NASA discovers 715 new planets

[wautd]

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(CNN) -- Our galactic neighborhood just got a lot bigger. NASA on Wednesday announced the discovery of 715 new planets, by far the biggest batch of planets ever unveiled at once.

By way of comparison, about 1,000 planets total had been identified in our galaxy before Wednesday.

Four of those planets are in what NASA calls the "habitable zone," meaning they have the makeup to potentially support life.

The planets, which orbit 305 different stars, were discovered by the Kepler space telescope and were verified using a new technique that scientists expect to make new planetary discoveries more frequent and more detailed.



Is this the ultimate space suit for Mars?

Spotted: Mystery rock on Mars "We've been able to open the bottleneck to access the mother lode and deliver to you more than 20 times as many planets as has ever been found and announced at once," said Jack Lissauer, a planetary scientist at NASA's Ames Research Center in California.

Launched in March 2009, the Kepler space observatory was the first NASA mission to find planets similar to Earth that are in, or near, habitable zones -- defined as planets that are the right distance from a star for a moderate temperature that might sustain liquid water.

Tuesday's planets all were verified using data from the first two years of Kepler's voyage, meaning there may be many more to come.

"Kepler has really been a game-changer for our understanding of the incredible diversity of planets and planetary systems in our galaxy," said Douglas Hudgins, a scientist with NASA's astrophysics division.

The new technique is called "verification by multiplicity," and relies in part on the logic of probability. Instead of searching blindly, the team focused on stars that the technique suggests are likely to have more than one planet in their orbit.

NASA says 95% of the planets discovered by Kepler are smaller than Neptune, which is four times as big as Earth.

One of them is about twice the size of Earth and orbits a star half the size of Earth's sun in a 30-day cycle.

The other three planets in habitable zones also are all roughly twice the size of Earth. Scientists said the multiplicity technique is biased toward first discovering planets close to their star and that, when further data comes in, they expect to find a higher percentage of new planets that could potentially have a life-supporting climate like Earth's.

"The more we explore the more we find familiar traces of ourselves amongst the stars that remind us of home," said Jason Rowe, a research scientist at the SETI Institute in Mountain View, California, and co-leader of the research team.

Wow, I still remember when finding one planet was a big deal

[Borgholio]

It's a really good thing that Kepler discovered so many planets before it broke down. I'm eagerly awaiting the next planet-finding mission, whatever it is.

[Eternal_Freedom]

Hell, I remember the first Kepler announcement. It was two days after we had a Planetary Geology lecture on the formation of solar systems. Then in the next lecture the professor said "Right, forget everything I said last week because Kepler just proved us wrong. Here's how it works this week."

[Borgholio]

Yeah when the first results were coming in so quickly, I thought to myself, "Well...the universe just got much MUCH bigger..."

[Channel72]

The stats are pretty interesting. So, approx 4 / 1000 (0.004%) are potentially habitable, giving us ~1 billion potentially habitable planets in our galaxy.

Viable solutions to the Fermi paradox are starting to get more ominous. Or maybe large brains are just a total fluke.

[Borgholio]

Potential solutions to the Fermi paradox are starting to get more ominous.

I would find it mildly amusing if the idea that we're a deliberately isolated "nature preserve" turned out to be true.

[Broomstick]

Please expand on that statement. I've heard of the Fermi paradox, but I'm not certain how this finding makes things more ominous.

Even if there are 1 billion habitable planets in the galaxy (habitable by "life as we know it") it is unlikely that all of them will actually have life, many of those that do may well be stuck at the "pond scum" level (as Earth itself was for billions of years), a certain percentage will have been subjected to extinction events, while some subset may evolve complex life with the potential for intelligence we have no idea how likely intelligence leading to our sort of civilization may be...

I always throught there were too many unknowns to make the Fermi "paradox" or estimates of life on other worlds anything more that wild ass guesses.

