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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

#231

Post by ianmcgowan »

rubicon33 wrote: post #9

I was reading up about earth alternatives recently, and upon realizing the distance was always going to limit us, no matter how perfect the planet, I realized we need to travel at the speed of light. I think our "best shot" at that right now, is to digitize humans. If we could store consciousness in binary, we could then transmit it at the speed of light (like we do with data every day!). You'd need a receiver on the…

I hate to always post links to Greg Egan, but he's sort of the XKCD of SciFi - if there's an out there concept, he's usually written a book about it. In this case Incandescence:

https://www.amazon.com/dp/B0070YQOHW

Top review has the best summary: "Egan's story is set in the galactic core, inhabited by a race known as the Aloof, because they seem almost indifferent to any attempts at communication from the Amalgam, the loose network of civilizations that inhabit the rest of the galaxy. However, they do allow thrill-seeking members of the Amalgam to enter their transportation network, digitizing themselves for transmission at the speed of light across the galactic core, instead of the long way around it."

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

#232

Post by sampo »

hughes wrote: post #122
stupidcar wrote: post #87

Earlier quoted context omitted.

Well, it's "at least" 500m, but is probably much more[1]: "Determining the ages of such small stars is difficult because they evolve so slowly over their lifetimes of trillions of years but it is estimated to be in excess of a half a billion years and is probably much more." And abiogenesis occurred on Earth within about 500m years of the Earth's formation, so life can clearly arise pretty quickly. It's complex, mult…

> trillions of years This is off by several orders of magnitude. Like estimating the age of your neighbor to be somewhere around 400,000 years old.

That is not talking about the age, but about the possible life span, into the future.

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

#233

Post by pshposh »

sigmaprimus wrote: post #146
pvg wrote: post #102

Earlier quoted context omitted.

18k years is a very long time, though. There is a project looking at the feasibility of getting very small probes somewhere 10 times closer in perhaps decades rather than millennia: https://www.nytimes.com/2016/04/13/science/alpha-centauri-br...

That is exactly what I meant, thank you for the link. I defiantly would support projects like that.

I suspect you meant definitely and not defiantly.

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

#234

Post by ryandrake »

JumpCrisscross wrote: post #86
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)

> about...2,000 Saturn V rockets Or about 670 BFRs [1]. It would take 6 cycles of tripling size and/or performance to get a single system with enough thrust to meet your 7/42 year schedule. The Saturn V first flew in 1967 [1]; SpaceX plans to launch its Interplanetary Transport System (ITS) in 2022 or 2024 [2]. That's an expected 60 years to triple performance. [1] http://waitbutwhy.com/2016/09/spacexs-big-fking-rock…

To put that 60 years into perspective: It was 66 years between the first powered airplane flight and landing people on the moon.

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

#235

Post by panic »

noselasd wrote: post #229
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)

> 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 is assuming constant energy consumption to sustain 1g, but unfortunately that's not the case, the closer you get to the speed of light, the more energy you'd need to sustain 1g, and this becomes unrealistic long before you are anywhere close to the…

Your speed doesn't affect the laws of physics you experience.

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

#236

Post by cgriswald »

jonshariat wrote: post #177

This news is very interesting but how is this different than any of the recent planet discoveries? Anyone mind explaining the significance of this discovery over the others?

1. There are a lot of them (seven). 2. They are all Earth sized. 3. There are a lot of them in the habitable zone (three). 4. Even those not in the habitable zone could contain liquid water under certain circumstances. 5. This star is insanely close-by (39 ly).

Basically, if you're looking for a second Earth, this is an incredible gift. Even if we don't find a second Earth among these seven planets, they could tell us a lot about the likelihood of life around red dwarf stars, which is significant, because the vast majority of stars are red dwarfs. That's in addition to the information they can probably provide on planet formation and makeup.

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

#237

Post by eanzenberg »

flexie wrote: post #194
_lbaq wrote: post #131

Earlier quoted context omitted.

Very likely, since this happens between Mars and Earth: https://en.wikipedia.org/wiki/Martian_meteorite

Fascinating! Would vira or bacteria beable to survive travelling from Earth to Mars in or on a rock or vice versa?

Possible, but cross-section for collision is way way smaller in the Earth-Mars system. Cross-section goes as r^-2 so the closer the bodies, the 'way better' it is.

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

#238

Post by logfromblammo »

idbehold wrote: post #209
pshposh wrote: post #155

Earlier quoted context omitted.

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?"

That's not depressing. It gives us a moral imperative to transplant Earth-origin life onto every somewhat concentrated mass that we can reach.

Then we can wait a few billion years, and the universe will likely have generated a superior successor species which can then re-seed over everything we had previously tilled, and then some.

And they'll all be rubber-forehead aliens to one another, because they'll be billionth cousins, a few million times removed.

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

#239

Post by mstade »

JumpCrisscross wrote: post #34
ionwake wrote: post #17

Earlier quoted context omitted.

Out of interest , although dimmer, are there any potential hazards simply due to the proximity of a dim star?

> 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…

Fascinating! Also – off topic, but – this description reminded me of Twinsun[1], the planet in the game Little Big Adventure. It remains one of my fondest game memories of that era, despite all its weird bugs. I've thought about finding a copy and playing it again at some point, but I fear it might spoil my good memories of it..

[1]: http://lba.wikia.com/wiki/Twinsun

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

#240

Post by [deleted] »

JumpCrisscross wrote: post #34
ionwake wrote: post #17

Earlier quoted context omitted.

Out of interest , although dimmer, are there any potential hazards simply due to the proximity of a dim star?

> 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…

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