Planet at 15000 ly

[Lord Zentei]

Part news, part science. Move if you feel like it.

The significance is the distance of the new planet, and the method by which it was discovered.

Lens method finds far-off world

By Dr David Whitehouse
Science editor, BBC News website

An international team of astronomers has found a planet which, at about 15,000 light-years from Earth, is one of the most distant yet detected.

The new world was discovered when its parent star's gravity distorted the light from an even more distant star.

The way the distant star's light changed betrayed the planet's presence.

Two amateur astronomers in New Zealand helped find the world using "backyard" telescopes, showing that almost anyone can become a planet hunter.

The newly discovered world is several times the mass of Jupiter, but astronomers say the microlensing technique used to find the planet worked so well that it could be used to find much smaller, Earth-sized planets.

Pattern in the signal

Microlensing occurs when a massive object in space, like a star, crosses in front of another star shining in the background.

The near object's gravity bends the light rays from the more distant object and magnifies them like a lens. Here on Earth, we see the star get brighter as the lens crosses in front, and then fade as the lens moves away.

On 17 March 2005, Andrzej Udalski, professor of astronomy at Warsaw University, Poland, and leader of the Optical Gravitational Lensing Experiment (Ogle), noticed that just such an event was about to occur near the centre of our galaxy.

A month later, when the more distant star had brightened a hundred-fold, astronomers from Ogle and from the Microlensing Follow Up Network (MicroFun) detected a new pattern in the signal - a rapid distortion of the brightening - which could only be explained by an additional object close to the foreground star - a planet.

"There's absolutely no doubt that the star in front has a planet, which caused the deviation we saw," said Andrew Gould, of Ohio State University, US.

Gould's estimate of a 15,000-light-year distance to the new planet is an approximation, and he says he will need more data to refine the number. A light-year is the distance light travels in a year - about 9.5 trillion km (six trillion miles). (A trillion here is taken to be a million, million).

Global network

Because the scientists were able to monitor the light signal with high precision, Gould thinks the technique could easily have revealed an even smaller planet.

"If an Earth-mass planet was in the same position, we would have been able to detect it," he said.

Ogle finds more than 600 microlensing events each year using a dedicated 1.3m telescope at Las Campanas Observatory in Chile. MicroFun is a collaboration of astronomers from the US, Korea, New Zealand, and Israel that picks out those events that are most likely to reveal planets and monitors them from telescopes around the world.

"That allows us to watch these events 24/7," Gould said. "When the Sun rises at one location, we continue to monitor from the next."

Two of these telescopes belong to two avid New Zealand amateur astronomers who were recruited by the MicroFun team. Grant Christie of Auckland used a 14-inch (35cm) telescope, and Jennie McCormick of Pakuranga used a 10-inch (25cm) telescope.

Both share co-authorship on the paper submitted to Astrophysical Journal Letters.

[Guy N. Cognito]

And to think I was explaining how cool light was because it bends around objects to my wife just last night. Talk about a good idea, I guess this means we'll be discovering more planets that we won't be going to any time soon.

[wolveraptor]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

[Zero]

It isn't any kind of guarantee of anything, but we're really wanting to find earth-like planets, and the first step is finding earth like ones to figure crap out. I guess we really want to know how rare life may or may not be in the universe.

[Patrick Degan]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

Because they are the most likely candidates as life-bearing worlds. Planets smaller than that won't have sufficent gravity to retain a terrestrial atmosphere, and ones larger than that are most likely to be gas-giants.

[Drunk Monkey]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

Because if a meteor comes rocketing toward Earth we will have a place to run to.

[Stark]

Because if a meteor comes rocketing toward Earth we will have a place to run to.

So effortlessly amusing... Official SDN Jester, says I.

[Drunk Monkey]

Because if a meteor comes rocketing toward Earth we will have a place to run to.

So effortlessly amusing... Official SDN Jester, says I.

It happens when you’re a primate who happens to be hammered.

[Drooling Iguana]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

Because if a meteor comes rocketing toward Earth we will have a place to run to.

We've already got Mars for that. Extrasolar planets are so that we'll have a place to run to when the sun burns out.

[SyntaxVorlon]

SQUEEEE!

[nickolay1]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

Because if a meteor comes rocketing toward Earth we will have a place to run to.

