Scientists Predict That One in Every Five Stars Has a "Habitable" Planet

[Steven Bogos]

Scientists Predict That One in Every Five Stars Has a "Habitable" Planet

Out of the 100 billion stars in our galaxy, 20 billion have planets that could potentially sustain life.

Aliens. They may be more likely than you think. We all sort of hoped that they might be "out there" somewhere in the galaxy, and now NASA astronomers have estimated that as many as 20 billion of the 100 billion stars in our galaxy have planets that could potentially sustain life.

Using data from NASA's Kepler space telescope they argue that one in five stars like the Sun hosts an Earth-sized world located in the "habitable zone". The "habitable zone" describes the region around a star where temperatures allow for water to stay liquid at the surface, and we all know that water is the key building block of life.

"What this means is, when you look up at the thousands of stars in the night sky, the nearest Sun-like star with an Earth-size planet in its habitable zone is probably only 12 light years away and can be seen with the naked eye," said the co-author of the study, Erik Petigura, from the University of California, Berkeley.

While this is some pretty amazing news, other team members cautioned that just because planets exist in the habitable zone, does not mean that they are automatically hospitable to life. "Some may have thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive," said another author, Geoff Marcy.

Researchers came to this conclusion by first gathering data by combing through some 42,000 stars to find habitable planets, and then extrapolating the data to apply to the entire Milky Way galaxy.

Source: BBC [http://www.bbc.co.uk/news/science-environment-24824007]

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[Alleged_Alec]

Meh. You need more for a planet to be habitable than just being in the Goldilocks zone. Furthermore: we're not even sure that it needs to be in there. There are plenty of non-water liquids which could be used by alien species.

 

[Alleged_Alec]

Meh. You need more for a planet to be habitable than just being in the Goldilocks zone. Furthermore: we're not even sure that it needs to be in there. There are plenty of non-water liquids which could be used by alien species.

seriously? this is amazing news. it wasnt that long ago that they didnt even know if extrasolar planets even existed and its suddenly become meh

As far as I know, this is pretty old news. I remember having discussions about this 6 years ago during physics classes.

 

[The_Darkness]

Um... I think that title should be "NASA predicts that..." - the BBC are just doing the reporting on it.

Anyway, I'm not that surprised, but I am aware that everything that makes alien life more likely also makes the Paradox [http://en.wikipedia.org/wiki/Fermi_paradox] more of a problem...

 

[Saulkar]

Meh. You need more for a planet to be habitable than just being in the Goldilocks zone. Furthermore: we're not even sure that it needs to be in there. There are plenty of non-water liquids which could be used by alien species.

One thing you have to consider is the reason that carbon based molecules are considered the premiere building block of life is because of of its ability to form complex organic bonds that can break just a easily without being fragile. These bonds however are particularly finicky as to what environment they can function in and thus that is why we search for planets in the Goldilocks zone as carbon based life (by far and large the most likely to exist) can only exist in this region. Alternatively there is Silicon. However silicon produces fewer complex bonds as carbon required for anything resembling metabolic life. On the other hand, life produced from it could form in much more extreme environments, possibly even devoid of any liquid sustenance.

https://en.wikipedia.org/wiki/Silicon_biochemistry#Silicon_biochemistry

However said bonds are incredibly powerful, not all that complex, and do not break easily or all that fast. Life formed from silicon would likely be incredibly slow (unless existing at far greater temperatures and pressure), or limited to some sort of crystalline plant-life. Most of my information came from narrations from Stephen Hawking and Dr. Michio Kaku on various films that I cannot find online unfortunately. I would love to link you to them but alas, I cannot.

P.S. I noticed you mentioned physics class. What do you know that I do not or can correct?

 

[Petromir]

Um... I think that title should be "NASA predicts that..." - the BBC are just doing the reporting on it.

Anyway, I'm not that surprised, but I am aware that everything that makes alien life more likely also makes the Paradox [http://en.wikipedia.org/wiki/Fermi_paradox] more of a problem...

Not really NASA either, the data was collected by NASAs teliscope, but it looks like it was then some univeristy academics that wrote this paper.

NASA of course deserves some credit, without their kit it wouldnt be possible, but the prediction as such looks to come from outside people. Not uncommon when expensive kit is needed this, allowing others to book time with it or to use data from it.

 

[Smooth Operator]

Well people should understand that this is a very wide estimate, yes many solar systems have a Goldilocks zone but that doesn't mean there is a planet in it, or that the planet is stable, or that it has the right elements in it's composition, or that the sun is stable and limited in it's deadly radiation,... and many more factors that you can only observe from up close, which we aren't so at best you can call this eyeballing it.

But it does offer great prospects in expansion proceedings for the Imperium of Man.

