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Seven earth-sized planets discovered circling a star 39 light years from Earth

nature.com

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Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#471

Post by Exofunctor »

maverick_iceman wrote: post #446
blueprint wrote: post #217

Earlier quoted context omitted.

I'm talking about establishing a self-sufficient colony somewhere other than Earth. We have a major crisis on our hands. And few are even willing to consider let alone research and confirm that we're talking about an extinction event much sooner than we thought, maybe on the order of just a couple years out. Problem is, we don't know. Bigger problem is, we're not doing anything about it.

Lots of good reasons to establish a space colony, fleeing the earth is not one of them. By this sort of argument you actually discredit the idea of space exploration.

> fleeing the earth is not one of them

Why not? If a big asteroid is going to hit earth (for example), fleeing is a pretty reasonable response. It's also a reasonable defense against technobiological hazards.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#472

Post by sbierwagen »

kcorbitt wrote: post #47
e0m wrote: post #33

To get a spacecraft there it would take: Accelerating at 1g the 1st half, and decelerating at 1g the 2nd half, the traveler would experience 7.3 years of time. For observers it would take 41.8 years at a max speed of 0.998c If you had a near perfect hydrogen -> helium fusion engine, it'd take about 6 million tons of fuel (about the mass of the Pyramids of Egypt or 2,000 Saturn V rockets)

That actually sounds... more plausible than I would have expected. Like, doable with technology I can imagine being within reach in the next 50 years even if we don't achieve any currently-unforseen breakthroughs.

EDIT: My math was totally wrong. 10 trillion dollars, 0.1x world GDP. (Still a lot of money though) Leaving the old text below so the replies make sense.

---

To move 6,000,000 megatons of fuel into low earth orbit would take 111,111 Falcon Heavy launches, at a total cost of $10,000,000,000,000 dollars. (10 quadrillion dollars, 93x world GDP)

Something that takes the total global economic output of the planet a century just to lift the fuel into orbit doesn't read as plausible in the next 50 years to me.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#473

Post by grondilu »

maverick_iceman wrote: post #440
blueprint wrote: post #72

Earlier quoted context omitted.

Which begs the question, why haven't we at least even tried to have done anything like this already? Do we really need to repeatedly spend comparable amounts of money on yet another dramatic TV special about humans traveling to Mars, as narrated by a favored celebrity? We really are running out of time. And it almost seems like it's pre-determined to happen. :\

Politics, specifically the PTBT[1]. Otherwise Project Orion[2] would be a reality now. [1] https://en.wikipedia.org/wiki/Partial_Nuclear_Test_Ban_Treat... [2] https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...

Project Daedalus seems more appropriate for interstellar travel:

https://en.wikipedia.org/wiki/Project_Daedalus

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#474

Post by Mtinie »

scardine wrote: post #447
gydfi wrote: post #400

Earlier quoted context omitted.

Would they? I mean, we can see geological features on our moon, and our tides are orders of magnitude away from being rock-tearing events. I mean, the moon is small, but... how close do these planets approach, anyway?

The moon is not that small, it is 27% of earth's size. Any other satellite in the solar system is way smaller compared to the planet they orbit. I dare to say that earth and moon are twin planets instead of a planet and a satellite.

@ConceptJunkie

> The Moon is about 2% of Earth's mass, not 27%.

2% of mass, yes, but also 27% of the diameter.

You are both right.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#476

Post by angry_octet »

scardine wrote: post #447
gydfi wrote: post #400

Earlier quoted context omitted.

Would they? I mean, we can see geological features on our moon, and our tides are orders of magnitude away from being rock-tearing events. I mean, the moon is small, but... how close do these planets approach, anyway?

The moon is not that small, it is 27% of earth's size. Any other satellite in the solar system is way smaller compared to the planet they orbit. I dare to say that earth and moon are twin planets instead of a planet and a satellite.

Radius 27%, mass 1.2%.

http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#477

Post by ashark »

tempestn wrote: post #399
blueprint wrote: post #312

Earlier quoted context omitted.

I said nothing about war..?

There's no other conceivable extinction event that could occur "a couple years out". If you're talking climate change, then I agree that's a major problem, but on the order of at least decades.

Plus climate change would have to get pretty incredibly bad for, say, Mars to start looking easier to live on than Earth.

That's the problem with colonization as an Earth back-up—even Antarctica and the Sahara Desert are more livable than any other body in the Solar System, by a long shot. Another Snowball Earth or a heavily desertified Earth would still be preferable to Mars. Throw in a fair amount of radiation, even—still better.

Cuts down significantly on the sorts of events for which a Martian back-up world is preferable to a shelter-in-place strategy.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#478

Post by throwanem »

yellowapple wrote: post #314
throwanem wrote: post #212

Earlier quoted context omitted.

In which Firefox version?

Worked for me in Firefox for Android (53, Aurora build).

Maybe it's a prerelease feature, or maybe Firefox is falling back on a capability that at least some desktop OSes don't have.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#479

Post by mozumder »

sbierwagen wrote: post #472
kcorbitt wrote: post #47

Earlier quoted context omitted.

That actually sounds... more plausible than I would have expected. Like, doable with technology I can imagine being within reach in the next 50 years even if we don't achieve any currently-unforseen breakthroughs.

EDIT: My math was totally wrong. 10 trillion dollars, 0.1x world GDP. (Still a lot of money though) Leaving the old text below so the replies make sense. --- To move 6,000,000 megatons of fuel into low earth orbit would take 111,111 Falcon Heavy launches, at a total cost of $10,000,000,000,000 dollars. (10 quadrillion dollars, 93x world GDP) Something that takes the total global economic output of the planet a centur…

You wouldn't gather that fuel from earth.. you'd gather it from an icy asteroid or comet or moon (Europa).

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#480

Post by pmoriarty »

hackuser wrote: post #359
pcrh wrote: post #185

Earlier quoted context omitted.

Melancholia by Lars von Trier is another great movie about the earth colliding with another planet. http://www.imdb.com/title/tt1527186/

An excellent, incredibly beautiful film, beyond the topical plot point.

Beautiful, but super, super, boring -- with an extra helping of boring on top.
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