Our Galaxy May Have 50 Billion Exoplanets–and It’s Still Making More

**Descensus** · 02-27-2011 07:40 AM

Our Galaxy May Have 50 Billion Exoplanets–and It’s Still Making More | 80beats | Discover Magazine

Originally Posted by Discover Magazine

Young. Old. Scalding hot. Icy cold. Terrestrial midgets. Gas giants. As the cavalcade of planets spotted beyond our solar system continues to grow, we get to see worlds of all sorts—and we get to speculate on the staggering number of exoplanets that might inhabit just our own galaxy.

Today’s first piece of otherworldly news involves baby exoplanets. Astronomer Christian Thalmann says his team may have spotted planets in the process of forming around three different stars, the first time scientists have spotted the process in action.

An infant star forms from a collapsing cloud of dust and gas and gathers a dense, flat disk of material that rotates with the star like a record album. The material in the disk will eventually clump up into nascent planets. Theoretical models of planet formation predicted that those protoplanets should suck up more gas and dust with their gravity, clearing a wide gap in the otherwise solid disk. [Wired]

Peering at young stars like T Chamaeleontis (T Cha) LkCa15 and AB Auriga, Thalmann and colleagues saw those telltale gaps in the dusty rings (their study is forthcoming in the Astrophysical Journal Letters). The stars are much like our own sun, so these pictures of infant solar systems could resemble what our own looked like as a baby. But though the stars are nearby in cosmic terms—T Cha lies just 350 light years away—the gaps are faint enough that it’s difficult to tell for certain if newly forming planets, and not the influence of binary stars or other objects, are creating them.

If Thalmann’s team is right, catching the birth of new worlds would be a great scientific coup. Our galaxy, however, isn’t exactly hurting for planets.

Earlier this month came the big announcement from NASA’s Kepler mission, when its scientists announced 1,200 new potential planets, including 54 found in the habitable region around their stars. Since then, project science head William Borucki has done a few back-of-the-envelope extrapolations based on Kepler’s findings, and produced some eye-popping planet tallies that he announced at last weekend’s American Association for the Advancement of Science (AAAS) annual conference in Washington: The total number of Milky Way planets could be on the order of 50 billion, with 500 million of those falling in the life-friendly Goldilocks zone.

Borucki and colleagues figured one of two stars has planets and one of 200 stars has planets in the habitable zone… And that’s a minimum because these stars can have more than one planet and Kepler has yet to get a long enough glimpse to see planets that are further out from the star, like Earth, Borucki said. For example, if Kepler were 1,000 light years from Earth and looking at our sun and noticed Venus passing by, there’s only a one-in-eight chance that Earth would also be seen, astronomers said. [AP]

Kepler—humankind’s best planet-hunter—surveys an area that accounts for just one-four-hundredth of the sky. And yet it produces a bonanza of worlds, the implications of which got extraterrestrial life enthusiasts buzzing at the same AAAS meeting. Howard Smith of the Harvard-Smithsonian Center for Astrophysics argued that the great distances and relative harshness of the universe makes humanity a de facto loner. Even if there are other civilizations, he said, we could never reach them in person or by electronic communication (at least, not without a hundred generations of humans awaiting the response). But Seth Shostak of the SETI Institute unsurprisingly saw the sunny side of a galaxy overflowing with planets.

Shostak cited an argument that says increases in computer power mean we’ll be able to analyse far more planetary data than has been possible until now. He was confident that within 24 years we would detect an alien civilisation. “There are maybe 10 21 Earth-like planets out there,” he said. “Believing there aren’t ETs is believing in miracles.” He bet the audience that we’d find ET within our lifetime or else he’d buy us a cup of Starbucks. [New Scientist]

I rarely turn down a strong cup of joe, but I hope Shostak is proved correct.

**kalesh** · 02-27-2011 09:13 AM

And scientists still stay we are the only intelligent species in the universe. Yeah right.

**DrunkenArse** · 02-27-2011 11:32 AM

What scientist says that? Seriously? It's the religious people that generally say we're the only intelligent species. First off, many other species here on earth qualify as intelligent in certain ways and it's science that's been figuring that out. More to the point though, consider the scientific perspective on life: Chemical reactions caused replicating molecules upon which natural selection acted to create the modern diversity of life which we see. What would lead you to believe that the scientific perspective on life does anything but suggest (almost guarantee) life on other planets?

