You must log in or register to comment.

[deleted] t1_j2br4rh wrote



[deleted] t1_j2bw8ik wrote



[deleted] t1_j2bwevo wrote



[deleted] t1_j2c2kdb wrote



[deleted] t1_j2c3wkr wrote



CrimsonEnigma t1_j2bno8o wrote

Just to note: Alpha Centauri A is not a red dwarf; it’s actually a G2V star, just like the Sun.


GeorgeOlduvai t1_j2c5n7f wrote

The red dwarf companion is Proxima, IIRC. Alpha Centauri A and B are yellow and orange stars, right?


yanessa t1_j2c8j3v wrote

A (Rigil) G2V

B (Toliman) K1V

C (Proxima) M5.5Ve, both UV-Ceti and BY Draconis variable


CrimsonEnigma t1_j2c9imt wrote

Yea, Proxima Centauri is the red dwarf. I'm not sure about Alpha Centauri B's color. Star color is weird in and of itself; while we call stars like Alpha Centauri A and the Sun "yellow dwarfs", they're actually both white - the Sun only looks yellow because the atmosphere scatters more light in the blue end of the spectrum than the red end. Were you standing on the moon and staring at the Sun, it wouldn't appear yellow at all, though staring at the Sun usually isn't a good idea.

Incidentally, Proxima Centauri has an earth-sized planet around it that's on the inner edge of the habitable zone, though probably isn't actually habitable for the reasons OP pointed out.

There is a very tentative candidate for Alpha Centauri A. If confirmed, it would be a Neptune-sized planet also in the habitable zone (though barely), though again I must emphasize that this is *extremely* tentative. These candidates pop up around stars from time to time and a lot of them turn out to just be artifacts in the data.

If it is real, though, it should be big enough, far enough away from Alpha Centauri A, and close enough to our own solar system that we might be able to observe it with the JWST.

That's a long time off, though.


thewerdy t1_j2cj9mc wrote

Fun fact, you can see Alpha Centauri B in the night sky of Pandora in the first film. It's an unusually bright star.


FormulaNewt t1_j2bqavq wrote

You mean one where it plays the same songs over and over and if you try to skip one you have to listen to a bunch of ads?


MattTheStrategist t1_j2btxe3 wrote

Nah I think they're talking about the Pandora with all the Vault Hunters and bandits.


Arkanial t1_j2closr wrote

Took me like 30 seconds to realize the title was talking about Avatar and not Borderlands. My first thought was “a world where like everything is out to kill you? Yeah, maybe.” Then I realized they meant Avatar and I’m pretty sure we’re more likely to find murder world.


Thedracus t1_j2brdgw wrote

I've never heard an ad on Pandora. You just have to subscribe. Then you can listen to anything online or offline


kneaders t1_j2bm22l wrote

Visiting it is a much bigger problem than finding it


mwebster745 t1_j2bwqwt wrote

Actually the film is interesting in subtly addressing the magnetosphere thing. A moon around a gas giant would be at risk of being fried by radiation focused by the planet's own magnetosphere. This is the challenge with Europa, and why the Europa clipper mission won't ever actually orbit Europa itself. In avatar you repeatedly see areas of massive magnetic flux, generally where the 'spirit trees' are. You can tell from large rock rings standing on end, following the contouring of magnetic field lines. This is also close to the 'flying mountains' which are suspended by such a magnetic field. The new movie was a bit different, but the original mentioned 'unobtanium' being mined which was a natural room temperature superconductor causing the magnetic fields. Generally small planets and moons solidify and a solid (ish) core like Mars doesn't produce a strong magnetic field like earth has. A small moon like Pandora flying free would solidify and lose a magnetic field, then have it's atmosphere stripped by solar wind, again like Mars, but an exo-moon would have massive gravitational tidal flexing to keep it's core active just like Io and to a lower degree Europa.

So kinda, outside of the magic 'unobtanium' it could exist


The_Solar_Oracle t1_j2bzhwh wrote

Pandora is not actually so small that its core would necessarily be solid. Jupiter's largest moon, Ganymede, is known to have its own magnetic field brought about by a partially molten core, and it's only 2.5% the mass of Earth! By contrast, Pandora is said to be 72% the mass of Earth, which makes it significantly more massive than Mars and slightly less massive than Venus. What really determines whether or not a celestial body's core stays molten on its own probably boils down to a favorable amount of transuranic elements in addition to size. After all, half of Earth's own interior energy can be attributed to the decay of radioisotopes and the occasional natural fission reactor. The presence of tectonic activity might also be important, which could explain some differences between Earth and Venus in regards to their interior activity.

It can also take a very long time for stellar winds to strip away another celestial body's atmosphere, and there are means to replenish any losses like volcanic outgassing.


ICLazeru t1_j2cpfly wrote

In the case of a moon orbiting a much more massive body, it's also possible that the gravitational tide of the larger body keeps the core molten. This would only work for so long as Pandora had rotational momentum of course, and over time the body would become tidally locked with the same side always facing its larger partner.


The_Solar_Oracle t1_j2cqtx9 wrote

Pandora is probably tidally locked, but the kind of tidal forces responsible for prolonged geological activity for moons like Io also require special resonance orbits with other satellites. Europa and Ganymede have a 2:1 and 4:1 orbital resonance with Io respectively, and these resonances maintain Io's orbital eccentricity. Without this elegant dance of moons, the same tidal forces that physically distort Io would also circularize its orbit.

