Wednesday, March 23, 2016

Colloquium: Pluto and New Horizons

We had an excellent colloquium here today from John Spencer, one of the investigators on the New Horizons mission to Pluto.   Amazing stuff - if you ever get the chance to hear a talk by one of the mission members, don't pass it by.  A few facts that were striking:

  • The ambient surface temperature on Pluto is something like 40 K, basically because of the slow release of energy from residual radioactive material in there.  I guess that makes it too warm for the Outsiders, so we'll just have to wait longer to purchase a hyperdrive.
  • The surface of much of Pluto is geologically young - there seems to be something like a "nitrogen cycle" analogous to the earth's water cycle, whereby nitrogen ice sublimes, precipitates out on km-tall water ice mountains, and eventually flows in glacial form back down to nitrogen ice seas.
  • The New Horizons spacecraft was the fastest thing ever launched directly from the earth's surface, and it passed the moon within 9 hours after launch, having already been boosted to solar escape velocity.  (It's slower in the end than Voyager 1 and 2 because those spacecraft got close gravity assists from both Jupiter and Saturn.)
  • Pluto's moons other than Charon are, well, complicated.  Their rotational axes are nearly in the plane of their orbit about the Pluto system barycenter, and they're not all round, so they rotate and interact in complicated ways.
  • Space is big.  Really big.  You just won't believe how vastly hugely mindbogglingly bit it is.  I mean, you may think it's a long way down to the road to the chemist's, but that's just peanuts to space.


DanM said...

But one should always know where one's towel is.

Abhi Abhi said...

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