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7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/22/2017 6:18 PM

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.

The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.

This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.

The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.

Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.

Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.

"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds."

more ...

https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around

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#1

Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 6:20 PM

How long will it take us to get there?

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#3
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 7:11 PM

It all depends on the air-speed velocity of a swallow.

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#8
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 7:27 AM

African Swallows?

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#4
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 7:24 PM

At 18000 mph, about 1 1/2 million years.

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#5
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 7:56 PM

Well we had better get going then.

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#30
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 8:08 PM

There is talk about sending people to Mars, which is 100 times as far as the moon, when we haven't sent anyone to the moon for almost half a century. I am amused that now there is now talk about colonizing these planets which are 1.5 million times as far away as Mars!

Could new Earth-like exoplanets be ripe for colonization?

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#31
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 8:57 PM

Who said we've got high in the sky apple pie hopes?

It was one of those day's for laughing at newscasters intelligent commentary.

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#6
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 8:30 PM

This place is cool....

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#33
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/24/2017 7:23 AM

Solar eagle, since you are so good with images, can you present a picture of the universe showing where we are and where they are, then we can get a perspective of how far or how close that group of planets is ?

This may help us to answer your question.

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#37
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/24/2017 1:33 PM

The Milky way is about one hundred thousand light-years diameter and on average about one thousand light-years thick with a slightly lumpy bit in the middle. So imagine a thick cardboard disk ten inches across and one tenth of an inch thick. Nearly all the stars we know a lot about are closer than half the thickness of the disk away, and, at 40 light years this (Trappist 1) is one twenty fifth or 4% of the thickness of the disk away.

Should be able to get a local bus really.

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#38
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/24/2017 3:44 PM

http://www.fairline.com/en/

The galaxy as explained by Eric Idle. Enjoy.

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#40
In reply to #37

Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/24/2017 8:41 PM

Randall: That's a very good explanation. Have you ever thought about pursuing a career in education ?

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#43
In reply to #33

Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/26/2017 12:20 PM

If you could walk at light speed......

If you were to start out on a journey of walking for 40 years, non-stop, how far would you go in 8 minutes? That would be the equivalent of walking to the Sun....Mars ranges from 4 to as much as 20 minutes away....Jupiter is between 35 and 52 minutes away....Pluto, on the edge of the Solar System, is 5 hrs and 45 minutes away...about 4 years of constant walking brings you to the nearest star, Alpha Centauri....Walking at 3 mph you would have circled the globe over 4 times and traveled 105,408 miles....However the speed of light is 671 million mph in reality, not 3....

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#44
In reply to #33

Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/26/2017 1:35 PM

TRAPPIST-1's galactic coordinates are 69.7127° -56.6446°, 39.5 ly, that is, the system is 69.7127° north of the galactic plane and 56.6446° to the right ('east') of the galactic centre, and 39.5 light-years distant.

As the Sun itself is about 57 light-years above the galactic plane, TRAPPIST-1 is 57 + 39.5 sin 69.7127°, or about 94 light years above the galactic plane and so well inside the 1000-light-year thickness of the galaxy's disk at this location.

This view of Galactic Coordinate System is a bit clearer than Wikipedia's. Where the example shows a positive galactic longitude, TRAPPIST-1's negative longitude would be to the right of the galactic centre, ie, at longitude 303.3554°

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#45
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/26/2017 10:07 PM

Erratum:

Simbad's 2MASS catalogue entry lists J23062928-0502285 (TRAPPIST-1)'s galactic coordinates in lon,lat order but doesn't explicitly state the coordinate order, leaving the reader to guess. I assumed (my bad) that it was cited in lat,lon order, but no, it is the other way around.

Also the website's description popup for that item is incorrect, stating that the coordinates are given as Right Ascension (hms) and Declination (deg). No, they're galactic, not celestial, coordinates, and so both coordinates are in degrees. Sigh).

Because of the coordinate reversal, TRAPPIST-1 is 69.7127 degrees left of the galactic centre, and 56.6446 degrees below ('south') of the galactic equator/plane. As the Sun is 57 light-years above the galactic plane, TRAPPIST-1 is 57 + 39.5 sin(-56.6446) = ~24 light-years above the galactic plane - nearly dead-centre in the plane of the Milky Way.

The radius of the red disk is 39.5 cos(-56.6446) = ~22 light-years (not to galactic scale, obviously, but scaled to show the general direction. Were it to scale, it would be less than a pixel across)

Sorry about the confusion, Tony.

