How Many "Earths" Are In The Galaxy? Try Billions

[Fanghawk]

How Many "Earths" Are In The Galaxy? Try Billions

It's great that NASA is finding Earth-like planets such as Kepler-452b, but scientists suspect many more exist in our galaxy alone.

Yesterday was a very exciting day for <a href=http://www.escapistmagazine.com/tag/view/space>space devotees after <a href=http://www.nasa.gov/press-release/nasa-kepler-mission-discovers-bigger-older-cousin-to-earth>NASA revealed the existence of Kepler-452b. Despite being 60 percent larger than our world, Kepler-452b is basically an "older, bigger cousin to Earth" that holds <a href=http://www.escapistmagazine.com/news/view/140391-NASA-Believes-Alien-Life-Will-Be-Found-In-Next-10-To-20-Years>intriguing prospects for alien life. But if NASA scientists are right, Kepler isn't alone: according to researcher Natalie Batalha it's highly probable that a billion "Earths" exist in our galaxy alone. And that's a conservative estimate.

"[Previous estimates] suggest that 15-25% of stars host potentially habitable planets," Batalha explained. "So how does that translate to the number of planets in the galaxy? M, K, and G dwarfs comprise about 90% of the stars in the galaxy. Conservatively speaking, if 15% of stars have a planet between 1 and 1.6 times the size of Earth in the Habitable Zone, then you'd expect 15% of 90% of 100 billion stars to have such planets. That's 14 billion potentially habitable worlds."

We can go a step further and focus entirely on G-type stars like our own sun. If we're looking at our solar neighborhood of 33 light years, 20 out of 357 stars are G-type. Based on Batalha's math, that means roughly a billion "Earths" in the galaxy have yellow suns like ours (although <a href=https://en.wikipedia.org/wiki/G-type_main-sequence_star>that's technically just a trick of Earth's atmosphere).

Now to be clear, even if we're being modest and stick with that one billion figure, it doesn't mean colonists can settle on them. Venus is technically a "habitable" planet by these standards, and in case you weren't aware, <a href=https://en.wikipedia.org/wiki/Venus>it's not a pleasant place for anyone who likes breathing. And we can only make educated guesses about worlds like Kepler-452b, especially since its increased size might have incompatible gravity.

That being said, each discovered world still offers a wealth of unique knowledge, and might even have life forms of their own. Kepler-452b has been in its habitable zone for 6 billion years, longer than the age of our Sun. Who knows what secrets these billions of worlds might offer, even if they're not the most ideal vacation destinations?

Until we know for sure, feel free to check out the images <a href=http://www.nasa.gov/press-release/nasa-kepler-mission-discovers-bigger-older-cousin-to-earth>NASA has released on Kepler-452 while we dream of possibilities.

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Source: Washington Post

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[Something Amyss]

Venus is technically a "habitable" planet by these standards, and in case you weren't aware, <a href=https://en.wikipedia.org/wiki/Venus>it's not a pleasant place for anyone who likes breathing.

Or if breathing's not your thing, there's also the "being cooked to death" issue.

Neil deGrasse Tyson has made several good arguments for why the habitable zone is a misnomer, but this takes it from the other side of things. Then again, most of even our own planet is hostile to human life...

...just not as bad as Venus. Or even close.

 

[Asclepion]

And the Fermi Paradox once again rears it's head.

 

[Clive Howlitzer]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

 

[Oakleigh]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

Amen to that. Just seems like we are burning our luck the more time we spend not colonizing other foreign bodies. Maybe Apophis when it comes around again will be a wake up call.

 

[Clive Howlitzer]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

We don't know how, not really. Sending some guys on a 2 week trip to the nearest rock is a far cry from a persistent and independent human presence off Earth.

The truth is that we just don't have the technology yet.

I know, it was mostly just a hopeful comment. If only more money were allocated to R&D.

 

[Mikeybb]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

We don't know how, not really. Sending some guys on a 2 week trip to the nearest rock is a far cry from a persistent and independent human presence off Earth.

The truth is that we just don't have the technology yet.

Very true.
At least knowing there's something out there might inspire people to keep trying to develop that technology (or be more amenable to paying for the funding it's going to need.

An aside but I find news like this hopeful.
However massively distant from ever having an appreciable impact on not only my life but even that of any grandchildren I happen to leave behind, however beyond our reach it may be for now, it's the knowing there are other worlds that sit in an area we know can sustain life that makes it so.

