7 earth size planets orbiting same star!!

[Romulan_spy]

Big news in astronomy. Scientists have found 7 earth size planets orbiting the same star, called Trappist-1, about 39 l.y away.
http://www.popsci.com/seven-earth-size-planets-live-around-nearby-star

 

[Squiggy]

A little inside baseball: If the announcement is coming from the basement of NASA HQ - it's not that big of a deal.

 

[Relayer1]

A I the only one that thought Firefly ?

 

[B.J.]

A little inside baseball: If the announcement is coming from the basement of NASA HQ - it's not that big of a deal.

They had a big press conference on this one.

But the really cool thing about this discovery is that *three* of the planets are within the star's habitable zone. And all seven could possibly have liquid water, under the right conditions.
https://www.nasa.gov/press-release/...h-of-earth-size-habitable-zone-planets-around
https://exoplanets.nasa.gov/trappist1/

NASA's also having a reddit AMA in about 15 minutes.

 

[Romulan_spy]

What I find exciting about this discovery is that it confirms that potentially habitable planets are much more common than we once believed. It appears that earth size planets might be abundant in our galaxy.

 

[Squiggy]

They had a big press conference on this one.

Yes, but the setting shows you how important NASA thinks this is. If this was a bigger story they would've used a larger space to hold more press. I know that the basement studio at NASA TV can only hold 5-10 reporters. The auditorium holds 10 times that.

(I used to work there).

 

[137th Gebirg]

A I the only one that thought Firefly ?

Close. I thought the Cyrannus System from Battlestar Galactica.

 

[Mark_Nguyen]

I also thought about the Verse. Those guys supposedly inhabited a quintuple star system if you believed the RPGs that came after, though.

I can totally accept the notion that most, if not the overwhelming majority of stars have planets of SOME sort around them. I can only hope that within our lifetimes technology will be developed that will allow us to determine whether or not a given world can sustain life as we know it to a firm degree of confidence. I'd like to leave this world knowing that there is a real chance of another one being out there somewhere.

Point being, that I think the next big challenge for exoplanet research is to change the primary focus from determining the existence of potentially habitable planets to determining the existence of actually inhabited planets. Who knows if that's even possible, but a generation ago we could know exoplanets existed in the first place, so...

Mark

 

[Relayer1]

Close. I thought the Cyrannus System from Battlestar Galactica.

I like the cut of your jib.

 

[Dryson]

Big news in astronomy. Scientists have found 7 earth size planets orbiting the same star, called Trappist-1, about 39 l.y away.
http://www.popsci.com/seven-earth-size-planets-live-around-nearby-star

This is a program that needs crowd funding for all to be involved with.

39 light years away is nothing for a telescope like Hubble to view.

 

[diankra]

This is a program that needs crowd funding for all to be involved with.

39 light years away is nothing for a telescope like Hubble to view.

The Webb telescope should be able to get spectrograph data on these possibles, as the low-energy output of the star won't swamp them. That should allow confirmation (or not) of water.
So, in the works already, within 10 years maybe.

 

[Crazy Eddie]

It's a VERY small star. Not much larger than Jupiter it seems, but with a hell of a lot more mass. The planets orbit so close that the inner planet is as close to the sun as Callisto is to Jupiter.

So if anything, this system would be comparable to, say, the Lucifer system from the "Odyssey" novels.

All seven of these worlds are yours except TRAPPIST-d. Attempt no landings there.

 

[Asbo Zaprudder]

TRAPPIST-1 has an estimated 8% of the Sun's mass whereas Jupiter has 0.1% so about 80 Jupiter masses. As an ultracool dwarf star, its flare activity is believed to be lower than more massive red dwarfs but it still produces copious XUV and X radiation that could be problematic for habitable biospheres.

We present an XMM-Newton X-ray observation of TRAPPIST-1, which is an ultracool dwarf star recently discovered to host three transiting and temperate Earth-sized planets. We find the star is a relatively strong and variable coronal X-ray source with an X-ray luminosity similar to that of the quiet Sun, despite its much lower bolometric luminosity. We find L_x/L_bol=2-4x10^-4, with the total XUV emission in the range L_xuv/L_bol=6-9x10^-4, and XUV irradiation of the planets that is many times stronger than experienced by the present-day Earth. Using a simple energy-limited model we show that the relatively close-in Earth-sized planets, which span the classical habitable zone of the star, are subject to sufficient X-ray and EUV irradiation to significantly alter their primary and any secondary atmospheres. Understanding whether this high-energy irradiation makes the planets more or less habitable is a complex question, but our measured fluxes will be an important input to the necessary models of atmospheric evolution.

https://arxiv.org/abs/1605.01564 (published before the count of planets was increased)

What I find exciting about this discovery is that it confirms that potentially habitable planets are much more common than we once believed. It appears that earth size planets might be abundant in our galaxy.

Yes, the techniques for planetary detection tend to skew away from low mass planets. I suspect planetary mass distribution likely follows a power law with more low mass planets than high mass ones but at present the distribution peaks at about 6 earth masses.

https://www.lpl.arizona.edu/~renu/malhotra_preprints/2015c-malhotra.pdf

Extrapolation of a power-law mass distribution fitted to our measurements ... predicts that 23% of stars harbor a close-in Earth-mass planet (ranging from 0.5 to 2.0 Earth masses). Theoretical models of planet formation predict a deficit of planets in the domain from 5 to 30 Earth masses and with orbital periods less than 50 days. This region of parameter space is in fact well populated, implying that such models need substantial revision.

https://kepler.nasa.gov/news/keplerinthenews/index.cfm?FuseAction=ShowNews&NewsID=75 (slightly old paper -- I expect the estimates have since been revised)

 

[SPCTRE]

 

[Ronald Held]

Three might be in the habitual done. Due to the star being a flare star and depending on the current atmosphere density and composition, the surfaces might be uninhabitable.

 

[Crazy Eddie]

TRAPPIST-1 has an estimated 8% of the Sun's mass whereas Jupiter has 0.1% so about 80 Jupiter masses.

I know that. I was mainly alluding to size in the absolute sense, meaning the radius of the photosphere and the diameter of its orbits. At 80 Jupiter masses it's probably not much more than twice the diameter of Jupiter.

 

[psCargile]

And, they are most likely tidally locked, or damn near close to it.

I won't get excited about potential neighbors until they find an Earth-like planet.

 

[Asbo Zaprudder]

I know that. I was mainly alluding to size in the absolute sense, meaning the radius of the photosphere and the diameter of its orbits. At 80 Jupiter masses it's probably not much more than twice the diameter of Jupiter.

Right. I wasn't disagreeing with your post -- just adding some numbers to quantify your statement about the relative mass. It'll be interesting to see what the JWST tells about the system when that instrument becomes available -- perhaps next year or in 2019.

 

[Crazy Eddie]

Are they, like, planning to LAUNCH the Webb at some point? Last I heard the thing is pretty much just the world's most expensive paperweight until the SLS gets fully certified, but I haven't been following rocket news lately.

 

[diankra]

As an astrophycist friend said to me 10 years ago, "Well, what do you expect if you name it after a politician rather than a scientist?"