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Rosetta Spacecraft Catches Comet Eruption 42

An anonymous reader writes: On March 12, the Rosetta spacecraft was imaging Comet 67P/Churyumov-Gerasimenko from a distance of 75 kilometers (46 miles) and by pure chance it spotted an eruption of dusty material from the shaded nucleus. Long-duration spacecraft are essential if we are to fully understand the evolution of a comet as it gradually heats up during its approach to the sun. And it just so happens that Rosetta is always in orbit around 67P's nucleus, ready to spot any transient event that could erupt at any time on the surface

This latest event focuses on the comet's shaded underside. It is assumed that some sunlight slowly heated an outcrop, providing enough energy to sublimate subsurface ices, ejecting vapor and dust as a jet. The transient jet was imaged and measured by Rosetta's scientific imaging system OSIRIS. There is also the possibility that a wave of heating passed through the icy material, eventually producing a more explosive jet event.
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Rosetta Spacecraft Catches Comet Eruption

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  • the duck farts

  • "By pure chance," you say? If the damn thing was designed to orbit and observe, how is it pure chance that at some point we saw something interesting?
  • maybe i spend too much time...well, you know....
  • by YrWrstNtmr ( 564987 ) on Tuesday April 21, 2015 @09:46PM (#49524839)
    "And it just so happens", that is was designed to be in orbit around this comet. It wasn't just shot up at random, and "just happened" to fall into orbit around this comet.

    Who writes this crap?
  • by Anonymous Coward

    Does the sudden change in the mass from the melt in the comet and the effect of the jets change its velocity and trajectory?

    • by Jiro ( 131519 )

      Basically, yes. This is what's referred to as "non-gravitational forces" (you can Google the term, but Wikipedia doesn't seem to have an article). It makes it harder to predict the orbits of comets under some circumstances.

  • pure chance? (Score:4, Insightful)

    by bloodhawk ( 813939 ) on Wednesday April 22, 2015 @02:42AM (#49525777)

    If I spend 24x7 staring in your bathroom window you don't call it "pure chance" that I happened to see you taking a shower.

  • Here's hoping one of these jets doesn't hit Rosetta and send it spinning off into deep space like Buck Rogers.
    • by cusco ( 717999 )

      Emily Lakdawalla's blog has quite a bit of good information about what's going on. With pretty pictures. []

      More problematic than jets coming from the comet (which are pretty diffuse and low speed in reality) is that twice passing comet particles have come close enough to be mistaken for the stars that the spacecraft use to orient themselves. Since it's moving past so fast the spacecraft assumes that something is wrong and puts everything in Safe mode.

  • Can we finally admit the Electric Universe guys are at least right about comets? This "jet" is coming from the dark side of the comet? Doesn't seem likely.

    • by cusco ( 717999 )

      Well, if the Electric Universe guys had been correct about even a single prediction or observation since Velikovsky and company came up with it it might be easier to accept. For now it's just quackery, of the same level of science as homeopathy or phrenology.

    • by Maritz ( 1829006 )
      I'm afraid Electric Universe is looking about as correct as the turtles all the way down theory.

No problem is so large it can't be fit in somewhere.