Fascinating Alien Worlds

With over 100 billion Earth-like planets now thought to exist in the Milky Way, the possibilities for worlds that escape our imagination seem now an endless reality. These are some of the fascinating, naturally occurring and physically possible habitable worlds of our galaxy, some of which writers have imagined and others which scientists have predicted:

Images and detailed info on each of the worlds:
The Fascinating Worlds of the Milky Way

Just a few years ago we didn't know if other Earths existed in space, today science is catching up with science fiction painting the possible picture of a galaxy teeming with trillions of intelligent beings of unimaginable cultures inhabiting unimaginable worlds.

Rocheworlds: Egg-shaped tidally locked double planets, just outside the Roche limit, sharing a common atmosphere.

Naturally occurring habitable rings: Gas tori, one million km thick, orbiting old neutron stars. Enough pressure at their centers and globs of water make life possible.

Super-habitable Earths: The Eden's of Space, lush worlds with shallow oceans, fractionate continents and extended tropical zones.

Double habitable planets: For humans it would seem Contact is light years away but for many extraterrestrial civilizations it could be at the distance of one Apollo mission. These are stable double Earths separated by only half the diameter of each of the worlds!

Super-habitable solar systems: Stars with multiple Earth-like planets (up to 60?) Some astronomers now believe that systems with one habitable world, like ours, could be an oddity of space and stars with more than one Earth-like world, the norm. The twelve colonies of Kobol could be out there.

Tatooine-like planets: Double sunset worlds. We knew they could exist but recent computer simulations have demonstrated that rocky earth-like planets are as likely to form around binary stars as they are around single stars.

Earth-like worlds with eccentric orbits: Take Earth's seasons to the extreme. This worlds would have winters lasting years and life would wake up from hibernation only once the planet gets close to its stellar orb.

What other extraordinary realities could exist all around us?

The best way to describe this thread:

This tickles my fancy.

Thank you for this information, very good read.

I have always dreamt about the double habitable planets scenario.

Living two different lives at once on two different planets right next to each other seems like a challenge.

a reply to: thyextendedself I read the stories on this and it just reaffirms my beliefs that we are alone because the much more advanced look at earth as we look at an ant farm...an enigma of moronic proportions. But I digress, the limits set upon our universe are only limited to the extent of the human mind. Imagine a galaxy where there are no limits...and then one greater than that...and one greater.....and one greater....

originally posted by: thyextendedself

With over 100 billion Earth-like planets now thought to exist in the Milky Way, the possibilities for worlds that escape our imagination seem now an endless reality. These are some of the fascinating, naturally occurring and physically possible habitable worlds of our galaxy, some of which writers have imagined and others which scientists have predicted:

Wonderful thread. S+F

See my comments below on each of these....

Rocheworlds: Egg-shaped tidally locked double planets, just outside the Roche limit, sharing a common atmosphere.

Theorized but not found yet..

There's a wonderful romantic sci-fantasy movie based on one though. Check out Upside Down on Netflix.

Naturally occurring habitable rings: Gas tori, one million km thick, orbiting old neutron stars. Enough pressure at their centers and globs of water make life possible.

Possible but neutron stars give off a lot of ionizing radiation so whether or not life would be possible under those conditions is an open question.

Super-habitable Earths: The Eden's of Space, lush worlds with shallow oceans, fractionate continents and extended tropical zones.

Almost certain to exist and not too far away from our solar system either. We may have even found a few but don't know it yet because our instruments aren't sensitive enough to tell they are super habitable. Stay tuned for the James Webb Space Telescope!

Double habitable planets: For humans it would seem Contact is light years away but for many extraterrestrial civilizations it could be at the distance of one Apollo mission. These are stable double Earths separated by only half the diameter of each of the worlds!

There are rumors that a double planet may be lurking in the Kepler data but not yet confirmed as such... We'll see....

Super-habitable solar systems: Stars with multiple Earth-like planets (up to 60?) Some astronomers now believe that systems with one habitable world, like ours, could be an oddity of space and stars with more than one Earth-like world, the norm. The twelve colonies of Kobol could be out there.

