7 earth size planets orbiting same star!!

You could fly out of spacedock really slow with it at one quarter... backwards if necessary.

 

Only thing I don't see humanity getting a spacedock, or any other nice thing for a very, very long time.

 

ISS was going to be a spacedock--when it was called Space Station Freedom

https://en.wikipedia.org/wiki/Space_Station_Freedom
http://www.aerospaceprojectsreview.com/blog/?p=886
http://www.astronautix.com/graphics/s/ss84diag.gif

Now, if SLS to LEO becomes more of a thing--just maybe--we could see ISS get bigger. Probably not--but dumping it in the ocean is a waste.

 

It's more then a waste it's criminal. Ah. Why not sell the ISS to the UAE and they can use it as a hub to start more stuff?

 

I think Bigelow may have plans for it. I want the truss saved if nothing else.

 

First Images Of Trappist - 1 Show Dips In The Light Curve Suggesting A Planet Transiting Trappist - 1
http://www.ibtimes.com/nasas-kepler...ed-dwarf-show-dips-stars-light-output-2506947

If the planets are packed together like it thought then the discovery could lead to an understanding of what is taking place at KIC 8462.

 

I'd like to see the core of it repurposed as an Earth-Moon Lagrange Point station when SpaceX and NASA have deep-space manned capability. It would need an additional radiation shelter, of course.

 

It looks like SLS will be sent to ISS. I want more truss segments and it turned into a solar electric tug, so it will no longer be in LEO. A shame to drop that into the ocean.

 

Or else Mintaka would be a sort of "landmark star", a star nearby that's easy to see because it's bright.

I've found this paper on TRAPPIST-1: eso1706a.pdf Table 1 (PDF page 8) has lots of details, like equilibrium temperatures. Comparing to the Solar System how much light each planet gets, I find:

• b: Somewhat farther than Mercury
• c: A bit closer than Venus
• d: A bit closer than the Earth
• e: Halfway between the Earth and Mars
• f: A bit farther than Mars
• g: A bit closer than the inner edge of the main asteroid belt
• h: In the main asteroid belt, at Ceres

The paper mentions mass estimates from Transit Timing Variations (TTV's). These are from perturbations of the planets on each other. They are in some orbit resonances, and that amplifies some of the longer-period perturbations. However, these TTV masses are very imprecise, with error bars almost as big as the masses themselves.

There is an exception: planet f. It has 0.68 +- 0.18 Earth masses. With a radius of 1.045 +- 0.038 Earth radii, it has a density of 3.3 +- 0.9 g/cm^3, low enough to be consistent with having a huge ocean. If water is about 25% by mass and the remaining 75% mostly rock, then the ocean would have a depth of around 1000 km.

At its distance, the ocean would likely be frozen over, with a possible exception near the substellar point, the point where the Sun is directly overhead. But the planet's rocky material likely contains long-lived radioisotopes, so that part could generate enough heat to keep much of the ocean melted. I say "much" because below a few hundred km, it's likely to be frozen as another sort of ice, one called Ice VII. Geological activity may well create some "chimneys" in this ice, however.

 

They are looking for names for them. I suggest naming one of them Vulcan (just a thought)

 

Have Great Name Ideas for the TRAPPIST-1 Planets? NASA Wants to Hear Them At Twitter hashtag #7NamesFor7NewPlanets

Names like Harry-Potter-themed names, Star-Wars-themed names, names of great composers, names of notable astronauts, ...

 

Seven deadly sins, seven dwarfs, seven colours of the rainbow, seven brides, seven brothers, seven things I hate about you by Miley Cyrus...

 

Sure it will. Just as soon as the USS Gerald Ford completes a combat patrol in Lake Michigan.

 

Now now...

In terms of names...


Ghroth
Pnidleethon.
Yamil
Zacra
Yuzh
Carcosa
Xiurhn

 

[1703.01424] Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
[1703.04166] A terrestrial-sized exoplanet at the snow line of TRAPPIST-1
[1704.04290] Updated Masses for the TRAPPIST-1 Planets
And, of course TRAPPIST-1 - Wikipedia

We now have more than one observation of a transit by the outermost known planet, h. This pins down its orbit period, and this has an odd consequence. All several of the planets are in a resonance chain:
8:5, 5:3, 3:2, 3:2, 4:3, 3:2

Thus, for every 8 orbits b makes, c makes 5 orbits, d makes 3 orbits, and e makes 2 orbits. These resonances combined with the planets' gravity make the planets alternately speed up and slow down relative to each other, over a timescale of several months. This causes Transit Timing Variations (TTV's) that have been observed, and these TTV's have been used to come up with mass estimates for these planets.