Seriously dude, do you even know what a scientist is or how science operates? Do you know what evolution is? abiogenesis?

Contrast with the view that some sky-daddy whipped us up special and sent his only begotten son to die so that he could forgive us for our sins which he designed us to commit. What about all the other species that are pretty much guaranteed to exist on all the other planets that are also not at the center of the universe?

**juroara** · 02-28-2011 06:49 PM

I just wanted to say, I can't even comprehend 500 million! That number is too big to imagine.

**MindGames** · 02-28-2011 09:30 PM

Originally Posted by kalesh

And scientists still stay we are the only intelligent species in the universe. Yeah right.

Wait, we're an intelligent species?

**nina** · 02-28-2011 10:11 PM

Maybe sky daddy was just an alien.

Who wouldn't love to travel to a distant, unclaimed planet and declare yourself god and creator and get all it's inhabitants to worship you.

**DuB** · 03-01-2011 02:27 AM

If the inhabitants were human I'd think about it. Seems sort of pointless to me to rule over things that you can't fuck. Let's be honest, isn't that basically the whole point?

**DrunkenArse** · 03-01-2011 02:37 AM

Intelligence aside, there's a high probability that we're not the only organisms in the universe with orifices...

Just underscoring the difference between "can't" and "don't want to". Call me a pedant.

**kalesh** · 03-01-2011 06:46 AM

I cant put links right now (seven day rule) I will edit when I can.

Now I don't want to argue much. And more and more scientists are accepting the idea that Life may be "out there". But usually that life happens to be bacteria or such.

Originally Posted by PhilosopherStoned

What scientist says that? Seriously?

Yes seriously, just some quotes for reference (you can find more if you wish to):

IT IS unlikely that there is intelligent alien life on other planets as we would have encountered it by now, according to British scientist and astrobiologist Dr Lewis Dartnell.

Howard Smith, a senior astrophysicist at Harvard, made the claim that we are alone in the universe after an analysis of the 500 planets discovered so far showed all were hostile to life.

So I'll leave that as that.

Originally Posted by PhilosopherStoned

It's the religious people that generally say we're the only intelligent species. First off, many other species here on earth qualify as intelligent in certain ways and it's science that's been figuring that out. More to the point though, consider the scientific perspective on life: Chemical reactions caused replicating molecules upon which natural selection acted to create the modern diversity of life which we see. What would lead you to believe that the scientific perspective on life does anything but suggest (almost guarantee) life on other planets?

Tell that to the two dudes above, and others like them.

Originally Posted by PhilosopherStoned

Seriously dude, do you even know what a scientist is or how science operates? Do you know what evolution is? abiogenesis?

Yes I do. I know about both evolution and abiogenesis. And I also know something else. Life Does Not need earth like conditions to thrive. Tell that to those still looking for "earth like planets.

Physicists have created blobs of gaseous plasma that can grow, replicate and communicate - fulfilling most of the traditional requirements for biological cells. Without inherited material they cannot be described as alive, but the researchers believe these curious spheres may offer a radical new explanation for how life began.

And they are still looking for earth like planets??

now for some definitions of science.

1. the systematic observation of natural events and conditions in order to discover facts about them and to formulate laws and principles based on these facts. 2. the organized body of knowledge that is derived from such observations and that can be verified or tested by further investigation. 3. any specific branch of this general body of knowledge, such as biology, physics, geology, or astronomy.

Science alone of all the subjects contains within itself the lesson of the danger of belief in the infallibility of the greatest teachers in the preceeding generation . . .As a matter of fact, I can also define science another way: Science is the belief in the ignorance of experts.

Originally Posted by PhilosopherStoned

Contrast with the view that some sky-daddy whipped us up special and sent his only begotten son to die so that he could forgive us for our sins which he designed us to commit. What about all the other species that are pretty much guaranteed to exist on all the other planets that are also not at the center of the universe?

