Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

nasa.gov

Post reply on HN
Print view View original

31–40 of 307 posts

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#31

Post by ginko »

qrendel wrote: post #24
phantarch wrote: post #5

At 2 billion years older than Earth, I can't begin to imagine what kinds of things could possibly be living on this planet. Given, of course, that it's got the right ingredients for life to arise. What if it's suffered huge extinctions recently? What if there's a domineering species out to conquer the planet just like humans? What if there's a society there more sophisticated than us? It's a very exciting discovery.

I propose it's unlikely that any technological civilizations more advanced than our own have existed on this planet in the past few billion years, otherwise some subgroup of their species would likely have seeded the local universe with life (it's only ~1400 lightyears away) and they would be here instead of us. Unless of course the panspermia hypothesis is correct and that is indeed where life on Earth came from.

It could also be that there was a technologically advanced civilization which destroyed itself.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#33

Post by svachalek »

FailMore wrote: post #6

What's next??? How do we find out if there is life?

I think the basic procedure is to see what chemical signatures can be observed when the planet passes in front of its star (I believe all Kepler-discovered planets do, it's how it finds them) and then try to infer if those could have occurred through purely physical/chemical reactions or if some form of "life" had to be involved.

But, consider that there are a few places in our own solar system that "could" support life, probably with more confidence than we have in this planet so far, and yet the question is still wide open. I wouldn't expect a firm answer for many decades to come.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#34

Post by camikazeg »

uptown wrote: post #19
sktrdie wrote: post #18

Meh, given the hype for this press-release, I was hoping for something more extraordinary frankly. Not that finding other exoplanets isn't amazing, just that we're all waiting to find out whether we are alone or not in the universe. Finding out that other advanced civilizations exist out there would bring such an amazing new meaning to life. If I could ask for one wish, it would be to find out if we're alone or not.…

Read: "Where are all the aliens?" http://qz.com/452452/where-are-all-the-aliens/ "We’re rare, we’re first, or we’re fucked."

Can't interstellar travel just be impossible?

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#36

Post by dr_zoidberg »

peeters wrote: post #20
jpreiland wrote: post #10

To rephrase another comment in the other submission - how do we know/can we infer so much about a planet so far away when we are just now getting reasonable pictures of Pluto? Looking at the images (aside from the artist interpretation), it looks like they're just guessing based on size and location?

One thing to keep in mind is that there is one thing that happens with exoplanets that can never happen with Pluto: the planet can pass between its star and us (i.e. eclipse the star). This gives a lot of information about the planet's composition, because light from the star will scatter/change color according to the planet's composition. See this image: http://seagerexoplanets.mit.edu/images/transitschematic.gif .…

As I understand, star transits by Pluto helped to better estimate its size before NH. But as you said, it's complicated to get a full spectrographic analisys of its atmosphere this way.

Kepler is a mission that mostly works with photometric measurements of planet transits in front of their stars.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#37

Post by lucozade »

phantarch wrote: post #5

At 2 billion years older than Earth, I can't begin to imagine what kinds of things could possibly be living on this planet. Given, of course, that it's got the right ingredients for life to arise. What if it's suffered huge extinctions recently? What if there's a domineering species out to conquer the planet just like humans? What if there's a society there more sophisticated than us? It's a very exciting discovery.

The engineer in me says that it's overwhelmingly likely that there's nothing alive there.

The little boy in me so wants me to be wrong.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#38

Post by phkahler »

How big is it? They have 2 numbers:

>> Kepler-452b is 60 percent larger in diameter than Earth and is considered a super-Earth-size planet.

And then:

>> Kepler-452 is 6 billion years old, 1.5 billion years older than our sun, has the same temperature, and is 20 percent brighter and has a diameter 10 percent larger.

I noticed the lack of "b" on that second one, but they seem to be talking about a single planet.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#39

Post by goodcanadian »

valarauca1 wrote: post #26
TTPrograms wrote: post #21

Does anybody know what the path is to performing some kind of spectroscopy on this planet? Detecting molecules that might indicate life - water, ozone?

When the planet passes in front of its host star, you can measure the change in the stars spectrum, the new chemicals that aren't normally present in a star are assumed to be the planet's. Telescopes that can do this are still a tiny bit away reality I think.

This can be done now with bright enough stars. The trouble is that the stars in the Kepler field are typically very far away, and thus not really bright enough to do these sorts of studies. Spectroscopic observations of exoplanets have occurred with nearer and brighter targets.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#40

Post by DuskStar »

qrendel wrote: post #24
phantarch wrote: post #5

At 2 billion years older than Earth, I can't begin to imagine what kinds of things could possibly be living on this planet. Given, of course, that it's got the right ingredients for life to arise. What if it's suffered huge extinctions recently? What if there's a domineering species out to conquer the planet just like humans? What if there's a society there more sophisticated than us? It's a very exciting discovery.

I propose it's unlikely that any technological civilizations more advanced than our own have existed on this planet in the past few billion years, otherwise some subgroup of their species would likely have seeded the local universe with life (it's only ~1400 lightyears away) and they would be here instead of us. Unless of course the panspermia hypothesis is correct and that is indeed where life on Earth came from.

Apparently it has a diameter 60% larger than that of the Earth, and so if we assume it has the same density as the Earth it would have about 16m/s^2 gravity on the surface, and an orbital velocity of around 12km/s @ ~1000km (in comparison to the Earth, where a 1000km circular orbit is closer to 7km/s).

This means that merely achieving orbit would be approximately as difficult as launching a probe on a Hohmann transfer orbit to Mars is. (Except that such a launch vehicle would need nearly twice the thrust/weight, cutting down the mass ratio even further.) It is not unreasonable to think that a species on such a planet would have never seriously developed space travel.

Post reply on HN