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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

#201

Post by Keyframe »

bcaulfield wrote: post #10
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, basically, this is cooler than just about any world that's been depicted in sci-fi.

Uh, Mongo when it flew by Earth?

edit: Mongo from Flash Gordon

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

#203

Post by semaphoreP »

blueprint wrote: post #72
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.

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. :\

A Russian billionaire is trying: https://breakthroughinitiatives.org/Initiative/3

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

#204

Post by chris_va »

wallace_f wrote: post #170
delecti wrote: post #157

Earlier quoted context omitted.

Just going that fast isn't really risky at all (assuming you don't hit anything, which isn't actually a safe assumption). The tough part is making something capable of a constant 1g of acceleration for a 7 year trip. Most of the craft we make only accelerate for the first small percent of a trip. We can do accelerations that high, but not for very long, and we can't even manage acceleration for such a long duration e…

My layman's reading of physics-for-layman books has taught me that if we were to travel at the speed of light, we'd convert into energy. However, I'm not so sure about 99.999999% the speed of light. That's really OK, as far as we know?

You are technically travelling at 99.99999% of the speed of light right now, relative to something.

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

#205

Post by ilamont »

noobermin wrote: post #121
chrisabrams wrote: post #36

Earlier quoted context omitted.

I was essentially thinking the same thing. I wonder if an elevator could be built between all of them?

One of the callers (a biologist, so not a crackpot) on TV suggested that given how close the planets were, he wondered if it were possible for there to be cross contamination between the planets given how close they are to each other. He referred to them being part of the same "ecosystem." I'm not sure how feasible that is as a non-astrobiologist, but it is an interesting idea.

Gene Wolfe mined this idea for some of his science fiction works, except it was alien life making the jump ... Fifth Head of Cerberus & Blue's Waters/Green's Jungles.

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

#206

Post by dragonwriter »

ionwake wrote: post #165
gus_massa wrote: post #94

Earlier quoted context omitted.

> Not according to public research on theoretical designs that have been about for decades. Which ones? Do you have a link? The only one I remember is https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... but it's more a general idea that a detailed blueprint that only need some money to get built.

Thats the one I read. It sounds awesome. Srsly give me 5% of the GDP of the US and I'll put a monkey on Trappist within 5 years. Monkey time. *Im not being serious, I have no idea how much it would cost or if it would even work.

Project Orion doesn't get you anywhere close to 1G constant acceleration to turnover and constant deceleration the rest of the way; a fairly high performance Orion concept for interstellar use did have 1G acceleration, but only for 10 days on each end of a 133 year trip to Alpha Centauri -- and needed 300,000 nuclear bombs with 1 megaton yield each as fuel.

> Srsly give me 5% of the GDP of the US and I'll put a monkey on Trappist within 5 years.

No, you won't. First, you won't design and build and launch a ship that will ever get to TRAPPIST-1 within 5 years at that (or any) price, and second TRAPPIST-1 is close to 40 light-years away, so even if you had a ship built and ready to launch today, you aren't getting anything there within 5 years.

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

#207

Post by cstejerean »

noobermin wrote: post #88
JumpCrisscross wrote: post #34

Earlier quoted context omitted.

> are there...hazards simply due to the proximity of a dim star Tidal locking [1]. Similar to how our moon shines at us ass first all the time, the planets around TRAPIST-1 would be expected to have one face locked to their star. Instead of an equatorial belt bookended with loops of temperate zones, as we have on Earth, we should expect, climatically, an "equatorial" face and a "polar" face separated by a tropic-to-t…

Of course, #askNasa didn't win me a question, but could any astrobiologists comment on this question: Tidal locking means the planets would always have a side facing the star, leading to very different thermodynamics in terms of climate and weather on the planet, not to mention radiation. Doesn't that very much hurt the chances for life on those planets?

Apparently what would hurt the chance of life in a tidally locked planet the most is that due to being tidally locked the planet would have a reduced magnetic field to protect the atmosphere, and therefore there is a good chance that the planet would lose it's atmosphere over time.

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

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

#208

Post by dragonwriter »

ionwake wrote: post #160
twoodfin wrote: post #77

Earlier quoted context omitted.

It's not money, it's the basic rocket equation: Newtonian acceleration requires fuel and the mass of fuel makes acceleration more costly. Relativity makes things even worse.

See comment above yours, does your point still apply?

Absolutely.

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

#209

Post by idbehold »

pshposh wrote: post #155
h4nkoslo wrote: post #41

Uh oh. The "great filter" hypothesis is essentially that the rarity of intelligent life has to be explained by some parameter of the Drake equation, and that whatever the "small" parameter is is either in our past or in our future. If the "great filter" is the rarity of habitable worlds, then clearly we don't need to fear it, since we already found one. But if habitable worlds aren't rare, then it's more likely it li…

But what if we are the first and no filter exists at all?

That's almost equally depressing. "Really, we're the best the universe has to offer?"

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

#210

Post by biot »

JumpCrisscross wrote: post #92
dwaltrip wrote: post #82

Earlier quoted context omitted.

In the Q&A session they said it's difficult to constrain the age of the long-lived ultraviolet dwarf stars once they finish the active early phase, as their lifecycle progresses so slowly. They live for more than a trillion years, compared to stars like our sun which are larger and burn through their fuel in less than 10 billion years. It's somewhat counterintuitive, but the bigger a star is, the faster it uses up it…

> it's difficult to constrain the life of the long-lived ultraviolet dwarf stars What's the upper bound on their estimate for TRAPIST-1's age?

The upper bound is the age of the universe.
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