We know of multiple systems with more than one Earth size planet in the habitable zone, in one case perhaps as many as 3, but 60? That seems a bit of a stretch. We do however know of some very tight orbiting planets so it would not be shocking if a system were found with 10 planets in the habitable zone. It is possible to have 60 planets in tight orbits in a system but I doubt most of those would be in the habitable zone.

On the other hand, it looks like most stars may have on average, two planets in their habitable zone. If so, then we were a little unlucky just getting stuck with one.

Tatooine-like planets: Double sunset worlds. We knew they could exist but recent computer simulations have demonstrated that rocky earth-like planets are as likely to form around binary stars as they are around single stars.

Already found! Not only one but several. In fact amateur, citizen scientists found the 2nd known Tatooine planet using the Zooniverse citizen science project called Planet Hunters

Tatooine-like planets are now thought to be very common.

Earth-like worlds with eccentric orbits: Take Earth's seasons to the extreme. This worlds would have winters lasting years and life would wake up from hibernation only once the planet gets close to its stellar orb.

Almost found. One of many Jupiter mass planets in such an orbit. There are couple Earth sized Kepler habitable zone planet candidates which have highly eccentric orbits.

What other extraordinary realities could exist all around us?

How about my favorite which wasn't mentioend.

Earth-like habitable exomoons: You've seen them in Sci-fi. Pandora, Endor, etc. Far from the stuff of sci-fi, they could actually exist. Not only that but we may find the first one perhaps as soon as this year!

BTW: If all this stuff interests anyone, NASA/NASA TV is having a live event dedicated to it on April 7.

From the press release:

April 1, 2015
MEDIA ADVISORY M15-050
Our Solar System and Beyond: NASA’s Search for Water and Habitable Planets

NASA Television will air an event from 1 – 2 p.m. EDT on Tuesday, April 7, featuring leading science and engineering experts discussing the recent discoveries of water and organics in our solar system, the role our sun plays in water-loss in neighboring planets, and our search for habitable worlds among the stars.
The event, which is open to the public, will take place in the Webb Auditorium at NASA Headquarters, 300 E Street SW in Washington.

The panel also will highlight the fundamental questions NASA is working to answer through its cutting-edge science research: Where do we come from? Where are we going? Are we alone?
Panel participants include:

John Grunsfeld, astronaut and Science Mission Directorate associate administrator, NASA Headquarters, Washington
Ellen Stofan, chief scientist, NASA Headquarters
James Green, director of Planetary Science, NASA Headquarters
Jeffrey Newmark, interim director of Heliophysics, NASA Headquarters
Paul Hertz, director of Astrophysics, NASA Headquarters

For NASA TV streaming video, schedules and downlink information, visit:
www.nasa.gov...

And later this month there is this science conference taking place:

if this is possible then ring worlds might be more feasible: phys.org...

and the sci-fi reference is Niven's ring world series like the Integral Tree and so on.

because, you see, the idea of a thick atmosphere and a inward planetary migration where the star's tendency to blow off the planets atmosphere is banked by a fortunate orbital distance and by the volume of the large atmosphere. if that can happen to a mini-neptune then it is not a stretch for the same sort of thing around a neutron star with a huge volume of gas around it. degree not kind.

originally posted by: thyextendedselfRocheworlds: Egg-shaped tidally locked double planets, just outside the Roche limit, sharing a common atmosphere.

these sound the coolest.

And the most amazing thing of all is that these planets are just in the Milky Way...there's billions of other galaxies out there each Galaxy with it's own unique worlds...who knows whats truly out there

a reply to: thyextendedself

Yes if you look down on the Milky Way it has spires or arms we are in one of the arms and I am sure there are more "Earths" in our part and throughout the rest of the MW. In away I have always wondered what I would do If I came upon a landed UFO with an open door. Try to communicate with the occupants? If I did the first I would ask is what does your home and planet look like. Far off other worlds.

Thank you for this information, very good read.

originally posted by: LA1IMPALA
a reply to: thyextendedself

Yes if you look down on the Milky Way it has spires or arms we are in one of the arms and I am sure there are more "Earths" in our part and throughout the rest of the MW. In away I have always wondered what I would do If I came upon a landed UFO with an open door. Try to communicate with the occupants? If I did the first I would ask is what does your home and planet look like. Far off other worlds.

You're going to love this app then....



