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From National Geographic:
It’s Official: Pluto Is Even Weirder Than We Thought
Sure enough, that’s what the spacecraft found when it sped by the dwarf planet last July at more than 30,000 m.p.h.—a tortured, highly varied landscape that pointed to a living, geologically active world rather than an inert blob hovering at the frozen edge of the solar system.
Even now, three months after New Horizons’ close encounter, scientists are just beginning to get a handle on what’s going on with Pluto and it’s large, equally intriguing moon Charon. But what they know already, laid out in a new paper in Science, is impressive—and deeply perplexing.
Pluto appears to have been resurfaced (no craters) but
That would only be possible if Pluto had a source of heat other than the Sun, whose energy at a distance of about three billion miles is vanishingly feeble. More.
Well, everyone loves a good mystery. The public energy, interest, and money spent on exploring our own solar system is really paying off. And we can continue to do realistic missions around here too.
So sometimes one wonders about all the hoo-haw around supposedly Earth-like exoplanets, by comparison.
Why not spend the money closer to home where we can see it at work? There’s plenty of stuff to find out about our own neighbourhood.
See also: “Behold, countless Earths sail the galaxies … that is, if you would only believe …” :
In reality, even the rocky exoplanets (known as of early 2013) that are Earth-sized are not Earth-like. For example, the Kepler mission’s first rocky planet find is described as follows: “Although similar in size to Earth, its orbit lasts just 0.84 days, making it likely that the planet is a scorched, waterless world with a sea of lava on its starlit side.” As space program physicist Rob Sheldon puts it, Earth is a rocky planet but so is a solid chunk of iron at 1300 degrees orbiting a few solar radii above the star. In any event, a planet may look Earth-like but have a very different internal structure and atmosphere.” Could exoplanets support life that has a different chemical composition? Absent details about the composition, who knows? Despite all this, an Earth Similarity Index has been compiled, offered with the caution that life might also exist under unearthly conditions, a caution that renders the Index’s value uncertain. – Rob Sheldon
and
Don’t let Mars fool you. Those exoplanets teem with life!:
See also: Pluto has youthful ice mountains? So says the New Horizons flyby
File under: New category, Weirder than thought
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