The main difference is that now we are getting some idea of how common planets are around other solar systems, and how often they land in what we consider the habitable zone (for all we know for sure, there may be several types of habitable zone). That's it. We have no idea if life exists at all on those planets. Until we do, we can't even begin to estimate how common life is in the universe, and that would still be a long way from "solving" the Fermi "paradox".

It may be that our sort of civilization is, in fact, rare anywhere. Any that exist may be too far away to make meaningful contact with them. I would like it to be otherwise, I hope it is otherwise, but reality is a bitch sometimes.

[Borgholio]

The Fermi paradox also horribly underestimated the number of planets out there, as well as the ability of those planets to support life. If each solar system has, say, a half-dozen planets, then that's easily 600 billion + planets out there...not counting god knows how many habitable moons orbiting Gas Giants and such. Civilization could just be fairly rare, while primitive life is everywhere.

[Broomstick]

Well, hell, bronze age civilization could even be fairly common but our level of tech rare. There could be a billion bronze-age civilizations, or even iron age, but if they don't progress past where we were around 1850 they won't be sending out any signals we could pick up, and they won't detect ours.

[Borgholio]

That is actually another quite valid, if somewhat depressing answer to the paradox. What if *we* are the most advanced civilization in the galaxy?

[dragon]

Well, hell, bronze age civilization could even be fairly common but our level of tech rare. There could be a billion bronze-age civilizations, or even iron age, but if they don't progress past where we were around 1850 they won't be sending out any signals we could pick up, and they won't detect ours.

There could be a thousand civ our level scattered throughout the galaxy and their radios just has reached us as they as spread out so far. Hell could we detect radios from a planetary source at a few thousand lt years with stars between us and them

[Borgholio]

Hell could we detect radios from a planetary source at a few thousand lt years with stars between us and them

Depends on the strength of their transmissions. If we are trying to listen to their common radio and TV broadcasts...no way. Those are far too faint. If they deliberately beam a signal to our part of the galaxy using something the size of Arecibo, then yes we actually could detect that fairly strongly.

[StarSword]

Something xkcd's Randall Munroe wrote that might be relevant:

The full picture is more complicated, but the bottom line is that as our technology has advanced, less of our radio traffic has been leaking out into space. We’re closing down the giant transmitting antennas and switching to cable and fiber and tightly-focused cell-tower networks.[2]

While our TV signals may have been detectable—with great effort—for a while,[3] that window is closing. In the late 20th century, when we were using TV and radio to scream into the void at the top of our lungs, the signal probably faded to undetectability after a few light-years.[4] The potentially habitable exoplanets we’ve spotted so far are dozens of light-years away, so the odds are they aren’t currently repeating our catchphrases.

But TV and radio transmissions still weren’t Earth’s most powerful radio signal. They were outshone by the beams from early-warning radar.[4]

Early-warning radar, a product of the Cold War, consisted of a bunch of ground and airborne stations scattered around the Arctic. These stations swept the atmosphere with powerful radar beams 24/7, often bouncing them off the ionosphere, and people obsessively monitored the echos for any hints of enemy movement. (I wasn’t alive during most of this period, but from what I hear, the mood was a little tense.)

These radar transmissions leaked into space, and could probably be picked up by nearby exoplanets[5] if they happened to be listening when the beam swept over their part of the sky. But the same march of technological progress that made the TV broadcast towers obsolete has had the same effect on early-warning radar. Today’s systems—where they exist at all—are much quieter, and may eventually be replaced completely by new technology.

[Channel72]

That's a compelling analysis. But I think that most of the malaise associated with the Fermi paradox has more to do with why we haven't observed them, rather than why they haven't observed us. Presumably, enough time has passed that potential alien civilizations should have been able to develop highly visible super-structures like dyson swarms or Von Neumann probes, yet we've never observed anything in the observable Universe that can't be attributed to natural, physical phenomena.

There probably is intelligent life out there, but it's not necessarily common enough that it occurs more than once or twice in each galaxy. It may simply be that biological neural nets capable of generating homo-sapien level intelligence are exceedingly uncommon in this universe.