That argument wont work on someone who couldn't care less about the bible. Look at the ancient religions. check out Ramayana, Mahabharat, etc, look at the text version, not half assed films and you will find references to flying machines, spacecraft, ET and so on. Hell we even had intelligent and technologically advanced monkeys, (as advanced as humans of the time).

**Xei** · 03-01-2011 05:02 PM

Originally Posted by Aquanina

Maybe sky daddy was just an alien.

Who wouldn't love to travel to a distant, unclaimed planet and declare yourself god and creator and get all it's inhabitants to worship you.

Good luck speaking English to a crowd of levitating balls of orange gelatinous material.

**Marvo** · 03-01-2011 05:25 PM

Tell that to the two dudes above, and others like them.

The first person is obiously talking about the planets in our solar system, as in, Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune. The second person is most likely referring to something much more specific, though it's hard to say since you're basically taking their quotes out of context.

Yes I do. I know about both evolution and abiogenesis. And I also know something else. Life Does Not need earth like conditions to thrive. Tell that to those still looking for "earth like planets.

And they are still looking for earth like planets??

It makes more sense to look for planets that can definitely host life as we know it, than to search for life based on an arbitrary definition, since we don't know that definition.

That argument wont work on someone who couldn't care less about the bible. Look at the ancient religions. check out Ramayana, Mahabharat, etc, look at the text version, not half assed films and you will find references to flying machines, spacecraft, ET and so on. Hell we even had intelligent and technologically advanced monkeys, (as advanced as humans of the time).

Those were not monkeys, they were monkeys' ancestors. Also, a caveman drawing a flying object on a wall is not evidence of anything. I can also draw alien spaceships, does that mean I've seen them though?

**Descensus** · 03-01-2011 05:45 PM

Kalesh, do you have citations for the quotes? Throwing them at us and saying "look!" doesn't help.

**Xei** · 03-01-2011 05:54 PM

Originally Posted by Marvo

The first person is obviously talking about the planets in our solar system, as in, Mercury, Venus, Mars, Jupiter, Saturn, Uranus and Neptune. The second person is most likely referring to something much more specific, though it's hard to say since you're basically taking their quotes out of context.

Um well, it's not particularly obvious (it's also wrong). The first guy is actually talking about the galaxy, although he is talking about intelligent life and not life in general. There is a relatively good argument for this, which is that intelligent life could have evolved at any time within the last few billion years, yet it'd only take a time period of the order of a hundred thousand years or so to send messages to the whole galaxy if it were technologically advanced.

I remember the second guy's statements being on the BBC News site last year and he had no real argument.

**kalesh** · 03-01-2011 07:35 PM

Originally Posted by BLUELINE976

Kalesh, do you have citations for the quotes? Throwing them at us and saying "look!" doesn't help.

I know I know, give me 1 more day. I have been here 6 days. I need to be here 7 days to post the link.

**Descensus** · 03-01-2011 07:43 PM

Originally Posted by kalesh

I know I know, give me 1 more day. I have been here 6 days. I need to be here 7 days to post the link.

Ah, forgot about that.

**Marvo** · 03-01-2011 08:00 PM

Originally Posted by Xei

Um well, it's not particularly obvious (it's also wrong). The first guy is actually talking about the galaxy, although he is talking about intelligent life and not life in general. There is a relatively good argument for this, which is that intelligent life could have evolved at any time within the last few billion years, yet it'd only take a time period of the order of a hundred thousand years or so to send messages to the whole galaxy if it were technologically advanced.

That's actually a brilliant argument. Interesting. There could of course still be intelligent life somewhere in the galaxy, but we probably won't know before we destroy our selves.

**Xei** · 03-01-2011 08:35 PM

Yeah, it does jar with me that one. I always thought that life would be pretty likely (within our own solar system even, there are places well it could well have arisen, including Mars and Europa), and that intelligent life occurring after life would still be pretty likely (although perhaps the lateness of the Cambrian explosion, and the small number of species with free limbs for manipulation, point away from this). All it would take would be one intelligent species with the technology to create self-replicating probes, which only seems a geological heartbeat away from we are, and very soon the whole galaxy would have evidence of contact.

Of course, this says nothing about the amount of intelligent life in the universe, which would still mean around 100 billion intelligent life forms if only one planet per galaxy tended to have life (although of course we have no guarantee of this).

