Comet 67P, robot lab Philae's alien host, nears Sun
PARIS — A comet streaking through space with a European robot lab riding piggyback will skirt the Sun this week, setting another landmark in an extraordinary quest to unravel the origins of life on Earth.
Scientists hope the heat of perihelion – when the comet comes closest to the Sun in its orbit – will cause the enigmatic traveller to shed more of its icy crust.
If so, it could spew out pristine particles left from the Solar System's birth 4.6 billion years ago, they believe.
And if Comet 67P/Churyumov-Gerasimenko undergoes this dramatic change, Europe's Rosetta spacecraft will be orbiting nearby, ready to pounce on any clues of how our star system came into being.
"This is the time most of the action happens," said European Space Agency (ESA) expert Mark McCaughrean of the weeks-long peak of comet activity.
The ancient celestial voyager will reach its closest point to our star – some 186 million kilometres – at about 0200 GMT on Thursday, before embarking on another 6.5-year egg-shaped orbit.
Things have been heating up for weeks, with gas and dust blasting off the comet's surface as solar heat transforms its frozen crust into a space tempest.
This is "the greatest opportunity to catch material and analyse it if you're looking for rare species of molecules," especially organic ones, McCaughrean told AFP.
"We want to look at the more pristine material that might come out" from beneath the layer of icy dust stripped from the surface.
Most exciting would be if the duck-shaped comet's "neck" – which hosts a 500-metre crack – were to break in two to reveal the raw insides.
"That's really the Holy Grail... to see the interior of the comet," said McCaughrean, though most scientists believe a break-up is unlikely this time around. — AFP