 

[CardinalPiggles]

This information would certainly narrow down the search for habitable planets, but how about we actually work on being able to GET to one first, hm?

 

[6urk17s]

There are plenty of non-water liquids which could be used by alien species.

Those planets are only useful as bombing practice anyway.

 

[omega 616]

Without getting too hippy, man. Why does life need water to survive? Is it totally beyond the realm of possibility that life could be totally different somewhere else? When I'm watching star trek (or other similar shows) it always strikes me as odd that 90% of aliens are identical to humans... They all are bipedal, legs, arms, head, shoulders etc they just have other stuff, like ridges and big ears. (I know it was probably down to budget or time or something)

Taking that same idea, why do aliens need to follow our predefined rules for life?

I'm probably speaking from a very ignorant point of view but I like to keep a very open mind about other forms of life. I mean there are teeny tiny hippo looking creatures on this planet that have been subjected to all kinds of tests and lived, they just hibernate till the abuse stops.

I think it would be kind of cool if there was another... Dimension (for lack of a better word) to this planet and there was another species/form of life living on the same planet as us but neither species/form of life knew about the other. Like I said, I like to keep an open mind, science is cool and all (my favourite subject in school) but it doesn't have every answer yet.

 

[GundamSentinel]

The number of habitable planets might actually be quite a bit higher than the 20 billion that were predicted, because this research does not include red dwarf stars than can very easily host habitable planets as well. Previous estimates say that even 15-50% of these red dwarfs may have such planets (even higher than the 14-30% of Sun-like stars).

Only one problem: they haven't yet found definitive evidence of a single one, what with that damn Kepler breaking down. :S

And naturally, some assumptions were made here. There is no proof that these planets would even be terrestrial rocky planets but maybe balls of gas. And as said, a planet being rocky and in the right place doesn't automatically make it suitable for life. Plus, these calculations were based on a finite set of samples and some rough extrapolation.

But still, great news!

 

[Psychobabble]

In other words "Scientists more than happy to make earthshaking predictions they know they'll never have to back up with actual proof."

 

[nuba km]

Um... I think that title should be "NASA predicts that..." - the BBC are just doing the reporting on it.

Anyway, I'm not that surprised, but I am aware that everything that makes alien life more likely also makes the Paradox [http://en.wikipedia.org/wiki/Fermi_paradox] more of a problem...

My problem with the fermi paradox is that it does not take into account the possibility of things like civil wars occurring between residence of the new planet and the old (like there was between america and england) or stuff such as maybe advance civilisations don't want to contact new civilisations until they are ready. Heck maybe humans are muscle bound toxic beasts compared to other alien species and they haven't contact us as they are scared of us and their laws prohibit them from wiping us out. Also the aliens cultures could be incredibly different and something about it means they avoid us. In short I don't agree with the fermi paradox.

OT: so 1 in 5 could have a plant that has 1 condition to be inhabitable by carbon based lifeforms.

 

[MrFalconfly]

Without getting too hippy, man. Why does life need water to survive? Is it totally beyond the realm of possibility that life could be totally different somewhere else? When I'm watching star trek (or other similar shows) it always strikes me as odd that 90% of aliens are identical to humans... They all are bipedal, legs, arms, head, shoulders etc they just have other stuff, like ridges and big ears. (I know it was probably down to budget or time or something)

Taking that same idea, why do aliens need to follow our predefined rules for life?

I'm probably speaking from a very ignorant point of view but I like to keep a very open mind about other forms of life. I mean there are teeny tiny hippo looking creatures on this planet that have been subjected to all kinds of tests and lived, they just hibernate till the abuse stops.

I think it would be kind of cool if there was another... Dimension (for lack of a better word) to this planet and there was another species/form of life living on the same planet as us but neither species/form of life knew about the other. Like I said, I like to keep an open mind, science is cool and all (my favourite subject in school) but it doesn't have every answer yet.

Without getting too nerdy, it's basically because water is one of the best solvents and it consists of the most common elements in the universe (Hydrogen and Oxygen, molecular water and water-ice aren't that uncommon in the universe).

If you brake up the human body into it's constituent elements it basically has the same spectral profile as the universe. The most common element in your body is hydrogen (63%), followed by Oxygen (24%), and then Carbon (12%).

Turns out the biblical "dust-to-dust" concept needs to be "universe-to-universe", since we've more in common with the universe at large than our own little Earth.

 

[Flatfrog]

Without getting too hippy, man. Why does life need water to survive? Is it totally beyond the realm of possibility that life could be totally different somewhere else? When I'm watching star trek (or other similar shows) it always strikes me as odd that 90% of aliens are identical to humans... They all are bipedal, legs, arms, head, shoulders etc they just have other stuff, like ridges and big ears. (I know it was probably down to budget or time or something)

Obviously yes, it was all down to budget - simplest way to make an alien is to take a person and add a bit of prosthetic. However, it's not unreasonable to assume that life will follow certain standard evolutionary pathways.

