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Microlensing Uncovers Earth-Like Planet
smooth wombat writes "Using a new technique called gravitational microlensing, a team of astronomers have discovered the smallest Earth-like planet circling a star 20,000 light years away in the constellation Sagittarius. Unfortunately the planet takes ten years to circle the red dwarf and has a surface temperature estimated at -220 C which means it's just a larger version of Pluto so the chance of finding life on this planet is essentially zero."
Back in about 1995, I was in Auckland finishing up my Princeton PhD, and travelled to the MOA telescope (a pre-existing .6m telescope) when they were setting up their new camera. I installed Linux on about 3 desktop computers in the dome. They had a rack-mounted Sun machine controlling the camera, and there was a pre-existing DOS computer which controlled telescope pointing.
A few points of interest/weirdnessess
MOA is a collaboration with Japanese, so all the Linux installs included Japanese language support, including Japanese xterm windows.
Communication between the Linux boxen and the DOS box was purely by creating/deleting files on a shared drive. E.g. the Linux box would put a file on the drive saying where to point, and then would busy-wait looking at the file until it disappeared, at which point it knew the telescope was now tracking the required location.
The camera would do 30 second exposures. The Sun box ran a little script to do an exposure, which would send commands to open the shutter, wait, close the shutter, and read the data. The exposure timing was done with a "sleep 30" command! I was *not* happy with that, but didn't convince people to change it.
Since then, they have built their own new 1.8m telescope, and likely replaced the camera, so the above information is out of date. I haven't had any involvement in the project other than that one trip.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
I don't see how it would necessarily be incredibly hostile. First off, they don't even have albedo figures for this planet, let alone information on how much greenhouse effect the planet has. Secondly, if this actually is a solid planet that is this massive, it should have ample internal radiological heating, so rough calculations from solar input adjusted by albedo aren't really accurate. Even if the surface is frozen, it should have warm subsurface layers. Ne?
Musk needs a safer hobby than Twitter. Fire juggling? Cage fighting? Solo hot air balloon trips?
I'd agree with you on needing so called perfectly earthlike conditions for life but... -220c is cutting it...
It's so close to absolute zero that most chemical reactions dont' happen there. The chance of life forming is probably next to nothing.
Hmmm... Pie...
How do we know there aren't certain forms of life for which -220C is like a warm, hunky-dory bath?
Actually, there are some good (but not conclusive) chemical reasons. Some of them came out in the recent discussions of why Titan might support life.
Now, -220C is abut 53K, which is pretty cold. Titan is about 94K, which doesn't sound much warmer to us, but it's actually nearly twice as "warm". At 94K, methane is a liquid, and it's also a solvent. It behaves much like water, though it's a non-polar molecule, so any biochemistry would be different from ours. In particular, methane is good at dissolving organic (i.e., carbon-chain based) compounds.
At 53K, methane is a solid.
All this is significant because it's reasonable to assume that complex life requires complex chemistry. At low temperatures, the only way known to do this is with carbon chains (though there has been speculation that at higher temperatures than ours, silicon could perform a similar role). And for biochemistry to work, most of the biochemicals should be in a liquid matrix, so they can move around and interact easily.
So a planet at 53K wouldn't be a very likely place to find complex chemicals with compex interactions. Everything interesting would be solid. At 94K, it's possible, with methane as the solvent substrate. At our body temperature, 310K, methane is a gas, but water is a liquid and a good solvent, so biochemistry works for us.
But you're right that this is all speculation, based on the only kind of life that we know. Science-fiction writers have contemplated life at other temperatures, but we have yet to find evidence of any.
A few years back, Robert Forward wrote a sci-fi novel, Camelot 30K, which is about the discovery of life on a Pluto-like planet in the Kuiper belt. The title comes from its ambient temperature, 30K, and the social order which is medieval. Being a good physicist, he explains at one point that the living creatures are all "warm blooded", with body temperatures arund 90K. This is so that their body fluids remain liquid. It turns out that they inhabit many of the Kuiper-belt planets, and have an interesting means of dispersal. Presumably they evolved a bit closer in, long ago, on a planet with temperatures somewhat higher. This may sound like a stretch, but our body temperature is about 30K above our planet's mean temperature.
Anyway, maybe some day we'll know more about what is possible. Maybe, as Forward imagined, we'll find out when we visit the outer reaches of our solar system. Or maybe not.
Most of the media attention to possible life is basically silly, and based on little more than speculation. If you want to be entertained by speculation without evidence, you're better off reading science fiction.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
If you've ever been to a place where liquid water doesn't exist as I have, you very quickly take on a different viewpoint. Water is normally, even on this planet, often a sand or a gravel, undifferenciated from any other mineral at a cursory glance. "Frozen liquid" in reference to water stops having meaning at about -30C because it simply doesn't exist naturally in that state. You start thinking of gasoline and oils as "frozen" or "thawed" instead. Titan gave us a glimpse of an strangely familiar world where water was the predominant mineral and methane was the liquid that rained down and formed oceans.