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Alien Atmosphere Hubbled
b-side.org writes "Yahoo! News has a story on yon giant hubble mirrorscope thingy locating an alien, mostly sodium, atmosphere. X10.com popunder ads also included free of charge." Mm....let's mix that atmosphere with water. T cuts in: This turns out to be the major discovery hinted at a few days ago.
Why are we just looking around? We have the technology! Let's at least go to Mars. Consider that eventually Earth will die. Sooner or later we must be prepared to go somewhere else. I think we should start now.
Also consider we live in an infinite universe. There are infinite worlds, and infinitly many of them can support life, and infinitly many of them DO support it. Infinity, think about it.
Allright. I'm going to rant a bit.
What possible good does the Drake Equation do? We are no where near being able to estimate accurately any of the terms in the Drake Equation. Even the Star Formation term (by far the term with the lowest errors) has gigantic uncertainty built into it. It seems ridiculous to try to make up an equation where you don't know any of the terms. Yes, I agree that it is facinating to consider the possibility of life elsewhere in our Galaxy, but applying an equation to this interest implies a level of knowledge that it just not there.
I mean, I can make up an equation to calulate anything I want, but if I don't know what the value of any of the terms are, what good is it to anyone?
I couldn't tell if you were experimenting with poor-man's cryogenics or looking for the orange sherbet.
Well, many people on Slashdot are full of nothing but hot air and yet we seem to consider them to be intelligent.
We're going to make information free Mr. Anderson, whether you like it, or not.
1) The sodium bit: It's not that the planet's atmosphere is mostly sodium, it's just that sodium is rather easy to detect as compared to other elements (we use it to identify stars all the time). Also, given the spectral coverage of STIS (the spectrograph used to make the measurement), Na was probably the only strong line they could go for in one setting.
2) Why this is a big deal: Yes, we know there are gas giants elsewhere, but that's not the point. It's more of a proof of concept that we can measure the properties of an atmosphere of a planet outside the solar system. Plop a more sensitive instrument up there and you can go for smaller planets....and hopefully find signatures of methane and oxygen...boo-yah.
3) The unexpected bit (from the astronomers point of view) Hubble found it. Hubble's great and all, but spectra is not it's bread and butter. Most of us in the astro community were betting on Keck to find this first since a 10 meter on the ground with larger spectral coverage kicks the crap out of a 2.5 meter (Hubble)
-------- The thought plickens....
The point is that this is a stepping stone. This particular planet and this particular atmosphere are totally irrelevent to anythign and everythign. What is importent is the developement of the TECHNOLOGY behind this discovery. The fact that we were ABLE to ditect it means we are going forward and may someday soon have a way to detect earth-like planets. Or other nifty stuff.
"Nobody writes jokes in base 13." - Douglas Adams
The Drake equation has one important factor missing from it: the "here-and-now" factor. The only part of the Drake equation with regards to time is the "lifetime" of communicating civilizations, or, specifically, "the length of time such civilizations release detectable signals into space" (space.com).
Wouldn't the simple idea be that if alien civilizations were technologically advanced enough and if they sent out detectable signals at all, then they would have to exist right now for us to detect them? The truth is that the vastness of our universe (throughout most of which we will never find "detectable signals" from within the next few million generations) makes the chances that other intelligent life exists fairly good. But the chances of us detecting them, them detecting us, or both detecting each other is fairly slim since we do not know if the time at which both civilizations are technologically able to do so coincides.
Consider this as well: signals take time to travel. Who's to say that if a civilization on the other side of our galaxy that existed 50,000 years ago but is extinct now ever had the opportunity to send out signals. What if there's intelligent life on an Earthlike planet orbiting Epison Eridani (only 10 light years away), but their civilization takes 500,000 years to become technologically adept enough to build detection or emitting devices? (Comparably, human life needed only 100,000 or so years to develop from animals that used simple tools to today's high-tech humanoids.)
Maybe we just need to quit debating and keep looking.UNIX: Find it, fsck it, forget it.
There's a better article in nytimes.com (registration required). The Hubble's spectrograph is detecting tiny traces of sodium in the planet's atmosphere as it transits between the star (its sun) and us. They set it to look for sodium, because that has the strongest spectrum lines of any element. The article didn't say, but I think these must be absorption lines where the starlight shines through the atmosphere of the planet, around the edges as it transits. I would assume it is ionic sodium -- you just plain don't find sodium in any other form.
The planet is Jupiter-sized, and close to it's sun, so the atmosphere is hot enough to melt copper. Not a good place to visit... But with the present methods for detecting extra-solar planets, any we can spot will be too big and too hot.
Mostly, planets are detected because their mass as they orbit makes the star jiggle just a little (the star and the planet orbit the common center of gravity -- which is still somewhere inside the star, but not the exact middle). The stars motion doppler shifts it's light, and so there is a periodic shift in the star's spectrogram. The bigger the planet is and the closer to the star, the more jiggle -- someone in another solar system looking at ours with instruments of similar capability wouldn't detect Earth because it's too small, and might miss Jupiter because it's orbit is too wide and slow.
This particular planet was detected by a different method; it happens that the planet's orbit causes it to transit between the star and Earth, blocking a small part of the star's light. If the planet is big enough, this drop in the star's intensity is detectable. But such an orbital alignment must be something like a one in a million shot...
"the Drake equation gives us NO new information about the statistics of life"
This is true, but it's not the point of the Drake equation. Frank Drake came up with it back before he founded SETI, as a way to speculate quantitatively about the possibility of life elsewhere. It's utility is that it separates the unknown factors regarding life in our Galaxy, so that the mind can deal with each independently. I mean, think about it:
Conversation about life in the universe, pre-Drake equation:
"How many civilizations do you think there are in our Galaxy?"
"I have no idea."
"Heavy."
"Yeah."
Same conversation, armed with DE:
"How many civilizations do you think there are in our Galaxy?"
"Who knows? But there are billions of stars, and I think about half probably have a planetary system of some kind."
"Yeah, but how many of those could support life? Even in our system, apparently only 1 of 9."
"OK, so let's go with that, for now. But how many of the life-bearing planets would evolve intelligent life?...."
and so on. The Drake Equation provides a framework for speculation about The Big Question: Is there intelligent life elsewhere in the universe?. It was whimsically conceived, and it was not meant to provide new information about the question.
Liberal (adj.): Free from bigotry; open to progress; tolerant of others.