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

91–100 of 307 posts

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

#91

Post by phantarch »

danielweber wrote: post #72
phantarch wrote: post #64

Earlier quoted context omitted.

As a counter point, it's always possible that a civilization that developed past where we are now would have been masterful at space travel, but not advanced enough to completely figure out a 1400 light year long journey. We're still having hard times figuring how to get squishy meat sacks to Mars without being irradiated to death or creating a launch vehicle made of lead. Besides the engineering problems there's the…

You don't have to figure out a 1400-ly trip to be here. You just ("just") need to be able to move from one star system to the next. If they took 100 years to get to the next star system 5-ly away and then 500 years to populate that system enough to start a new colonization, that's just ("just") 168,000 years to be here. Given a 2 billion year head start, that's easy.

Even if it only took them 100 years to get to a star system 5 ly away, I would be amazed and impressed by a society that would be okay with investing in and working on at minimum a 105 year mission. Perhaps they live much much longer than we do :)

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

#92

Post by rqebmm »

izend wrote: post #71

Due to the diameter being 60% larger than Earth's diameter, Kepler-452b's ESI score[0] cannot be any higher than 0.85. It might not be the most earth like exo-planet as Kepler-438b[1] has an ESI score of 0.88. [0] https://en.wikipedia.org/wiki/Earth_Similarity_Index [1] https://en.wikipedia.org/wiki/Kepler-438b

In the article they mention that Kepler-438b is likely subject to extreme solar radiation during flares because it's so close to its star. That would make it poor candidate despite scoring high on the ESI scale.

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

#93

Post by qrendel »

Retric wrote: post #81
qrendel wrote: post #56

Earlier quoted context omitted.

To colonize or seed life you don't need to launch huge space vehicles with enough life support to maintain a breeding population, though. You can just launch some kind of self-replicating microbes capable of directing themselves into the forms of life you want to encourage over time. The precise ability to do this would depend on your current state of technology, but we're pretty close to developing full blown synthe…

This might work on a baron world, but any place with a developed ecosystem would likely see these things out competed very quickly do to the massive overhead of needing to survive in space for a long time.

Or they would be engineered with huge advantages against an ecosystem which had never adapted defenses to them (typical of successful invasive species on Earth), and work on timescales much faster than typical evolutionary ones. These would basically be microscopic von Neumann probes, presumably with some kind of self-organizing emergent AI to direct their progress, not just spraying random bacteria everywhere and hoping for the best.

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

#94

Post by danielweber »

camikazeg wrote: post #69
TheOtherHobbes wrote: post #63

Earlier quoted context omitted.

Interstellar travel is perfectly possible if you're not in a hurry. Assuming there's no way to sidestep GR, the real problem is the human lifespan (and attention span.) If our culture moved at 0.1% of the current rate and we lived a thousand times as long, a 1400 year round trip wouldn't be problematic. It's possible to imagine low-energy lifeforms that move that slowly. But they wouldn't be looking for Earth-like pl…

1,400 light years/~45,000mph (the speed of New Horizons) = 23,844,146.8 years of travel time. I guess that wouldn't be impossible, but if you've got a ship that can last that long in interstellar space, then what do you need a planet for? Or for that matter, a star?

You wouldn't try to make a 1400-ly trip, and you would try for a much faster departure than NH did.

There are about 10 stars we know about within 11-ly of earth. A serious attempt to reach one would involve doing slingshots around many bodies in the solar system, probably culminating with a dive to the Sun in order where the major rockets would be fired. (The Oberth effect says you get the most ∆v boost at the point closest to the orbiting body. You cannot logically use the Sun as a passive slingshot because you are trying to leave the solar system.) Getting the speed to 1% of c this way looks entirely reasonable, which gives about a century of travel time.

It would be very expensive, but in a few more centuries society will be a lot richer. This is also something that would only occur after significant colonization within the solar system, and mapping of distant star systems to find good candidate systems.

