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| NASA photo of Pluto |
It has been an exciting week for space
nuts. In some respects the biggest news-grabber was the discovery of
“Earth 2.0”, a planet orbiting a yellow dwarf star a little
larger than our sun, in the Goldilocks zone. It's fourteen hundred
light years away, so we won't be visiting soon, but although I'm not quite as excited as some, the discovery adds weight to the already
impressive argument that we can't possibly alone.
Personally, I'm much more excited about
the data from Pluto.
I'm not a scientist, just an interested
spectator. I was expecting a barren, frozen rock rather like our own
moon, swinging around the distant sun in its wildly eccentric orbit
that sometimes means Pluto is closer to the sun than Neptune. I was
wrong. Frozen, sure. But just a rock? Uh-uh. Pluto has an atmosphere.
Pluto is not covered in impact craters – which means it is
geologically active. Pluto has canyons, and Pluto has solid, water
ice mountains as high as the Rockies. All this on a sphere smaller
than Earth's moon. Exactly what size is one of the many things
NASA's New Horizon probe has been able to calculate, as
reported here. And that's one of the things that interests me. Our moon has negligible atmosphere; Pluto's can be measured. It seems that heart-shaped thing is a
glacier. There may be organic molecules on the surface. This
article on Space.com gives a great, potted explanation of what
has been discovered so far.
The reason I find all this so
fascinating is mainly because of the water ice, and the organic molecules.
It has been speculated that Earth's
water came from asteroids. Pluto is the largest known object in
the Kuiper belt, the source of comets and asteroids. Perhaps just
such a body collided with the early Earth, contributing its water and
its organic molecules to the primordial mix?
I watched and rewatched the footage
which Voyager sent back to Earth during its encounters with Jupiter,
Saturn, Uranus and Neptune back in the eighties and nineties. Until
now, that data was all the scientists had to play with. They learned so much about the outer planets from that data and it still
forms the basis of many of their theories. The New Horizons mission
has answered some questions and raised many others. The Dawn comet
mission is set to send back more data as the host comet plunges
towards the sun. And Kepler continues to discover more exoplanets.
Meanwhile, work is proceeding on the James
Webb space telescope, set to replace Kepler. Who knows what it
will discover?
It's an exciting time to be alive.
It was, indeed, a very exciting week. Loved all the Pluto coverage and commentary, but getting to see what this distant body and her moons really look like was an amazing experience. I'm excited about Earth2, but 500 light years distance is still way beyond our ability to reach with current drive systems. Maybe now that we know it's out there--and possibly millions of others like it--there will be more of a push to develop FTL or so-called "warp" drives and "skip" communications so that someday we can send a probe to Earth2 or its equivalent--like we did to Pluto--and still see the results in the lifetime of the research teams.
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