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#2

Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/22/2017 7:10 PM

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius.

If they're in the constellation Aquarius, they've got to have water...

https://en.wikipedia.org/wiki/Aquarius_(constellation)

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#7
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 2:36 AM

I'd only go there if they learned how to transform water into one of the more valuable things like beer or interstellar coffee.

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#20
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 1:09 PM

The TRAPPIST* (a backronym) telescope is a Belgian optical robotic telescope, situated high in the Chilean mountains at ESO's La Silla Observatory, which came online in 2010. It is named in homage to the Trappist religious order, who are known for brewing their Trappist beer. Westvleteren is a brewery founded in 1838 at the Trappist Abbey of Saint Sixtus in Vleteren, Belgium.

-----

* TRAnsiting Planets and PlanetesImals Small Telescope

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#22
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 2:30 PM

Probably closer....

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#24
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/23/2017 4:23 PM

or interstellar coffee.

I am sure Starbucks is on the way.

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#35
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Re: 7 Earth-Size, Habitable-Zone Planets Found around a Single Star

02/24/2017 9:46 AM

You are correct, it is dehydrated water, in a packet. They are just not sure what to add.

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#9

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:12 AM

Here are some details on the Trappist-1 System NASA spoke about yesterday. The star in the Trappist-1 System is an Ultra-Cool Dwarf Star (cool as in cold, not cool as in ). The star has 8% of the Mass and 11% of the radius of the Sun. It's Luminosity is 0.05% that of the Sun. For that reason the habitable zone for this star is very, very close to the star. Also, due to its low effective temperature, the star appears red. Here are some cool pics showing what I just said above:

Size and Color Difference Between the Sun and Trappist-1's Ultra-Cool Dwarf Star

A little perspective on the small interplanetary distances in the Trappist-1's system

How the Trappist-1 System distances compare to our Solar System Distances. To see image below more clearly, go here

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#10
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:24 AM
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#25
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 5:06 PM

Any estimated surface temperatures on any of the seven newly discovered planets yet?...

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#26
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 5:32 PM

Any estimated surface temperatures on any of the seven newly discovered planets yet?..

Not yet, mainly because atmospheres can make a really big difference. For instance the surface of Venus is around 850 Fahrenheit where, as you know, on Earth we are more around 50 Fahrenheit (with some variation). I looked it up and Venus is just outside our solar systems habitable zone (too close to the Sun), but clearly most of the temperature difference between Earths and Venus' Surface Temps are from the difference in the density of their atmospheres.

When the James Webb telescope is launched in 2018, they might be able to better determine surface temperatures since it should be able to figure out atmosphere composition and density.

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#27
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 5:43 PM

...Or what the atmosphere and composition was 40 years ago.

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#29
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:04 PM

True! At least till we get a stargate built!

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#46
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/27/2017 1:41 PM

The idea was an attempt to ask if any of the seven planets had a similar (solar exposure) to that which we have here on Earth, in order to make a more direct comparison about the possibility of extraterrestrial life similar to us humans (i.e.: cooler than Venus and warmer than Mars) ...

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#11

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:32 AM

What happened to (a) then?

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#14
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:59 AM

According to IAU convention, the letter indicates the order of the planet's discovery around its host star. The first exoplanet discovered in another solar system is designated b; the second, c; the third d; and so on. The letter does not indicate the planet’s orbital placement around its host star, so Exoplanet-c can be closer to, or farther away from, the star that it co-orbits with Exoplanet-b.

The lowercase lettering style is drawn from the IAU-established rules for naming binary and multiple star systems. A primary star, which is brighter and typically bigger than its secondary or tertiary companion stars, is designated by a capitalised A. Its companions are labelled B and C, and so on. Sirius, the brightest star in the sky, demonstrates this nomenclature. Actually a double star, the bright star we see in Canis Major is Sirius A, and its dim companion is Sirius B. The first exoplanet tentatively identified around the second brightest star in the triple star system, Alpha Centauri, is accordingly called Alpha Centauri Bb. If an exoplanet orbits both of the stars in a binary system, its name can be, for example, Kepler-34(AB) b.

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#15
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 9:39 AM

Got it! Thanks.

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#12

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:49 AM

I'd love to know more about the tidal effects on these planets given that there are so many of them and they are so close together. The difference in tidal forces from when all of these planets are in alignment and when they are not must be meaningful (I'm guessing, I haven't calculated).

