Oolite Bulletins

https://www.nasa.gov/press-release/nasa ... ets-around

NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other.

That's a crowded system! An ultra-cool dwarf, eh?

Cody wrote:

An ultra-cool dwarf, eh?

That could mean the system is very, very old, compared to our own … it could also mean that the planets in the habitable zone are tidally locked.

<nods>

read this earlier today. they highlight Trappist-1 d with a 3d model. you would be able to see 2 or 3 of the other planets at night!
only problem i see is the year is only 18.2 days!! thats some speedy planet.

the problem for possible life is that theyre most likely tidally locked which can causes extreme temperatures and so extreme wind.

i read that as well, but didnt they recently find that Mercury is not tidally locked? so there is a chance these are not.

spud42 wrote:

i read that as well, but didnt they recently find that Mercury is not tidally locked? so there is a chance these are not.

True, but Mercury is six times farther from the sun than the outermost planet is from Trappist-1. Then again, Trappist-1 is a lot less dense than our sun. The only way we'll know for sure is if we go there and find out!

In the meantime, the Trappist-1 system has a website of its own:
http://www.trappist.one

More news on this system at El Reg.

It might be possible to warm one of the snowballs up a bit, with one of these - a prototype engine using the Leidenfrost effect on frozen CO2 to power an engine:

https://www.eng.ed.ac.uk/about/news/201 ... -life-mars

Energy from dry ice? Interesting!

Boffins now reckon they're probably a bunch of water worlds.

And when they say "water worlds" they mean literal globes of water with a solid core. Earth's proportion of water is about what you'd get if you picked a pool ball out of a bucket of water (a couple of miles depth on a 4000-mile radius is almost literally just a film of water, in planetary terms).

<nods> Yep, not a lot of water on planet Earth.

Indeed. Trouble with all that water is you need some dissolved solids as well to make bio-compounds out of, I think - you can't get very far with just water and a reducing atmosphere. And possibly some shallows for the reactions to occur in.