The 'Earth next door' may have a cozy atmosphere — and we could find out in just 2 years

[kevindavis007]

The funny thing about the discovery of Proxima b — the closest planet to our solar system, which is also rocky, Earth-size, and potentially habitable — is that nobody has actually seen it.


Astronomers know it exists because they've seen its gravity tug on and "wiggle" Proxima Centauri, the red dwarf star that it orbits.


But no telescopes in space or on the ground, nor any in serious stages of planning, can directly photograph Proxima b.


It's very distant at 4.2 light-years away from us. Also, its "year" lasts only 11.2 days — an orbit too tight to pick out a planet from the blinding glare of a star.


However, a photograph isn't necessary to ask the most important question about Proxima b, a world that Scientific American has (optimistically) deemed "the Earth next door": Does it have an atmosphere, or is it an airless, barren wasteland like the Moon?


Two researchers at Harvard believe that NASA's James Webb Space Telescope (JWST), scheduled to launch in 2018, could get the job done in record time, and by merely sampling the star system's light.


"It would only take [11 days'] worth of observing time," Avi Loeb, an astrophysicist at Harvard University, told Business Insider.


"With the light we detect, we can ask if this world looks like a bare rock. If it doesn't, there might be an atmosphere, and there might also be an ocean, which life requires," says Loeb, who co-authored a pre-print study on arXiv with Laura Kreidberg, a Harvard astronomer who studies exoplanet atmospheres.


Read more: http://www.isn-news.net/2016/09/the-earth-next-door-may-have-cozy.html

[Joe Wooten]

That planet is probably tidally locked and would more than likely be inhabitable.

[Cripplecreek]

That planet is probably tidally locked and would more than likely be inhabitable.

Seems likely but there are lots of theories and variables on the habitability of tidally locked planets. Deep global oceans like ours are pretty effective at regulating temperature. Volcanism could also be a factor. I think you could expect around half the planet to be covered in ice.

Any life would likely exist in the twilight ring. I would think weather patterns would be pretty stable with cool winds flowing from the dark side to the day side only to rise and head to the darkness.

Its all cool stuff to ponder on.

[Gefn]

Seems likely but there are lots of theories and variables on the habitability of tidally locked planets. Deep global oceans like ours are pretty effective at regulating temperature. Volcanism could also be a factor. I think you could expect around half the planet to be covered in ice.

Any life would likely exist in the twilight ring. I would think weather patterns would be pretty stable with cool winds flowing from the dark side to the day side only to rise and head to the darkness.

Its all cool stuff to ponder on.

It might be a wonderful place to visit someday. I will try to visit it in my dreams.

[Joe Wooten]

The habitability of Proxima b is doubtful

http://www.centauri-dreams.org/?p=36452

[Oceander]

The habitability of Proxima b is doubtful

http://www.centauri-dreams.org/?p=36452

I wonder if the fact that it's tidally locked would have any bearing on how badly the cmes, x-rays and gamma rays would affect the dark side of the planet.  Most likely the damage to the atmosphere would have global effects, but the backside might still present some habitable scenarios with contained armospheres inside modules.

[kevindavis007]

I wonder if the fact that it's tidally locked would have any bearing on how badly the cmes, x-rays and gamma rays would affect the dark side of the planet.  Most likely the damage to the atmosphere would have global effects, but the backside might still present some habitable scenarios with contained armospheres inside modules.

But the habitable side will be constant darkness.

[Oceander]

But the habitable side will be constant darkness.

Most likely.  However, if there are constant CMEs, perhaps there might be backlighting from those as they pass the planet.  There might also be spillover just behind the dark/light border that would be useful.  Visible light is, I think, more likely to bend and deflect than, say x-rays or gamma rays.

[geronl]

Sounds like it would be worse than Mercury

[Cripplecreek]

The habitability of Proxima b is doubtful

http://www.centauri-dreams.org/?p=36452

Obviously our best bet will always be brighter hotter less active stars where planets will have longer orbits and are less likely to be tidally locked.

Personally I think our best bet for life around red dwarfs would be moons of gas giants that orbit at the outer edge of the habitable zone.

The variables are pretty much infinite.

[Gefn]

Obviously our best bet will always be brighter hotter less active stars where planets will have longer orbits and are less likely to be tidally locked.

Personally I think our best bet for life around red dwarfs would be moons of gas giants that orbit at the outer edge of the habitable zone.

The variables are pretty much infinite.

There are trillions of stars and billions of planets - how many would be in Goldilocks zones I don't know. Thousands? What I do know is our children , grandchildren, great grandchildren, will be future space explorers and what wonders they will see.

That is, if we don't blow ourselves up before then.

[Doug Loss]

The funny thing about the discovery of Proxima b — the closest planet to our solar system, which is also rocky, Earth-size, and potentially habitable — is that nobody has actually seen it.

If we're serious about actually seeing extrasolar planets, we need to mount some FOCAL missions:

https://en.wikipedia.org/wiki/FOCAL_(spacecraft)
http://www.centauri-dreams.org/?p=785

[jmyrlefuller]

That planet is probably tidally locked and would more than likely be inhabitable.

There are two possibilities, at least according to what's on Wikipedia: one being tidally locked and the other being a resonance that would rotate the planet every 5 to 7 days (out of the 11-day "year"). The latter, obviously, would provide the best chance for habitability. It depends on the eccentricity of the orbit, which we don't yet know.