[Channel72]

It may be that our sort of civilization is, in fact, rare anywhere. Any that exist may be too far away to make meaningful contact with them. I would like it to be otherwise, I hope it is otherwise, but reality is a bitch sometimes.

Please. The fact that Earth-like planets are so fucking common is news more exciting than anything I expected to come out in my lifetime. It's really amazing times we live in.

And even if we are the only ones in this galaxy... so what? We'll conquer it ourselves if we have to.

[Broomstick]

You mean if we are able to.

There may not be any Dyson spheres or von neuman probes or mega-structures because it may not be possible to build them, or practical to build them. We may not ever be able to leave our solar system, and maybe nobody else can, either.

I'd like for things to be otherwise but it's not up to me, it's up to physics.

[Eternal_Freedom]

It may be that our sort of civilization is, in fact, rare anywhere. Any that exist may be too far away to make meaningful contact with them. I would like it to be otherwise, I hope it is otherwise, but reality is a bitch sometimes.

Please. The fact that Earth-like planets are so fucking common is news more exciting than anything I expected to come out in my lifetime. It's really amazing times we live in.

And even if we are the only ones in this galaxy... so what? We'll conquer it ourselves if we have to.

Where, pray tell, did you get the idea that Earth-type planets are "so fucking common?" We've found a bunch in the habitable zone, but that alone does not make a planet Earth-like. All it means is that the power per square metre of solar radiation is enough to have liquid water on the surface. Important? Very much so. All that matters? Absolutely not.

That doesn't actually mean there is water there. If the planet is a Mercury-type rock ball it doesn't matter. If it's a Venus-type world then its uninhabitable anyway. Hell, if it's a gas giant (I'm pretty sure we've found at least one int he habitable zone) then there isn't even a surface to stand on.

[Channel72]

You mean if we are able to.

There may not be any Dyson spheres or von neuman probes or mega-structures because it may not be possible to build them, or practical to build them. We may not ever be able to leave our solar system, and maybe nobody else can, either.

I'd like for things to be otherwise but it's not up to me, it's up to physics.

OR..., there may not be observable mega-structures because homo sapien level intelligence is exceedingly rare. There's nothing physically impossible about constructing dyson swarms or other Kardeshev-2 level mega structures. We just haven't observed them. Taking into consideration the fact that in, let's see... less than 5,000 years (a veritable blip on cosmic timescales), we've gone from Bronze age tribes to landing robots on Mars, I'm more inclined to believe that human-level intelligence is simply a very rare phenomenon, rather than believe it's physically impossible to leave the solar system. Obviously, it isn't.

[Tony Stark]

Yeah remember that both Mars and Venus are theoretically in the habitable zone.

[Broomstick]

There's nothing physically impossible about constructing dyson swarms or other Kardeshev-2 level mega structures.

There's nothing physically impossible about converting one element into another - in fact we've done that! - but the energy costs are prohibitive, which is why we measure such conversions in atoms rather than tons.

Sure, there's nothing impossible about such structures but getting the energy to actually construct them, nevermind any other obstacles we might encounter, like particular materials that might be hard to obtain in sufficient quantity, may make them so impractical civilizations don't ever manage to actually make them.

[Guardsman Bass]

The planets they found in the habitable zones might be habitable, but their size is a problem - even the smallest one is 1.8 times the radius of Earth. They could be water balls or planets with a significant hydrogen-helium atmosphere depending on how massive they are. This Arxiv paper attempted to model potential exo-planet atmospheres, and planets with a radius beyond 1.75 times that of Earth tended more towards being a "sub-Neptune" that a rocky planet due to their expected mass.

As for the Fermi's Paradox issue, the easiest explanation (besides "there are too many unknowns to do more than speculate") is great separation in space and time. If civilizations are fairly rare and highly separated, then the odds could be such that you don't get "break-out" species spreading all over the galaxy - especially if interstellar voyages require a considerable expenditure of resources and technology. If they pop up with great intervals of time, then we might simply have not been around when they passed through the neighborhood - an alien spacecraft passing through the solar system in 24 million BCE wouldn't have found any interesting signs of intelligence.

