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1.5 AU from Proxima (so 50% farther than earth is from the sun), which is itself much less luminous than the sun? I'd imagine it's a very, very cold planet and

1.5 AU from Proxima (so 50% farther than earth is from the sun), which is itself much less luminous than the sun? I'd imagine it's a very, very cold planet and receives many times less light than earth does. Neat to find a planet, but it doesn't sound like one humans would want to have much to do with.

m4rtink 7y ago
Hey, more mass for habitats and other stuff once we get there. :-) Planets are mass inefficient anyway. ;-)
- eloff 7y ago
  Yeah, people keep focusing on Mars as a habitat, but it makes so much more sense to build in orbit around earth. So much closer when you need something and your internet latency would be great. But Bezos has the right idea, keep people on the planet and put the things you don't want on the planet in space rather, like industry. Even that makes little sense until you're sourcing the resources from outside earth.
LatteLazy 7y ago
Interestingly it's also a "flare star", so it occasionally gets 10 times brighter for a few minutes (over the whole spectrum, including xrays and gamma). https://en.wikipedia.org/wiki/Flare_star https://en.wikipedia.org/wiki/Flare_star
- ourlordcaffeine 7y ago
  I wonder if this combined with a greenhouse atmosphere could keep it warm enough between flares. If it has life, I wonder if the flare cycle would be just as important as the seasonal cycle on earth.
  - Rusky 7y ago
    Reminds me of this Vernor Vinge novel: https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky Set around a star that alternates between bright and dim, with a species that hibernates during the dim periods.
    - LatteLazy 7y ago
      Have you read Three body problem? Park of that is about a species that likes on a planet in a (chaotic) three star system. They alternate between intense heat and freezing darkness with the occasional "golden age". The books are more earth centred but very good...
hazeii 7y ago
Plus at 5.8 times (+-1.9) Earth's mass it's only low mass compared to most extrasolar planets. Still, there may be life that's happy with slow and heavy.
- arethuza 7y ago
  That massive a planet might have a thick enough atmosphere to compensate for its distance from the star? e.g. Wasn't Mars 'warm' for quite a long time and only became really cold once it lost most of its atmosphere due to its small mass?
  - PopeDotNinja 7y ago
    Titan has a darn thick atmosphere, and it's a moon of Saturn. I don't see any reason the planet from the article couldn't have an atmosphere.
    - saiya-jin 7y ago
      Isn't some of the atmosphere being replenished from its inner geology? Also IIRC Mars lost its atmosphere due to solar winds and lack of good protective magnetic field, unlike earth with its radioactivity-fed one. I would expect Titan has it neither, but is much farther from Sun so solar winds must be a tiny fraction of intensity out there.
      - ourlordcaffeine 7y ago
        >IIRC Mars lost its atmosphere due to solar winds and lack of good protective magnetic field Someone in the know correct me if I'm wrong, but I believe this is no longer the main theory, as solar wind ablation is too slow to make such a huge impact. I believe the popular explanation now is that geological reactions, i.e. gas reacting with rocks and being sequestered, played a larger part.
        zipwitch 7y ago
        Solar wind as the culprit was still being tossed around in 2017. https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space https://www.nasa.gov/press-release/nasas-maven-reveals-most-... "The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate."
tomrod 7y ago
If it is tidally locked there may be a habitable zone on the planet.
lmilcin 7y ago
On the other hand it has much more mass than Earth and so there is slim possibility it has dense atmosphere. I believe dense atmosphere to be more important that perfect temperature for habitability.
- eloff 7y ago
  Yes, just look at Venus. Probably atmosphere composition and density matters more than distance from the sun.
  - lmilcin 7y ago
    Actually, what I meant is it is easier to build for cold than it is to build for vacuum. Atmosphere also contains many important elements which would be hard to get from planet's crust. As to Venus... it is CLOSER to the Sun than Earth is, not farther.
    - eloff 7y ago
      I'm aware of the order of the planets, what I mean to say is Venus's climate has much less to do with its distance from the sun than its atmospheric composition. It'd be cooler if you moved it to Mar's orbit, but still much hotter than Earth, even although solar radiation is dropping off proportionally with r squared.
mongol 7y ago
Same distance as Mars to Sun so not that far away. As long as there is a chance for it to harbour life I would say it is interesting.