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#36
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/24/2017 10:05 AM

Wobbly day lengths, one suspects?

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#13

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 8:54 AM

After the announcement, scientists associated with Trappist-1 held a AMA (ask me anything) on Reddit. For those of you not familiar with AMAs, it's basically an opportunity for Redditors to ask the scientists questions in a forum thread and the scientists respond. Pretty cool read. If you're interested, here's the link:

https://www.reddit.com/r/IAmA/comments/5vkoyd/were_nasa_scientists_exoplanet_experts_ask_us/

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#16

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 11:50 AM

The Trappist-1 solar system is certainly worthy of further astronomic study, even if only for the fact that no Jupiter- or Saturn-style planets have formed there (yet?)...

A lot could have happened in the 40-million, or so, light-years it took for the images we now have of Trappist-1 to become visible to us, here on Earth, now...

In the mean time, I'm not holding my breath waiting for it to become officially rated as a first-class tourist destination...

Theoretically, our own moon could be mined, and (developed?) by building condos and strip-malls, etc., in the atmospherically-sealed empty mine-shafts loooong before space-travel to other stars becomes practicable for humans... (if ever?...)

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#17
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 12:44 PM

I thought it was only 40 light years away. They're still watching the second season of Mork and Mindy.

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#23
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 3:58 PM

After 1 lightyear, it might as well be 40 million of 'em, or so...

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#28
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 6:01 PM

For any practical sense as we know it now, yes.

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#19
In reply to #16

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 12:57 PM

"At about 40 light-years (235 trillion miles) from Earth, ..."

40 million light-years out and we find things like this (NGC 7331):

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#18

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 12:51 PM

As for the tidal effects? I'm sure 90% the theoretical population would live along the water, but the tide may go out hundreds of miles at times.

The views would be nice, but being a meteorologist would reeealy be a tough job.

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#21
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Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 1:25 PM

That close in? They're probably tidally-locked, like the Moon is to Earth. Their solar system is only about six times larger than Callisto's orbit around Jupiter.

The six inner planets also form a near-resonant chain such that their orbital periods (1.51, 2.42, 4.04, 6.06, 9.1 and 12.35 days) are near-ratios of small integers. This architecture suggests that the planets formed farther from the star and migrated inwards.

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#32

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/23/2017 9:17 PM

These planets were detected because they eclipsed the central star, and the alignment seems pretty lucky. Here is some data I gleaned out of the wiki page:

Companion
(in order from star)

Radius

Semimajor axis
(AU)

Distance from star

(mi)

Diameter of Star (.114xSolar)

(mi)

Angle RadAngle DegProbability

b

1.086 ± 0.035

R⊕

0.011111033230980400.3821.880.12

c

1.056 ± 0.035

R⊕

0.015221415460980400.2815.930.09

d

0.772 ± 0.030

R⊕

0.021 ± 0.0061953000980400.2011.520.06

e

0.918 ± 0.039

R⊕

0.0282604000980400.158.640.05

f

1.045 ± 0.038

R⊕

0.0373441000980400.116.530.04

g

1.127 ± 0.041

R⊕

0.0454185000980400.095.370.03

h

0.755 ± 0.034

R⊕

0.063+0.027
−0.013
5859000980400.073.840.02

The angle calculated in the next to last column is the diameter of the star as seen from the respective planet. If I'm thinking about it correctly, the probability that the orbits would be oriented so that the planets would transit the star (last column) would be this angle divided by 180.

It seems reasonable to assume that the low probability would indicate that there are many more planetary systems that are not detected.

https://en.wikipedia.org/wiki/TRAPPIST-1

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#34

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/24/2017 8:47 AM
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#39

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/24/2017 7:40 PM

Just looking at the orbital data, all seven of these planets have orbital periods of only a matter of days and orbital eccentricities well in excess of Jupiter's moon, Io. And given their extreme proximity to a star having 84 times the mass of Jupiter, I would bet every single one of those planets, like Io, are riddled with active volcanoes as a result of tidal heating.

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#41

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/25/2017 6:05 PM

I for one, agree that my buddy James Stewart should be sent to one of its planet ASAP.

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Anonymous Poster #1
#42

Re: 7 Earth-Size, Habitable-Zone Planets Found Around A Single Star

02/26/2017 2:17 AM

Letters for names are so boring.

I dub thee:

Bashful,

Doc,

Dopey,

Happy,

Sleepy,

Sneezy, and

Grumpy

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