We've already got Mars for that. Extrasolar planets are so that we'll have a place to run to when the sun burns out.

By the time the sun burns out, we'll most certainly be technologically advanced enough to construct a ship large enough to house the entire human race, unless, of course, the population maintains its current exponential growth. In any case, it's extremely unlikely that we'll be colonizing any extrasolar earth-like planets. They're extremely rare (judging by current detection methods), and even fewer are are likely to harbor an atmosphere hospitable to humans. And let's not forget the problem of travelling there...

[Drunk Monkey]

Because if a meteor comes rocketing toward Earth we will have a place to run to.

We've already got Mars for that. Extrasolar planets are so that we'll have a place to run to when the sun burns out.

By the time the sun burns out, we'll most certainly be technologically advanced enough to construct a ship large enough to house the entire human race, unless, of course, the population maintains its current exponential growth. In any case, it's extremely unlikely that we'll be colonizing any extrasolar earth-like planets. They're extremely rare (judging by current detection methods), and even fewer are are likely to harbor an atmosphere hospitable to humans. And let's not forget the problem of travelling there...

Ever heard of terforming.

[nickolay1]

Yes, but obviously not all planets can be terraformed. For instance, Mars has plenty of carbon dioxide, which theoretically allows for the use of modified terrestrial plants/other organisms. However, if you come across another planet, with an atmosphere of, say, entirely nitrogen, your job just became far more difficult. One can speculate though, that by the time we are advanced enough to travel such distances, terraforming will be an insignificantly easy task. In that case, why not just use the advanced technology to find hospitable planets and use those instead?

[Ravengrim]

I am not a biologist or anything, but couldnt life exist on a gas giant or something? Granted, it would be completely different and, well, alien, but isnt that what we are ultimately looking for? Maybe we are the only humanoids in the galaxy. Maybe every other sentient beings thought processes are so different that meaningful communication is impossible. I think that they should at least look for life on these extra-solar planets even if they dont fit the current life-sustaining definition. Of course, an earth-like planet or two would solve a lot of our problems here.

[Zero]

nickolay, your speculation that we'll be advanced enough by the time the sun goes out isn't probably correct. I mean, we won't specifically develope terraforming processes, until we have the ability to get to other planets anyways, and we probably won't even start developing this until we see that overpopulation is REALLY fucking us up, or if we realize that the sun's going to go red giant soon. Humans have a tendency of seeing the smaller picture, and only starting to actually act when it seems profitable or necessary to do so. This isn't the case with star travel, and won't be until we need to leave. Terraforming won't be able to be put into practice until we actually can get to earthlike planets, so we may not develope this at all for a long LONG time...

[nickolay1]

It's quite likely, in my opionion, that we'll be advanced enough by then. After all, we still have a few billion years until the sun burns out.

[speaker-to-trolls]

By the time the sun burns out, we'll most certainly be technologically advanced enough to construct a ship large enough to house the entire human race, unless, of course, the population maintains its current exponential growth. In any case, it's extremely unlikely that we'll be colonizing any extrasolar earth-like planets. They're extremely rare (judging by current detection methods), and even fewer are are likely to harbor an atmosphere hospitable to humans. And let's not forget the problem of travelling there...

You can't really judge by current detection methods, seeing as how they're only good enough to detect things at least as big as Jupiter.
Also, the idea that small planets can't hold down an atmosphere is a bit of an oversimplificatication, note that Venus, approximately the same size as Earth, has an atmosphere hundreds of times thicker, and Titan, which is much smaller, has an atmosphere just as thick.

[nickolay1]

Actually, there have been a few extrasolar planets of a mass close to that of the Earth detected. While it is true that current detection methods aren't very sensitive, it can be fairly safely assumed that such planets are rare.
Regarding the atmospheres of extrasolar planets, I was not referring to the size. Instead, I was referring to the compositions of the atmospheres themselves.

[wolveraptor]

What's with the obsession with finding Earth-size planets? How is that any guarantee of life?

Because they are the most likely candidates as life-bearing worlds. Planets smaller than that won't have sufficent gravity to retain a terrestrial atmosphere, and ones larger than that are most likely to be gas-giants.

