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

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

nature.com

Post reply on HN
Print view View original

671–680 of 754 posts

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

#671

Post by alex_duf »

nie wrote: post #668

When I looked at the image[1] illustrating size/mass/orbit periods of TRAPPIST-1, I was fascinated by the orbit period: 6.10 days, for example, for planet e! Suppose we were to be able to stand on that planet and stargaze outwards, won't that be extremely dizzy? :) So what are the immediate (strange) properties brought forward by median of 6 days of orbit period? [1] http://www.space.com/images/i/000/062/962/original…

Earth has a rotation period of 1 day (around itself). When stargazing a 1 day rotation period would be the same as 1 day orbital period whilst being tidally locked (which seem to be the case for these planets)

I don't think anyone is getting dizzy down here so I would assume it would be the same there? or have I missed something?

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

#672

Post by alex_duf »

bbarn wrote: post #587
echelon wrote: post #575

I imagine any intelligent life that evolves on a system with so many planets in such close proximity--many within the habitable zone, and each perhaps with atmospheres and organics--will have a much easier time than we do of pushing forward to becoming a multi-planetary species. We lucked out with Earth being as hospitable and resource rich as it is, but we're stuck in a deep gravity well with not much in our solar s…

..and what problems we don't have they might have! Planets too close, disrupting each other's ecosystems. The usable ice being distributed amongst several planets when the system was formed instead of a single one.. there's no end to catastrophic possibilities. This is why I still love sci-fi. Anything you can think of, put it on paper, and it could make for a great story.

Not to mention the whole "us" and "them" separation that would eventually arise the same way we have with our arbitrary borders.

Hmm, wait we were talking about intelligent species, never-mind.

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

#673

Post by [deleted] »

mjevans wrote: post #450
vkou wrote: post #288

Earlier quoted context omitted.

Voyager spent most of the first season looking for deuterium, so that they could keep the ship moving forward. Presumably, at some point around episode ~15, someone in either engineering, or the writing team realized that it is the third most abundant element in the universe.

It doesn't just have to be common, it has to be worth harvesting. It could be that it took them this long to locate and get to such a supply, or that they had to repair / construct equipment that normally wouldn't be expected to be used.

[deleted]

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

#674

Post by kuschku »

npunt wrote: post #594
Dylan16807 wrote: post #534

Earlier quoted context omitted.

> Still, assuming light speed travel, Firefly's inhabited planets are still a heck of a lot closer, since the crew doesn't seem to noticeably age between the half dozen or so star systems that they visit, and don't appear to have any kind of tech to reversibly[1] halt their metabolisms. Closer than what? This system is significantly smaller than Firefly's. Or do you mean closer than this system is to Earth? Don't wor…

I never realized Firefly was in a super-system. Gravity would rip that thing apart in an instant.

They actually did numeric simulations of that system, and it seems to be stable for several millenia at least (their entire simulation time).

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

#675

Post by jacobush »

rocqua wrote: post #652
blueprint wrote: post #338

Earlier quoted context omitted.

Yeah I'm to be honest just trying to awaken people to the priority being that we need to establish a self-sufficient colony somewhere other than Earth.

Honestly, as long as humans stay stuck to earth, losing all humanity on earth won't hurt anyone. As long as the extinction is instant. If we have colonies, those colonies need to suffer through the knowledge that we lost earth. Establishing colonies is only imperative if the continuation of the human race is. I'd argue that humans have value only due to other humans. There is nothing inherently valuable about human l…

"There is nothing inherently valuable about human life from a non-human perspective."

How would you know?

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

#676

Post by jp555 »

echelon wrote: post #575

I imagine any intelligent life that evolves on a system with so many planets in such close proximity--many within the habitable zone, and each perhaps with atmospheres and organics--will have a much easier time than we do of pushing forward to becoming a multi-planetary species. We lucked out with Earth being as hospitable and resource rich as it is, but we're stuck in a deep gravity well with not much in our solar s…

Although they'll have a lot more intense x-ray and UV radiation to deal with. Surviving for long enough from under ice or an ocean might be harder than getting out of our gravity well.

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

#677

Post by pharke »

bborud wrote: post #405
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…

So this means all the planets are all a volcanic mess because of the tidal forces?

Perhaps some of them, especially the innermost. Considering the orbital periods and resonance it seems like this system might be similar to the Jovian or Saturnian systems.

The planets may be tidally locked but there is also a chance they could have a slow rotation similar to Mercury. That planet has also shown us that a magnetic field is possible without a fast rotation so there's a chance of these exoplanets having one as well.

Tidal forces can be a boon to planets with synchronous rotation since they provide an additional source of heating for the side of the planet that faces away from the star. If there is liquid water or a thick atmosphere they may also drive tidal and weather patterns that could help circulate heat from the warm side to the cold side.

Geological activity also 'stirs the pot' when it comes to precursors for life. All this extra energy in the system could mean that even TRAPPIST-1g (outside the habitable zone) might have an atmosphere and oceans.

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

#678

Post by mememachine »

settsu wrote: post #459
RileyJames wrote: post #388

Earlier quoted context omitted.

It looks like the James Webb cost $8.7B to launch. The Hubble $4.7B at launch and $10B through till 2010. So it seems cost is the limiting factor. Replicas might be cheaper, but they wouldn't be kickstarter cheap.

In an attempt to avoid the appearance of politicking, I'd offer that this is not as significant a sum as it may seem initially, viewed in relative terms to... other governmental expenditures.

You should remember that youre not the only one trying to take and spend tax money.

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

#679

Post by Raphmedia »

callumprentice wrote: post #607

A few months ago, I made a simple WebGL app to compare the sizes of our sun and the planets for my 5 year old daughter who was curious. I updated it today to include the TRAPPIST system and see how it compares to our own solar system. http://callumprentice.github.io/apps/celestial_bodies/index....

I love it! The fact that you made it for your daughter is even better!

Comparing our sun with Trappist's star is really interesting. Try to compare it with Jupiter. They are almost exactly the same.

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

#680

Post by nkrisc »

jacobush wrote: post #675
rocqua wrote: post #652

Earlier quoted context omitted.

Honestly, as long as humans stay stuck to earth, losing all humanity on earth won't hurt anyone. As long as the extinction is instant. If we have colonies, those colonies need to suffer through the knowledge that we lost earth. Establishing colonies is only imperative if the continuation of the human race is. I'd argue that humans have value only due to other humans. There is nothing inherently valuable about human l…

"There is nothing inherently valuable about human life from a non-human perspective." How would you know?

It's a perfectly reasonable assumption until there's some evidence there is. Given the vastness and scale of the universe, it seems quite likely that our disappearance would never be noticed.
Post reply on HN