Yeah remember that both Mars and Venus are theoretically in the habitable zone.

Venus isn't, although it might have been for a brief period of time early in the solar system's history when the Sun was much fainter. Mars is possibly at the outer edge of the habitable zone at present, although it wouldn't have been 4 billion years ago, and in any case it was too small.

Sure, there's nothing impossible about such structures but getting the energy to actually construct them, nevermind any other obstacles we might encounter, like particular materials that might be hard to obtain in sufficient quantity, may make them so impractical civilizations don't ever manage to actually make them.

That's where it comes back to the number of spacefaring civilizations out there. The more there are, the more you're likely to get at least one that ends up trying interstellar exploration or massive space engineering for whatever bizarre alien cultural reasons. But if there aren't that many, then you could end up with no break-out species (at least in this galaxy).

Depends on the strength of their transmissions. If we are trying to listen to their common radio and TV broadcasts...no way. Those are far too faint. If they deliberately beam a signal to our part of the galaxy using something the size of Arecibo, then yes we actually could detect that fairly strongly.

Here's an FAQ I found on it, although I can't vouch for its reliability. Using an Arecibo-sized radio telescope, most of the signals we blasted out in all directions (such as broadcast TV signals) wouldn't be detectable at even a single light-year (the longest range was 0.3 LY). The narrow-band stuff was detectable much farther out, but it's also much less likely for them to pick up.

[Sky Captain]

There's nothing physically impossible about constructing dyson swarms or other Kardeshev-2 level mega structures. We just haven't observed them.

How visible they would be anyway? What percentage of solar output Dyson swarm would have to collect for our astronomers to say hmm there is something weird going on in that star system?

[Darmalus]

There's nothing physically impossible about constructing dyson swarms or other Kardeshev-2 level mega structures. We just haven't observed them.

How visible they would be anyway? What percentage of solar output Dyson swarm would have to collect for our astronomers to say hmm there is something weird going on in that star system?

From what I understand it would be a star with no visible light except in the infrared (heat) spectrum. No natural star would look like that.

[Sky Captain]

There's nothing physically impossible about constructing dyson swarms or other Kardeshev-2 level mega structures. We just haven't observed them.

How visible they would be anyway? What percentage of solar output Dyson swarm would have to collect for our astronomers to say hmm there is something weird going on in that star system?

From what I understand it would be a star with no visible light except in the infrared (heat) spectrum. No natural star would look like that.

That would be in case of full hard shell Dyson sphere which is not realistic. A realistic Dyson swarm would consist of multiple solar power sattellites orbiting close to a star intercepting some fraction of stellar output. Question then is how extensive that swarm should be for astronomers to notice something weird is happening.

[Borgholio]

Venus isn't, although it might have been for a brief period of time early in the solar system's history when the Sun was much fainter. Mars is possibly at the outer edge of the habitable zone at present, although it wouldn't have been 4 billion years ago, and in any case it was too small.

Well not exactly. Venus and Mars are both within the habitable zone...it's just their atmospheres that screw things over. Without the huge blanket of smog, Venus would be warm...but still within the realm of liquid water. Mars actually gets to a comfortable 70 degrees F in the summer at the equator...it's just the thin air that causes it to get cold as fuck at night. I mean right now if you walked on Mars in the summer, you could do so in sandals and shorts...so long as you had a breather.

Using an Arecibo-sized radio telescope, most of the signals we blasted out in all directions (such as broadcast TV signals) wouldn't be detectable at even a single light-year (the longest range was 0.3 LY). The narrow-band stuff was detectable much farther out, but it's also much less likely for them to pick up.

Right, that's exactly what I said. Even using the biggest telescope arrays on Earth, we would not be able to pick up our own TV transmissions more than 100 - 200 LY away. But if one Arecibo was beaming a signal to another Arecibo at full power, they would be able to communicate (relatively) easily even across the galaxy.