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Rosetta: The wild wild world of comet chasing

About the author

Described by the Times as “the world’s most enthusiastic man” and the Daily Mail as someone whose “wit and enthusiasm can enliven the dullest of topics”,  Quentin is a broadcaster, film critic and author best known for presenting the UK's most listened to science programme, The Material World on BBC Radio 4 . It’s “quite the best thing on radio”, according to Bill Bryson. You can find him on Twitter at @materialworld

  • Historic mission
    The ESA spacecraft Rosetta is about to chase comet 67P/Churyumov–Gerasimenko – before encircling it and launching a lander to inspect its icy bulk. (Nasa)
  • Deep space snowball
    The comet 67P/Churyumov–Gerasimenko has a diameter of four kilometres, and takes nearly six-and-a-half years to cover its current orbit. (ESA/Nasa)
  • Hard landing
    Rosetta’s lander will fire harpoons to attach it to the comet, before analysing samples of the space rock’s frozen surface. (Astrium/E Viktor)
  • Stardust to dust
    Rosetta is not the first probe to get close to comets; in 2005, Nasa’s Stardust visited two, as well as an asteroid. (Nasa)
  • A date with Eros
    Nasa’s (Near) Shoemaker mission in 2001 was the first to actually land on a comet or asteroid, latching itself to the asteroid Eros. (Nasa)
  • It came from the stars
    Deep Impact was one of two blockbuster films of 1998 dealing with the premise of a huge, Earth-threatening asteroid. (Paramount Pictures)
  • Shooting stars
    Deep Impact’s rival in the big screen disaster stakes was Armageddon, a ludicrously plotted epic starring Bruce Willis as a drilling engineer tackling an asteroid. (Buena Vista)
  • Brace for impact - DI
    Both films saw humanity ultimately triumph over the space rocks, though Deep Impact’s body count – from a huge chunk hitting the Atlantic – was immense. (Paramount Pictures)
  • Uncertain rendezvous
    The ship will be roused from slumber in the next few days, though when it makes physical contact with the comet is unclear; scientists intend it to be by the end of 2014. (Nasa)
With the Rosetta spacecraft poised for a very close encounter with a comet, Quentin Cooper wonders how much have missions been inspired by Hollywood?

It’s time for humanity to have a close encounter of the comet kind. The Rosetta spacecraft is finally about to wake up and start to chase down its prey after years of pursuing it across the cosmos. The prey in question is the catchily named comet 67P/Churyumov–Gerasimenko, which – if the probe is roused from deep space hibernation in the next few days and all goes to plan – Rosetta will slowly catch up with, then encircle and study before putting a robotic lander on the comet’s surface before the end of 2014.

It’s claimed the European Space Agency (ESA) probe, launched in 2004, is the first mission designed to orbit and land on a comet. It’s no mean feat, although over a decade ago Nasa’s Near Earth Asteroid Rendezvous (Near) Shoemaker spacecraft did just that with the much more memorably named asteroid Eros – going into orbit around it on 14 February 2000, and landing on its surface on 12 February 2001. If only they’d held back by two days it could have forever linked romance with unmanned space exploration.

So why go to this time and trouble, not to mention expense – Rosetta has already cost around $1bn – to get up close and personal with yet another bit of space rock? As well as Near’s soft landing on an asteroid, we’ve also had assorted missions like ESA’s Giotto (which flew by Halley’s Comet in 1986), Nasa’s Stardust (which sidled up to two comets and an asteroid) and most famously Nasa’s 2005 Deep Impact which, like a playground bully, smashed defenceless comet Tempel 1 in its ‘face’. The official reason for firing an 820lb (372kg) lump of copper at the comet was to learn about its composition by analysing the crater and debris (unfortunately, so thick was the dust cloud thrown up by the collision that the crater was largely obscured). But after growing up with a sci-fi surfeit of laser cannons, photon torpedoes and ray guns, I’ve a feeling many will have backed the mission just because it went into space and zapped something.

Armageddon it

Being called Deep Impact seems to provide a clue as to why we keep sending probes to asteroids and comets: was a publicity-conscious Nasa taking inspiration from Hollywood? It was launched only a few years after the 1998 blockbuster Deep Impact – a global smash about a huge comet poised to cause a global smash, and the risky mission to blow it up with nukes. The film came out the same summer as the similarly themed, more successful and far more ludicrous Armageddon, where Bruce Willis and his gang of oil drillers are hired by Nasa to destroy a huge asteroid before it wipes out life on Earth (it apparently being easier to train Bruce and company to go into space than to teach astronauts to use explosives).

Naming a genuine mission “Armageddon” would definitely have been one small step too far. But having a real spacecraft called Deep Impact that – just like in the movie – had the goal of (partly) blowing up a comet feels more like a brilliant bit of populism from Nasa.

Officially at least, though, the story isn’t true. Nasa maintains that their Deep Impact was in the works long before the film, and that the shared name is just coincidence. In fact the far more revealing name is Rosetta, which comes from one of the treasures of the British Museum. The Rosetta Stone is a 2,000-year-old Egyptian decree inscribed not only in hieroglyphs but also Ancient Greek (as well as the more everyday Egyptian demotic script), which finally enabled linguists to decipher hieroglyphs and the time of the Pharaohs after a millennia of bafflement. Comets and asteroids aren’t quite the mystery hieroglyphs used to be: we already know the basics about them. But we have only just scratched the surface – literally in the case of Deep Impact – and the more missions like Rosetta can unearth about these planetary building blocks the better we will grasp how our solar system formed and works today.

Rosetta was originally targeted at an entirely different comet, but a launch delay forced the switch to 67P/Churyumov-Gerasimenko. If a suitable landing site can be identified, and the twin harpoons can prevent the Rosetta’s robotic lander from bouncing off the small and therefore low-gravity comet, then the instruments on board – including spectroscopes and radar – as well as those on the main spacecraft should provide unprecedented insights into the nucleus, chemistry and behaviour of these icy bodies.

No-one’s quite sure what Rosetta will bring to light, but they can feel reasonably confident it won’t go the way of another comet mission, the one in 1985 sci-fi horror movie Lifeforce. Director Tobe Hooper’s follow up to Poltergeist begins with the crew of a Space Shuttle investigating Halley’s Comet and finding a huge alien spaceship hidden in its tail. It ends – after a remarkable amount of gratuitous nudity – with a zombie plague that destroys London.

Suddenly Armageddon doesn’t seem quite so ludicrous.

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