Cells/Tissues/Organs/Systems: There's a good chance that most life will be cellular-based in some form. The easiest way to build anything is from small pieces of distinct types. Like life on this planet it could well be organised into tissues and organs.

DNA: Obviously it's unlikely that any other life will use DNA, but they're likely to store their genetic information somehow. It could be in a long polymer like DNA, or it could be on a surface or some other form. But in any case, life requires replication so it'll need some kind of replicating chemical data structure.

Eyes: These will almost certainly exist everywhere. They appear to have evolved several times on Earth, they're easy to make and they're an obviously useful sense organ. Any mobile life form needs to have some sense of its surroundings and light is everywhere. What's more, they'll probably use frequencies similar to ours because those are the frequencies most easily detectable by cells. Once you have eyes, there's a good chance you'll also get some use of visual signals for communication.

Ears: Like eyes, these seem pretty much guaranteed. Sound waves are a useful source of information. Once you have ears, there's a good chance you'll also get some use of sound for communication.

Smell/taste: These are pretty much the same thing - a sense based on identifying individual molecules in the near vicinity. Seems a good chance most life will have something like it, but it's likely to be very different from ours. Once you have smell, there's a good chance you'll also get some use of chemical signals for communication.

Brain: It seems likely that any life will evolve some kind of central nervous system but whether it would necessarily have a single organ that controls it seems up for grabs.

Ecology: All life will have to take in energy and use it to move, grow and reproduce. That means we'd be likely to see similar patterns emerging everywhere - producers that take in readily available energy in the form of light, heat or chemical energy from volcanoes and such, and other organisms that eat them or each other. And once you have predators and prey, you're likely to see similar evolutionary strategies such as fast running, camouflage, poison etc.

So all in all, I think there's a pretty good chance that if there is life elsewhere, we'd find it quite recognisable. I've even seen it argued that *intelligent* life has a good chance of looking a bit like us - ie, vertically oriented, with a head at the top and sense organs on it, manipulator appendages half-way down and legs at the bottom. I'm not convinced but I get the argument.

 

[DocZombie]

In other words "Scientists more than happy to make earthshaking predictions they know they'll never have to back up with actual proof."

More like "Media more than happy to mis-quote scientists and get the math wrong" - to whit:

NASA astronomers have estimated that as many as 20 billion of the 100 billion stars in our galaxy have planets that could potentially sustain life.

What the "NASA astronomers" ACTUALLY do is estimate that roughly 1 in 5 (22%) of SUN-LIKE stars in the Milky Way have a rocky planet, 1-2 times the mass of Earth, within the "habitable zone".

As to whether this increases the chances of us finding extraterrestrial life... it helps us narrow the search for life "as we know it"

 

[John the Gamer]

Well then we'd better get on with developing interstellar spacecraft before the aliens steal all the good planets.

 

[1337mokro]

The problem with Alien Life is the problem we face right now. The majority of our species is stupid. Really stupid. Embarrassingly stupid. Sadly these are often the people in charge of things. Communities, cities, politics, religions, committees, nations and so on. Under the capable charge of these people we are basically doomed to go extinct from a massive war, mass extinction event, regression into more primitive technology because of a lack of resources and the list just goes on with possible scenarios where we end up screwing ourselves over before we reach the Star Trek era.\

The same could be said for other life forms on different planets. Sci-fi has the habit of portraying them as one giant culture or one giant collectively agreeing group 99% of the time. That's of course bullshit.

Most likely any other life forms on our level have the same problems and are slowly tilting over the edge into screwing everything up. It is possible other life has already existed way before us, but that they simply never made it out of their solar system because they to destroyed themselves before that point.

Now whilst I am optimistic humanity can cross this hurdle eventually the largest limiting factor to ever meeting alien life forms would be the self limiting factor of a species' stupidity.

 

[HappyBarbarian]

The possibilities for intelligent life is quite exciting. Just think, a few years back we didn't even know for sure if there were any exoplanets. I hope we do discover alien life, and then have this conversation:

Us: So do you guys know about Earth?
Aliens: Yeah man, we've known about you for like a long time
Us: So how come you never tried to contact us?
Aliens: Because your planet is full of assholes


But it does beg the question, "If there are so many possibilities for intelligent life, how come we don't detect any or they don't contact us?"

The Extra Credit guys did a good discussion of that and the whole Drake equation thing earlier this year if you haven't seen it: http://www.penny-arcade.com/patv/episode/funding-xcom-part-1

Just maybe the reason more advanced civilizations don't want to talk to us really is because they think we suck.