Rosetta: Riding a ‘bucking bronco’ in space

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The excitement is mounting. We're going to be talking about comets an awful lot in the coming months.

First of all, we have Comet Ison to enjoy. We hope.

This mountain of ice and dust has come hurtling in from the outer Solar System and is about to swing around the Sun.

At closest approach on 28 November, it will be no more than 1.2 million km (800,000 miles) from our star's boiling surface.

The big question is: will it survive the encounter? "Sungrazers" like Ison very often just fall apart. But if it can remain intact, this "dirty snowball" will swing back out past the orbits of the inner planets, potentially throwing off huge streams of gas and dust.

The comet could appear as a great arc across the sky, no binoculars required. Then again, it might not. Comets are notoriously unreliable.

Written By: Jonathan Amos
continue to source article at bbc.co.uk

5 COMMENTS

  1. For those who have watched the sci-fi “Armageddon” this should be a robot version, looking at the comet’s surface, over an extended period.

    @OP – And come December, we’ll all have started looking forward to the space mission of 2014: Rosetta.

    This is the European Space Agency probe that was launched way back in 2004. It’s spent the past nine years working its way out to the orbit of Jupiter, to chase down Comet 67P/Churyumov-Gerasimenko.

    The plan is for Rosetta to circle and track this comet as it sweeps in towards the Sun.

    The big highlight, though, will be the deployment of the probe’s Philae lander. It’s going to try to lock down on 4km-wide 67P and ride it.

    How long Philae could withstand any outgassing as the ices heat up on approach to the Sun is anyone’s guess. Will 67P be a “bucking bronco”? –

    • Named after its 1969 discoverers Klim Churyumov and Svetlana Gerasimenko

    • Referred to as a “Jupiter class” comet that takes 6.45 years to orbit the Sun

    • Orbit takes it as close as 180 million km from the Sun, and as far as 840 million km

    • The icy core, or nucleus, is about 4km across and rotates every 12 hours
    • Its shape is reasonably well known (model above). There are three key active regions

    “Philae’s got screws and harpoons to hold it down,” says Dr Matt Taylor, the Rosetta project scientist.

    “I have to be confident we’ll succeed. We’ll be investing a lot of time before the landing trying to find the best place to put down.”

    Here’s a timeline for the key events:

    20 January 2014: Wake-up from hibernation
    Mid-March 2014: Check-out instruments
    21 May 2014: Major rendezvous manoeuvre
    6 August 2014: Arrive at Comet 67P
    27 August 2014: Start global mapping
    11 November 2014: Philae deployment (at about 450 million km from the Sun)
    13 August 2015: Perihelion - closest approach to the Sun (at about 185 million km from the Sun)
    31 December 2015: Nominal end of mission (although Esa is unlikely to switch off a working Rosetta)
    

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