Microlensing Uncovers Earth-Like Planet 263
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."
Re:Oh, Rebecca... (Score:3, Interesting)
Re:Wait... (Score:3, Interesting)
Mercury, Venus, Mars, and Pluto are all "earth-like" planets.
Well... Pluto is more like a large comet.
I helped set up some of their computers (Score:4, Interesting)
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Since then, they have built their own new 1.8m telescope, and likely replaced the camera, so the above information is out of date.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.
Re:Because it's small and rocky. (Score:5, Interesting)
Re:Wait... (Score:5, Interesting)
It's so close to absolute zero that most chemical reactions dont' happen there. The chance of life forming is probably next to nothing.
Re:Because it's small and rocky. (Score:3, Interesting)
Re:Wait... (Score:5, Interesting)
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.
Re:Oh, Rebecca... (Score:5, Interesting)
Re:I helped set up some of their computers (Score:2, Interesting)
The communication technique - reading and writing shared files - was designed for a 'LANtastic' network under DOS in 1989. I knew we wouldn't be using DOS or LANtastic for long, and wanted something that was simple, and would transfer well to different systems.
Shortly afterwards we moved away from Turbo Pascal under DOS (to Virtual Pascal under OS/2 :-), and started using a MySQL server for communication - I think the New Zealand 61cm is still using the original DOS code, although the new 1.8m is a different deal entirely. Since 1998 or so, everything I've written has been in Python, and I don't miss the Pascal at all...
Andrew Williams (one of the authors on the planet discovery paper)
Science is not law (Score:3, Interesting)
There is really no evidence either for- or against it. The objective standpoint is that we just don't know. It may be scary to have nothing to hold on to, but we should grow more comfortable with it since it will benefit us in the longer run. The wise man knows he don't know.
There are indications that with our present knowledge, we can't model life to fit those conditions, but we also know scientists have been surprised before, to find life in the most harsh conditions on earth. However, we have nothing to conclude with. Since history has shown science to be wrong on all accounts, it's not likely to be all right now either. In all of science there is always room for progress of understanding and developing from our current crude models in all areas of science.
Likely, our very fundamental models will have to change, and this will broaden understanding even more. Just like the relativity model and quantuum mechanics have revolutionized hi-tech science and manufacturing in the last decades.
As everything else argued over, it depends of your definition of life. Are viruses life, or just self-replicating molecules?
The "laws of physics" are not some laws constraining our universe, it's a model used by humans as an attempt to understand what's going on. To use it to litterally mean "laws", then dogma is created. This will only serve to hinder our progress of knowledge and discovery since it is constraining our consciousness.