Those estimates still have big error bars on them, but it's enough to get estimates of their likely composition. That is done with the help of theoretical models of all-iron, all-rock, all-water, and all-hydrogen-helium planets. One has to take into account the compressibility of these materials, since for Earth-mass or more, the planets will have noticeable interior compression. For the Earth, one can measure how much compression by studying earthquake waves. One finds that the Earth's mantle starts at a density of 3.4 g/cm^3 and goes up to about 5.5 g/cm^3. The core is largely iron, with an uncompressed density of 7.8 g/cm^3. It starts at about 10 g/cm^3 and ends at 13 g/cm^3 in the Earth's center.

 

The results for the TRAPPIST-1 planets:

Planets e, f, g, and h are well in the mostly-water range, b is also in that range, but closer to rock, d straddles rock, while c is between rock and iron, just like the Earth and Venus.

So at least five of these seven planets are likely to be water worlds or ocean planets, with oceans much deeper than the Earth's oceans. For the farther ones, the oceans are likely to be iced over, though there may be a spot of liquid water where the TRAPPIST-1 star is almost directly overhead. Thus making such planets "eyeball planets".


As to names, people have thought of a large variety of them:
#7NamesFor7NewPlanets hashtag on Twitter
Have Great Name Ideas for the TRAPPIST-1 Planets? NASA Wants to Hear Them
Twitter users suggest names for Trappist-1 's new planets | Daily Mail Online

My proposal:
Star: (George) Adamski
Planets: Orthon, Kalna, Ilmuth, Firkon, Ramu, Zuhl, Desmond (Leslie)

 

I think it'll happen as soon as we develop superstrong materials. If we can build a space elevator, the cost of shipping things into orbit will be nothing compared to what it is now.

 

I love that idea. But from the ground what would it look like? Would it be like some kind of shaft that reaches into the sky without end from our POV?

They had one in an episode of Voyager I think.

 

Yeah it would look like a building that disappears into a point in the sky.

I'm convinced that this will be the next great leap forward. Super-strong materials like carbon nanotubes already exist but they can't be mass manufactured. It was the same deal with aluminium back in the day. Once we figured out a way to produce it in mass quantities fairly cheaply there was an aluminum revolution. If we can manufacture something to build a space elevator with, we can go from having tiny ships with giant fuel tanks to having massive ships that are assembled in orbit.

 

Earlier this year, this paper was added to the Arxiv preprint archive: [1802.01377] The nature of the TRAPPIST-1 exoplanets For a nontechnical summary, see New Clues to TRAPPIST-1 Planet Compositions, Atmospheres - NASA Spitzer Space Telescope and the video in Not So Strange New Worlds - NASA Spitzer Space Telescope. Imagining the Planets of TRAPPIST-1 - NASA Spitzer Space Telescope has some artist's conceptions.

The planets' masses were determined with TTV's, as before, with the numbers now being much better. Here are their average densities (g/cm^3):

b: 4.00, c: 4.87, d: 3.40, e: 5.64, f: 4.50, g: 4.18, h: 3.96

The inner Solar System: Mercury 5.427, Venus: 5.243, Earth: 5.514, Moon: 3.340, Mars: 3.933

I estimated how much water is on these planets' surfaces by using a composition estimate: these planets have rock and iron, but a somewhat smaller fraction than the Earth does. That gives us these mass fractions of water:

b: 0.05, c: 0.02, d: 0.05, e: ~0, f: 0.02, g: 0.04, h: 0.03

Those numbers don't look like much, but the Earth has 0.00023 for its oceans. Those oceans' average depth is 3.7 km, and averaged over all the planet's surface, 2.6 km. Here are my estimated average depths, also in km:

b: 400, c: 200, d: 250, e: ~0, f: 250, g: 400, h: 150 (error bars: ~100 km)