**cmind** · 03-01-2011 10:23 PM

Originally Posted by Xei

All it would take would be one intelligent species with the technology to create self-replicating probes, which only seems a geological heartbeat away from we are, and very soon the whole galaxy would have evidence of contact.

But by the same token, if those probes landed on Earth, they would be buried deep in the crust within a few million years, so we would never know they were here.

**Xei** · 03-01-2011 10:57 PM

Clearly the probes would not be sent to crash into the planet, they would presumably be sent to orbit it and transmit information.

**Spartiate** · 03-01-2011 11:11 PM

This is called the Fermi paradox. Wiki has a neat article on it and its ramifications.

I think that the most likely explanation is that civilizations are destroyed before they can reach significant interstellar capabilities.

**Xei** · 03-01-2011 11:16 PM

Bearing in mind we're talking about a very large number of potential worlds though. Is it really an almost certainty that every life form is stupid enough to destroy itself? Seems extremely anthropocentric.

**cmind** · 03-01-2011 11:38 PM

Originally Posted by Xei

Clearly the probes would not be sent to crash into the planet, they would presumably be sent to orbit it and transmit information.

But if we're taking license with the intentions of aliens, then I could just as easily say that there are probes out there in near Earth space, but they're maintaining radio silence until they determine we're "ready" to hear them.

The Fermi so-called paradox is merely a result of people not comprehending astronomical distances and time scales.

**Xei** · 03-01-2011 11:44 PM

You say that but you haven't adequately responded to the point at hand here.

The point about us being 'ready' is extremely wishy-washy. How could a space probe have this much intelligence and observational power? And even if it were plausible, for your argument to work you have to assert that every single intelligent lifeform would have come to the same conclusion and used the same approach which is just silly.

**cmind** · 03-02-2011 12:08 AM

Originally Posted by Xei

You say that but you haven't adequately responded to the point at hand here.

The point about us being 'ready' is extremely wishy-washy. How could a space probe have this much intelligence and observational power? And even if it were plausible, for your argument to work you have to assert that every single intelligent lifeform would have come to the same conclusion and used the same approach which is just silly.

Are you, or are you not, asserting that there's no (or little) intelligent life in the universe because we haven't been contacted by a probe?

Have you considered these factors:
- the time a probe would sit idle in our solar system before we came along, versus its durability? All engineered systems fail eventually. Do you have reason to believe that intelligent aliens could create probes that last millions of years?

- the sheer number of star systems? Can we honestly expect some sort of von Neumann probe scheme to penetrate every single system? Really?

- are there astronomical events that destroy the probes before they spread too far? Do we really know how often gamma ray bursts happen in this galaxy?

- that YOU may be anthropomorphizing the aliens? How do we know that aliens millions of years ahead of us even care about exploring space? And no, there's no default position here. You understanding advanced aliens is about as likely as an ant understanding Shakespeare.

**Xei** · 03-02-2011 12:27 AM

Originally Posted by cmind

Are you, or are you not, asserting that there's no (or little) intelligent life in the universe because we haven't been contacted by a probe?

Galaxy.

Have you considered these factors:
- the time a probe would sit idle in our solar system before we came along, versus its durability? All engineered systems fail eventually. Do you have reason to believe that intelligent aliens could create probes that last millions of years?

Do you have a reason not? Are they going to get space rust?

- the sheer number of star systems? Can we honestly expect some sort of von Neumann probe scheme to penetrate every single system? Really?

You've ignored the point I made again; we're not just talking about a single civilisation which might have made a mistake (although again you're not explaining why this is so obvious anyway), we're talking about the law of large numbers.

- are there astronomical events that destroy the probes before they spread too far? Do we really know how often gamma ray bursts happen in this galaxy?

You tell me?

- that YOU may be anthropomorphizing the aliens? How do we know that aliens millions of years ahead of us even care about exploring space? And no, there's no default position here. You understanding advanced aliens is about as likely as an ant understanding Shakespeare.

Well, curiosity is certainly a requirement. And again, the law of large numbers. Plus the fact that life does not instantaneously jump to a highly advanced state.