We Wouldn’t Be Here Without The Moon

Or so Azimov wrote. We need it to stabilized the earths rotation, so that our poles don’t wander all over the place. We also need the tides and the somewhat thiner atmosphere the moon’s proximity gives us.

He was probably right, but there’s many “just so” things about the universe we find ourselves in. If you change them, often by surprisingly small amounts, the results is a universe that is inconsistent with our own existence.

So, does life, which we all want to believe just has to be out there somewhere in that really, really big universe, depend upon a planet having a large moon?

Not really, but certainly intelligent life, something smart enough to build and use radio, let’s say, to communicate with us would certainly have an easier time of it if it’s home planet had a large moon.

[If you object to limiting our question to radio-using intelligent life, consider that at least that lets us find something able and even willing, by using radio, to communicate with us – which I admit is sort of like looking for the missing car keys by the street light, because you certainly won’t find them in the dark…]

If we’re interested in knowing better how good our chances are of finding E.T.s, then we’re going to concern ourselves with knowing how likely a planet like the Earth is to having a large moon.

It turns out that it’s somewhat less likely than we thought up to now.

New observations made by NASA’s Spitzer Space Telescope of stellar dust clouds suggest that moons like Earth’s are—at most—in only 5 to 10 percent of planetary systems.

“When a moon forms from a violent collision, dust should be blasted everywhere,” said Nadya Gorlova, an astronomer at the University of Florida in Gainesville who analyzed the telescope data in a new study. “If there were lots of moons forming, we would have seen dust around lots of stars. But we didn’t.”

There’s more here, and amonst the supercilious nonsense, some interesting discussion at Slashdot, especially about Azimov.

My take is that it’s interesting that the estimates of the chances of finding intelligent life elsewhere in the universe is monotonically decreasing (never increasing). When Fermi asked his famous, paradoxical question “Where are they?” he was noting that there may be an obvious proof that we are unique in the galaxy (the proof being that the galaxy is old enough, and communication is easy enough, that the odds are pretty darn good that we should be hearing from someone else by now). This observation by Spitzer makes it just that much harder to believe that we’re not unique.

Scientists hate that idea, because it questions their assumption of mediocrity – that we are not specially situated in the universe. One way or another, that can only be an assumption.

Explore posts in the same categories: Astronomy, Science, Space

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