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

#95

Post by anon4 »

Falcon9 wrote: post #86
staunch wrote: post #82

Earlier quoted context omitted.

I hope they were recording the whole time and upload the videos to YouTube. I can't wait to watch Hannibal on the Pyrenees From Space.mp4

My favorite thought is that they've sent probes millions of years ago and we could send a request to watch some HD surveillance of dinosaurs roaming the Earth. It'll just take ~3k years to receive the requested footage.

Not if you board a spaceship and travel to them at close to light speed! Then you, personally, would just wait a few hours.

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

#96

Post by trhway »

mbil wrote: post #28
lxfontes wrote: post #17

if there is intelligent life there and they point a telescope at us right now, they would be seeing earth ~ 500 years ago. "check out this planet, looks like a promising place once we run out of materials here."

The planet is 1,400 light-years away. They'd be seeing earth at around 600AD.

by the time our today's signal reaches that planet, we ourselves will already be there to listen to it :)

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

#97

Post by Retric »

qrendel wrote: post #93
Retric wrote: post #81

Earlier quoted context omitted.

This might work on a baron world, but any place with a developed ecosystem would likely see these things out competed very quickly do to the massive overhead of needing to survive in space for a long time.

Or they would be engineered with huge advantages against an ecosystem which had never adapted defenses to them (typical of successful invasive species on Earth), and work on timescales much faster than typical evolutionary ones. These would basically be microscopic von Neumann probes, presumably with some kind of self-organizing emergent AI to direct their progress, not just spraying random bacteria everywhere and ho…

Only a tiny fraction of species end up as invasive, because the local ecosystem tends to be better adapted. As to ‘grey goo’ there is fairly good evidence that’s far less possible than you might think.

If you don’t stick with Hydrogen Carbon Nitrogen Oxygen you’re going to have a much harder time finding what you need to grow on earth. For extra solar stuff even those might be hard to find.

If you do stick with HCNO it's hard to get a leg up on nature without simply making a few minor improvements which has limited value outside specific situations. There are also a lot of tradeoffs with binding energy etc.

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

#98

Post by Zelphyr »

qq66 wrote: post #88
staunch wrote: post #82

Earlier quoted context omitted.

I hope they were recording the whole time and upload the videos to YouTube. I can't wait to watch Hannibal on the Pyrenees From Space.mp4

You'll have to wait 6000 years to see it on YouTube: 1500 for them to hear about YouTube and 4500 for them to upload (assuming TCP)

Sheesh. I can't believe after 6000 years TCP is still in use.

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

#99

Post by rm_-rf_slash »

qq66 wrote: post #88
staunch wrote: post #82

Earlier quoted context omitted.

I hope they were recording the whole time and upload the videos to YouTube. I can't wait to watch Hannibal on the Pyrenees From Space.mp4

You'll have to wait 6000 years to see it on YouTube: 1500 for them to hear about YouTube and 4500 for them to upload (assuming TCP)

That might be the funniest thing I've ever read on HN.

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

#100

Post by jessaustin »

phantarch wrote: post #91
danielweber wrote: post #72

Earlier quoted context omitted.

You don't have to figure out a 1400-ly trip to be here. You just ("just") need to be able to move from one star system to the next. If they took 100 years to get to the next star system 5-ly away and then 500 years to populate that system enough to start a new colonization, that's just ("just") 168,000 years to be here. Given a 2 billion year head start, that's easy.

Even if it only took them 100 years to get to a star system 5 ly away, I would be amazed and impressed by a society that would be okay with investing in and working on at minimum a 105 year mission. Perhaps they live much much longer than we do :)

If they lived much longer, comparisons on earth would lead one to expect they'd be much slower to get anything done. Small burrowing rodents that live a couple of years hit the ground running, build extensive dens, and reproduce before they're a year old. OTOH giant tortoises never actually do anything except walk around slowly.
Post reply on HN