Interestingly, though, Pandora is also reliably depicted as being fairly close to Polyphemus (a planet that is itself slightly less massive than Jupiter). While there doesn't appear to be a canon figure available on the internet in regards to its orbital period (and, thus, lengths of its days), there is no doubt in my mind that James Cameron has figures to this end for use by the production team.


ICLazeru t1_j2cpllo wrote

Why would the mountains be floating rather than just drifting toward the magnetic pole?


s1ngular1ty2 t1_j2bv4q8 wrote

Can one exist? Maybe... Can we ever visit it? Probably not...


name_NULL111653 t1_j2bwuz0 wrote

"We" is ambiguous. Humans as we know them? Probably not. Some genetic variation / descendant of humans eons from now? Probably could visit it. Extremely advanced construct / "AI" / created being? Almost definitely could go interstellar. Artificial and biological hybrid humans (cyborgs / posthuman bodies)? Also likely if they're ever made.


Zen_Badger t1_j2bvspw wrote

First off you would have to have a gas giant orbiting in the habitable zone for a terrestrial type planet. I consider that to be highly unlikely


name_NULL111653 t1_j2bx9a1 wrote

For exomoons, the gas giant does not necessarily have to be in the habitable zone, due to a variety of factors such as tidally induced geological activity. I cite Titan. Imagine if it's subsurface lakes were nitrogen and oxygen (instead of ethane etc.) It would absolutely be habitable by humans, despite the parent planet being far outside our sun's relatively small habitable zone.


Zen_Badger t1_j2byfue wrote

It would hardly be a tropical paradise as depicted in Avatar tho


name_NULL111653 t1_j2byoj2 wrote

Agreed. It would be about like Antarctica. But with stronger tidal forces, or (most likely) on a more recently formed moon, it would be possible. Uncommon, but much more likely than a gas giant in the habitable zone.


DreamChaserSt t1_j2c9rtz wrote

Assuming I'm reading your comment correctly, we have found plenty of gas giants in the habitable zone, more than the number of terrestrial and super-Earth sized planets even. One notable example is Mu Arae b, over 1.6x more massive than Jupiter and could certainly hold onto a larger moon. It's orbiting an G-type star older than the sun about 50 ly away.


AmAProudIdiot t1_j2c4u46 wrote

Alpha Centauri A is not an M-type red dwarf, it is a G2V, something similar to Sol. I don't know Avatar lore, so I'm not sure if you mean Proxima Centauri.

If you're discussing such an exomoon in AC-A, it's definitely feasible, the problems are whether or not a natural satellite can be that large.

If you're discussing Proxima Centauri, then it's still feasible, but less likely. The exomoon will have to be located within the gas giant's magnetosphere, since M-type stars are so active, potentially close enough for a large object like the exomoon to be ripped apart. This wouldn't be an issue with ultra-cool M-types, but PC is not one of them.

I'll have to say though, the plants and other wildlife would be completely inaccurate, especially the color.


FrostyAcanthocephala t1_j2cinm0 wrote

Yes, and there's a scantily clad Na'Vi girl waiting for you there.


maria_slayer t1_j2bmxn5 wrote

Even if we were to find one we would still lack the ability to travel there. Even traveling to mars is a lengthy journey, just existing the solar system alone is impossible within a normal human lifetime. But we could still discover one and research it which i think is equally cool. The james webb space telescope has a special tool that checks the atmosphere of distant planets which could help them find planets that sustains life. That’s probably the only way to research planets that they deem capable of sustaining life for now atleast


gyunikumen t1_j2cguh1 wrote

In the avatar universe, the interstellar starships can reach 0.7 C / speed of light using Antimatter - Matter engines. We currently understand enough about Antimatter physics to know such engines and speeds are theoretically possible.

Therefore, the time of flight to Prox A, ~4 light years away, should roughly take ~6 years.


_B_Little_me t1_j2cclwy wrote

But would rockets actually work on that avatar planet?


vetiarvind t1_j2ceqfk wrote

A watery planet? Yes. A planet with near-human looking aliens with hair on top of their head? Almost 0. The upright posture with opposable thumb design is clearly not very common, as evidenced by the fact that the hominid species came into existence for only about a million years in a timeline that spans 530 million years for vertebrates to come into existence. (or 1 million since the 100+ million years that mammals existed) Seems a huge fluke that a primate-like species with 3 cones for finding fruit that eventually becomes upright on the plains will ever popup in the universe.


nickparadies t1_j2cp6h0 wrote

Isn’t there an alternative theory that a human-like body plan is the best design for an intelligent species and therefore we should expect to see more aliens like us out there?


watkinobe t1_j2cfcv6 wrote

Define "Pandora-like." Do you mean one that has a lot of bioluminescent flora and fauna with large blue humanoids? I seriously doubt we can imagine what habitable planets actually look like, but I doubt they will bear much resemblance to the vision of a Hollywood film producer.


AhRedditAhHumanity t1_j2ch5we wrote

It’s about as realistic as a human from another galaxy far far away named Han Solo who looks, acts and dresses like a white 70s American human and uses all the same slang. Oh and speaks English.


CubesFan t1_j2cjjmg wrote

Of course not. It's made from unobtainium. Literally tells you right there it is unobtainable.


SpartanJack17 t1_j2copf7 wrote

Hello u/lemonny3663, your submission "Could we find a Pandora-like planet in real life?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.