particles out into space, which slowly expands to create the coma.
The warming will continue as the comet moves closer to the sun and activity rises, and pressure from the solar wind will eventually cause some of the material to stream out into a long tail.
This will give Rosetta some fascinating opportunities to observe the comet's emissions and find out more about its composition.
Rosetta and the comet will be closest to the sun in August 2015, when they will be between the orbits of Earth and Mars.
On 25 Feb 2007 The Rosetta spacecraft returned this stunning image of Mars as it flew past the red planet on its way to the comet. The picture was taken by an imaging instrument on the Philae lander at a distance of 620 miles (1,000 kilometres). Below the solar array an area close to the Syrtis region is visible on the planet's disk
Put the internet to work for you.
0 comments:
Post a Comment