You can download it here for PC and Mac:

NASA App: Eyes on Exoplanets

a reply to: JadeStar

WOWSERS that is something

Thanks for the link.
NASA App: Eyes on Exoplanets

I ran this with a large screen 4k tv, using stereo option (just the colored glasses version) and hard to describe how awesome this application is. Nothing like it.

originally posted by: charlyv
Thanks for the link.
NASA App: Eyes on Exoplanets

I ran this with a large screen 4k tv, using stereo option (just the colored glasses version) and hard to describe how awesome this application is. Nothing like it.

You're welcome. Your tax dollars at work (if you are a US citizen).

That's the thing, NASA makes some amazing apps but often the people who are most interested in this stuff, like people into Aliens and UFOs are completely unaware of them because they don't frequent NASA or other space science sites (often I think this is due to the NASA bashing from certain quarters of the field).

BTW: If you think that is amazing on your 4K TV... check this one out. It is not made by NASA but by one lone Russian software engineer and it is STUNNING and SPECTACULAR (though a lot more speculative):




You can download it from here for PC. Sorry, no Mac version though one might be developed in the future. It's well worth running on a PC or a Mac using Boot Camp though.



It also features in these videos I posted:





Like the NASA Eyes on Exoplanets app it uses real astronomy data on exoplanets from Kepler and other observatories but unlike the NASA Eyes app it also can procedurally generate planets, moons, rings and other bodies based on a real physics engine. It can even generate basic forms of plant life which react to the type of light it they receive. It's not just confined to our galaxy either, it's a Universe explorer both of what we know, and what is possible based on the laws of chemistry and physics.

I use it in space visualization work all the time like this one I made of a sunrise, sunset, eclipse sequence on hypothetical habitable exomoon circling around the real life exoplanet known as Upsilon Andromedae d:



And this speculative look at the newly discovered nearby, Earth sized habitable world known as EPIC 201367065 d which as you can see, while tidally locked could possibly support Earth like conditions on part of the planet if the upper atmosphere circulated well.

It orbits a small red dwarf star 147 light years away in the constellation LEO and was announced earlier this year.

I basically fed Space Engine the basic data we know about the planet, size, estimated mass, received stellar flux, and let it do the rest and this was the result:



BTW: The end of that video above has us returning to Earth and a quick visit and landing on Mars.


I may also use it for a sci-fi short story (the ATS short story forum) expanding on the hypothetical scenario I wrote here on ATS in this forum awhile back.

You can see what the surface and even photosynthetic life would look like on planets around stars similar to and very different from out Sun. (Plant life would be different colors than our Earthly green depending on the predominant color of the light from different types of stars). - More in this PDF

a reply to: JadeStar

Thanks for your reply!

Did you visit the link? It mentions some calculations made by astrophysicist Sean Raymond that can fit up to 60 stable worlds in the habitable zones of a binary star system. It wouldn't seem very likely for such a place to occur naturally but if systems like Gliese 667 C are common, one in a billion stars out there could have a dozen Earths or more, like the rare perfectly round pearls.

About the habitable gas tori, I read somewhere that older neutron stars emit less radiation but I'm not knowledgeable about it, perhaps one of those would be better for life.

This also got me imagining that highly advanced civilizations could find it easier to engineer working with nature, building structures like a self sustaining gas torus instead of dealing with the mechanical stresses of an Alderson disk, for instance, or a solid ringworld.

And yes, exomoons are definitely missing. : )

a reply to: teslahowitzer

Perhaps under the atmospheres of highly advanced worlds there are not only cities stretching to the clouds but universes themselves, supercomputers simulating limitless universes, where are alien friends prefer to live eternally. : )

originally posted by: thyextendedself

With over 100 billion Earth-like planets now thought to exist in the Milky Way, the possibilities for worlds that escape our imagination seem now an endless reality. These are some of the fascinating, naturally occurring and physically possible habitable worlds of our galaxy, some of which writers have imagined and others which scientists have predicted:

Double habitable planets: For humans it would seem Contact is light years away but for many extraterrestrial civilizations it could be at the distance of one Apollo mission. These are stable double Earths separated by only half the diameter of each of the worlds!

On these ones the tides would be humungous. Also, when you are situated between the two planets you would weigh much less as the center of gravity would be above your head. On the far side you'd be heavier. Olympics would be real fun - long jump 1000 meters!