Seven Earth-Sized Planets

[Cray]

Trappist-1. I wonder if the locals have any good beer.
http://www.bbc.com/news/science-environment-39034050

[radtech497]

If they do, it'll only be available on Planet "e" (the only planet in the system where water could exist as a liquid on the surface in significant quantities over geological periods). However, the system is a bit young to expect anything more evolved than the yeast someone else could use in the brewing process.

Radtech497

[stevebowers]

This page has very nice NASA images of what they think the planets may look like.
http://www.jpl.nasa.gov/spaceimages/deta...d=PIA21422

This artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.

The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial, according to research published in 2017 in the journal Nature. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it.

They are likely all tidally locked, meaning the same face of the planet is always pointed at the star, as the same side of our moon is always pointed at Earth. This creates a perpetual night side and perpetual day side on each planet.

TRAPPIST-1b and c receive the most light from the star and would be the warmest. TRAPPIST-1e, f and g all orbit in the habitable zone, the area where liquid water is most likely to be detected. But any of the planets could potentially harbor liquid water, depending on their compositions.

In the imagined planets shown here, TRAPPIST-1b is shown as a larger analogue to Jupiter's moon Io. TRAPPIST-1d is depicted with a narrow band of water near the terminator, the divide between a hot, dry day and an ice-covered night side. TRAPPIST-1e and TRAPPIST-1f are both shown covered in water, but with progressively larger ice caps on the night side. TRAPPIST-1g is portrayed with an atmosphere like Neptune's, although it is still a rocky world. TRAPPIST-1h, the farthest from the star, would be the coldest. It is portrayed here as an icy world, similar to Jupiter's moon Europa, but the least is known about it.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech, also in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.

For more information about the Spitzer mission, visit http://www.nasa.gov/spitzer and http://spitzer.caltech.edu.

[stevebowers]

I particularly like the images of TRAPPIST-1d and TRAPPIST-1f. A dry, hot Hesperian world and an eyeball-Earth. The one image I disagree with is TRAPPIST-1g; that world is shown as a mini-Neptune, but there is a good chance that TRAPPIST-1g is the most Earth-like of the lot. Instead of having a dense atmosphere, it may have lost a significant amount due to flaring from the star; it should also be heated tidally by the proximity of so many other planets. So it could be warm, with a relatively thin atmosphere, and could be rotating due to spin-resonance. Probably not very Earth-like, but it should be terraformable using OA tech. (most of the others could be terraformed too, but with increasing levels of difficulty.)

[Cray]

These planets do fit the layout of another system...

[stevebowers]

Oh, KSP. Of course.

[four]

Theoretically speaking, I suppose all seven of these planets could be terraformed? Some of them will obviously be easier to terraform than others, though.

For the inner three planets, you might be able to cover the hot sun-facing sides in solar panels and then build settlements on the more hospitable dark side.

(I'm talking about human settlements here; obviously vec/toulh settlements would have different temperature requirements.)

[stevebowers]

For the inner three planets, you might be able to cover the hot sun-facing sides in solar panels and then build settlements on the more hospitable dark side.

That is a very good idea. The colony on Sisyphos uses a similar strategy.
The innermost world, TRAPPIST-1b, would be a challenging environment; heated by the star and by tidal flexing, it would probably be covered in volcanoes, but this would mean a lot of geological processes are occuring there, mixing and sorting out its constituent elements. This world would like a giant chemical laboratory, and could be a good source of minerals and resources.

[stevebowers]

Here's Andrew LePage on the 'habitability' of these worlds.
http://www.centauri-dreams.org/?p=37225
As usual, Andrew dispels some (newly-minted) myths about these exoplanets; the best candidates aren't d,e and f, but rather e,f, and g.
Edit/Delete Message