m4rtink 7y ago

Hey, more mass for habitats and other stuff once we get there. :-) Planets are mass inefficient anyway. ;-)

eloff 7y ago
Yeah, people keep focusing on Mars as a habitat, but it makes so much more sense to build in orbit around earth. So much closer when you need something and your internet latency would be great. But Bezos has the right idea, keep people on the planet and put the things you don't want on the planet in space rather, like industry. Even that makes little sense until you're sourcing the resources from outside earth.

LatteLazy 7y ago

Interestingly it's also a "flare star", so it occasionally gets 10 times brighter for a few minutes (over the whole spectrum, including xrays and gamma). https://en.wikipedia.org/wiki/Flare_star https://en.wikipedia.org/wiki/Flare_star

ourlordcaffeine 7y ago
I wonder if this combined with a greenhouse atmosphere could keep it warm enough between flares. If it has life, I wonder if the flare cycle would be just as important as the seasonal cycle on earth.
- Rusky 7y ago
  Reminds me of this Vernor Vinge novel: https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky Set around a star that alternates between bright and dim, with a species that hibernates during the dim periods.
  - LatteLazy 7y ago
    Have you read Three body problem? Park of that is about a species that likes on a planet in a (chaotic) three star system. They alternate between intense heat and freezing darkness with the occasional "golden age". The books are more earth centred but very good...

hazeii 7y ago

Plus at 5.8 times (+-1.9) Earth's mass it's only low mass compared to most extrasolar planets. Still, there may be life that's happy with slow and heavy.

arethuza 7y ago
That massive a planet might have a thick enough atmosphere to compensate for its distance from the star? e.g. Wasn't Mars 'warm' for quite a long time and only became really cold once it lost most of its atmosphere due to its small mass?
- PopeDotNinja 7y ago
  Titan has a darn thick atmosphere, and it's a moon of Saturn. I don't see any reason the planet from the article couldn't have an atmosphere.
  - saiya-jin 7y ago
    Isn't some of the atmosphere being replenished from its inner geology? Also IIRC Mars lost its atmosphere due to solar winds and lack of good protective magnetic field, unlike earth with its radioactivity-fed one. I would expect Titan has it neither, but is much farther from Sun so solar winds must be a tiny fraction of intensity out there.
    - ourlordcaffeine 7y ago
      >IIRC Mars lost its atmosphere due to solar winds and lack of good protective magnetic field Someone in the know correct me if I'm wrong, but I believe this is no longer the main theory, as solar wind ablation is too slow to make such a huge impact. I believe the popular explanation now is that geological reactions, i.e. gas reacting with rocks and being sequestered, played a larger part.
      - zipwitch 7y ago
        Solar wind as the culprit was still being tossed around in 2017. https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space https://www.nasa.gov/press-release/nasas-maven-reveals-most-... "The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate."

tomrod 7y ago

If it is tidally locked there may be a habitable zone on the planet.

lmilcin 7y ago

On the other hand it has much more mass than Earth and so there is slim possibility it has dense atmosphere. I believe dense atmosphere to be more important that perfect temperature for habitability.

eloff 7y ago
Yes, just look at Venus. Probably atmosphere composition and density matters more than distance from the sun.
- lmilcin 7y ago
  Actually, what I meant is it is easier to build for cold than it is to build for vacuum. Atmosphere also contains many important elements which would be hard to get from planet's crust. As to Venus... it is CLOSER to the Sun than Earth is, not farther.
  - eloff 7y ago
    I'm aware of the order of the planets, what I mean to say is Venus's climate has much less to do with its distance from the sun than its atmospheric composition. It'd be cooler if you moved it to Mar's orbit, but still much hotter than Earth, even although solar radiation is dropping off proportionally with r squared.

mongol 7y ago

Same distance as Mars to Sun so not that far away. As long as there is a chance for it to harbour life I would say it is interesting.