Of course, it helps not to then start dwelling on the Fermi Paradox (as brought up by Asclepion) if you want to keep that shiny, hope for the future fueled smile on your face.

 

[Fox12]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

We don't know how, not really. Sending some guys on a 2 week trip to the nearest rock is a far cry from a persistent and independent human presence off Earth.

The truth is that we just don't have the technology yet.

Very true.
At least knowing there's something out there might inspire people to keep trying to develop that technology (or be more amenable to paying for the funding it's going to need.

An aside but I find news like this hopeful.
However massively distant from ever having an appreciable impact on not only my life but even that of any grandchildren I happen to leave behind, however beyond our reach it may be for now, it's the knowing there are other worlds that sit in an area we know can sustain life that makes it so.

Of course, it helps not to then start dwelling on the Fermi Paradox (as brought up by Asclepion) if you want to keep that shiny, hope for the future fueled smile on your face.

Bare in mind the ancients would lie awake at night, looking toward the moon, thinking "I want to go there." It was impossible for them too, but now we have it. We take that for granted, I think. Eons from now, we'll probably seem like primitive dreamers too.

I'm quite optimistic.

 

[Metadigital]

Bare in mind the ancients would lie awake at night, looking toward the moon, thinking "I want to go there." It was impossible for them too, but now we have it. We take that for granted, I think. Eons from now, we'll probably seem like primitive dreamers too.

I'm quite optimistic.

Keep in mind that we can't see the universe through our own brilliance anymore, and if we do stay up late at night, it's probably to post on message boards like this.

 

[Fox12]

Bare in mind the ancients would lie awake at night, looking toward the moon, thinking "I want to go there." It was impossible for them too, but now we have it. We take that for granted, I think. Eons from now, we'll probably seem like primitive dreamers too.

I'm quite optimistic.

Keep in mind that we can't see the universe through our own brilliance anymore, and if we do stay up late at night, it's probably to post on message boards like this.

If humanity has changed, it's only for the better. I don't believe in God, but I do believe humanity can achieve literally any goal, given enough time and resources. Not only that, but the rate at which we advance has increased too. On e you cross a certain threshold human progress becomes explosive. You can mock message boards, but it's a result of the Internet, one of the most important creations in human history. Don't knock it, man.

 

[FalloutJack]

And the Fermi Paradox once again rears it's head.

More like gets kicked in the balls. The evidence suggests there's plenty of reason for them to be out there somewhere. We haven't seen them because it's a Big McLargeHuge universe, and our ability to look around it is limited. The ability to just happen upon the right dot in space at the right time (compensating for the time differential) with the right equipment to pick up images you can't write off as nothing or coincidence is NOT an easy thing to come by yet. We have GREAT equipment. Still miniscule by comparison to the distances and physics involved. Fermi was just being kind of dickish.

 

[Erttheking]

Can we stop keeping all our eggs in one basket and get off this dingy rock then?

I second this. My dream has always been to die on another planet (Though at this point I'd settle for the moon). We've got Mars (Decent size and not that cold), Europa (Water) and Titan (All that Helium-3 that would be very valuable in fusion, which an engineering friend of mine says is probably only a couple of decades away) in this star system alone. Hell Venus IS colonizable if we can manage to terraform it (Which would no doubt be a very long and expensive process, but another planet to live on would be worth it in the long run)

We seriously need to set some sort of inter-planatary transport down. And if not, I'll sign up for a generation ship.

 

[Metadigital]

If humanity has changed, it's only for the better. I don't believe in God, but I do believe humanity can achieve literally any goal, given enough time and resources. Not only that, but the rate at which we advance has increased too. On e you cross a certain threshold human progress becomes explosive. You can mock message boards, but it's a result of the Internet, one of the most important creations in human history. Don't knock it, man.

If only this were true.

I wasn't knocking message boards. I was knocking light pollution.

Your word choice about human progress being "explosive" was spot on, though. We are at the dawn of one of the world's greatest mass extinction events, and we are its cause. Over the next 200 years we're going to see a minimum of about 75 feet in rising sea waters. Each day of industrial growth, market expansion, and suburban development brings us exponentially closer to an inhospitable world. The fact is that we are running out of both time and resources, and the situation is a hell of a lot worse than politicians (and even public scientists) are willing to admit.

So, no, not everything has changed for the better, and it's exactly this arrogance that is driving this extinction machine.

 

[zumbledum]

And the Fermi Paradox once again rears it's head.

more of the interesting point than paradox now i mean so hany holes and explanations have been put in it