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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

#561

Post by nickhalfasleep »

nabla9 wrote: post #333
jerf wrote: post #167

Earlier quoted context omitted.

The debate rages. The problem is that one side of the planet is essentially exposed to space and thus tends to be at cosmic background temperature, and the other side exposed to the star. It is thought by a lot of people that anything volatile enough to be a gas, ever (so, including water), would rapidly end up migrating over to the frozen side, so even if the planet started with the right mix of water and whatever o…

If water freezes on the dark side, moisture in the atmosphere would probably move from warm to dark side and fall down permanently as a snow gradually removing liquid water. If the oxygen and nitrogen freezes and snows down in the dark side (-220 C or so), the warm side can't have atmosphere either. Unless there is some way tidally locked planet can have stable air or sea convection between the sides. I don't think t…

If there is enough gravitational pull, the planet itself might be warmed by geologic flexing like Io.

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

#562

Post by daveguy »

fsloth wrote: post #309
MrZongle2 wrote: post #133

Earlier quoted context omitted.

Most likely several hundred quatloos' worth, I'm guessing. :D Edit: Oh, HN, you are so humor impaired sometimes.

Voting is a mechanism to signal whether the comment adds anything to the discussion. Star Trek references really don't add anything to an actual scientific discovery. I would much rather read actual engineering rather than entertainment driven thought.

I took the post as commentary on the engineering feasibility of the parent post.

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

#563

Post by thangalin »

pwython wrote: post #384
kitrose wrote: post #360

Earlier quoted context omitted.

Can someone explain to me why we don't replicate some of these key platforms like the Hubble and James Webb ST? It seems like the major limitation for discovery is getting enough observation time for whatever certain point in the sky that scientists are researching. Why don't we launch a second copy of James Webb?

A Hubble or James Webb is easily a billion dollar effort, making it THE major limitation for discovery. No one is investing that sort of money for no return. Honestly, even if they did, it would be frowned upon considering the more important humanitarian investments at hand.

"In 1970, a Zambia-based nun named Sister Mary Jucunda wrote to Dr. Ernst Stuhlinger, then-associate director of science at NASA's Marshall Space Flight Center, in response to his ongoing research into a piloted mission to Mars. Specifically, she asked how he could suggest spending billions of dollars on such a project at a time when so many children were starving on Earth."

I encourage you to read his reply.

http://www.lettersofnote.com/2012/08/why-explore-space.html

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

#565

Post by battlebot »

mjevans wrote: post #458
Balgair wrote: post #332

Earlier quoted context omitted.

The engineering issues are really tough, though surmountable. Currently, we just can't engineer the parts that will last that long in hard vacuum. Mostly because we can't test in that environment easily. Also, what do you do when all the light bulbs have burned out or gone haywire, what does that fault-tree look like for the billion and one parts on the craft? For a short journey of ~7 years, it's not a very big deal…

With a round trip parts delivery time OF a generation, and a communications delay of almost a decade (two for duplex), I don't see any reason not to classify such a mission as a short-range 'generation ship' / complete colony effort. Getting our 'eggs' out of a single cosmic basket is really important, however I think we need to at least take the baby-crawl to establishing an outpost in the asteroid belt. That would…

I'm for it, but we seem to be held up by the fact that roughly 70% of humanity is still living in the 15th century.

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

#568

Post by [deleted] »

zhan_eg wrote: post #535
dcposch wrote: post #496

Earlier quoted context omitted.

> The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. this reminds me of one my favorite films ever. it is just four minutes long http://www.erikwernquist.com/wanderers/

Thank you, this is truly amazing. For all the people interested in any way in space - watch this :)

[deleted]

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

#569

Post by smaddox »

dcposch wrote: post #496
dmix wrote: post #6

My favourite part of the press release: > The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. > In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water cou…

> The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. this reminds me of one my favorite films ever. it is just four minutes long http://www.erikwernquist.com/wanderers/

Have you seen Reid Gower's Sagan Series?

http://saganseries.com

It similarly combines HD cinematography with Carl Sagan's narration. It's not CG like this, but the overall quality is extremely high (at least after the first chapter).

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

#570

Post by yongjik »

BinaryIdiot wrote: post #336
neaden wrote: post #301

Earlier quoted context omitted.

Isn't part of the problem that any ship capable of interstellar travel is also capable of being turned into a WMD? I imagine a lot of people would get really nervous if someone for instance parked a bunch of radioactive material in low earth orbit, and even with fusion there would be the fear that someone could turn the ship around.

To be fair kinetic bombardment is stupid easy to do once you can put stuff into orbit. Put a few, 20 foot long tungsten rods into orbit and you can effectively nuke, without radiation, any location that you orbit over [1]. Sure this is a problem but it's one that already exists today, not necessarily only when we start building space craft in orbit. [1] https://en.wikipedia.org/wiki/Kinetic_bombardment

> ...a 6.1 m × 0.3 m tungsten cylinder impacting at Mach 10 has a kinetic energy equivalent to approximately 11.5 tons of TNT (or 7.2 tons of dynamite).

Well, that's a bit underwhelming. Sounds a bit like Russian polonium tea, that is, less like a matter of efficiency, and more like showing off the sheer extravaganza of killing somebody in the most colorful, expensive way.

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