Bah. I spit on your conceptions of what life can and cannot be. Why does life need to exist within a terrestrial atmosphere? Why can't it evolve in thinner or thicker atmospheres? Of course, it is impossible to prove a negative, but the only way to prove that life could evolve in non-terrestrial environments would be to find alien life, and we aren't even remotely close to doing that.

[Lord Zentei]

Bah. I spit on your conceptions of what life can and cannot be. Why does life need to exist within a terrestrial atmosphere? Why can't it evolve in thinner or thicker atmospheres? Of course, it is impossible to prove a negative, but the only way to prove that life could evolve in non-terrestrial environments would be to find alien life, and we aren't even remotely close to doing that.

Based on what we know, it is the logical place to start looking since we are most familiar with that type of life.

No one is claiming that life cannot exist elsewhere: aren't we looking for life on Mars and planning a search on Europa? Incedentally, amino acid molecules have been found in comets and sugars have been found in nebulae.

[Drunk Monkey]

Yes, but obviously not all planets can be terraformed. For instance, Mars has plenty of carbon dioxide, which theoretically allows for the use of modified terrestrial plants/other organisms. However, if you come across another planet, with an atmosphere of, say, entirely nitrogen, your job just became far more difficult. One can speculate though, that by the time we are advanced enough to travel such distances, terraforming will be an insignificantly easy task. In that case, why not just use the advanced technology to find hospitable planets and use those instead?

Because if the human race keeps propagating the way it does were going to need a shit load of planets, and the fact that there are so few hospitable planets out there terraforming is just a must.

[Darth Yoshi]

All this assuming that humanity doesn't blow itself to kingdom come first.

[Drunk Monkey]

All this assuming that humanity doesn't blow itself to kingdom come first.

Humanity can cut it’s guts out for all I care. I will be in a bomb shelter in the boonies’s wile that happens with shotgun in one hand, bigger gun in the other.

[Edi]

I am not a biologist or anything, but couldnt life exist on a gas giant or something? Granted, it would be completely different and, well, alien, but isnt that what we are ultimately looking for? Maybe we are the only humanoids in the galaxy. Maybe every other sentient beings thought processes are so different that meaningful communication is impossible. I think that they should at least look for life on these extra-solar planets even if they dont fit the current life-sustaining definition. Of course, an earth-like planet or two would solve a lot of our problems here.

I don't see why gas giants couldn't have life forms. They'd have to be microscopic, probably single celled and they would be restricted to a certain pressure range inside the atmosphere, but like you said, that does not have much bearing on us.

As for sentience etc, there are sentient creatures on earth with us, e.g. dolphins, whales, chimps, orangutangs, gorillas, some parrots and others. It just so happens that most of them we have a very difficult time communicating with, in some cases practically impossible. Some of it is due to alien thought processes, some to means of communication, and some to the actual level of sentience being too low to be able to comprehend anything abstract. So we are not the only sentients around, we are just the most advanced in many respects on our own turf.

As for other sentient life forms in the universe, the odds are that they exist, even simultaneously with us, but the odds of them being found in our own galaxy are so minuscule I wouldn't want to bet on that. Given the timeframes involved in evolutionary processes, the rise of sentience and extinction cycles caused by different types of natural events compared to the time frames of the overall existence of life, the window of opportunity for simultaneous existence of sentient life forms in our galaxy is so small as to be non-existent. The odds of actually finding them and making contact are another order of magnitude or ten smaller and are predicated on them having technology similar to ours.

Edi

[Patrick Degan]

Yes, but obviously not all planets can be terraformed. For instance, Mars has plenty of carbon dioxide, which theoretically allows for the use of modified terrestrial plants/other organisms. However, if you come across another planet, with an atmosphere of, say, entirely nitrogen, your job just became far more difficult. One can speculate though, that by the time we are advanced enough to travel such distances, terraforming will be an insignificantly easy task. In that case, why not just use the advanced technology to find hospitable planets and use those instead?

Because if the human race keeps propagating the way it does were going to need a shit load of planets, and the fact that there are so few hospitable planets out there terraforming is just a must.

Or you can build large artificial orbital habitats with spin-gravity and within range of the star to most efficently harvest its energy output. A project which would provide habitable space for a large spacefaring population far quicker than terraforming would.