5
votes
2answers
105 views

Galactic Habitable Zone

Do galaxies have habitable zones the same as stars do? Say in a galaxy with a very active nucleus producing a lot of heat and radiation, would there be a point at which no star's planets could harbor ...
4
votes
1answer
112 views

What is the maximum number of planets in the habitable zone?

At present, it seems like we are alone in our solar system. How many earth-like planets would fit into the habitable zone of the solar system? The orbits should be stable for quite a time, i.e. for ...
5
votes
1answer
49 views

Could there be Earth-like planets in binary or trinary systems?

Could Earth-like (suitable for Human habitation) planets exist in systems with 2 or 3 suns, have any been found? With more than a single star, isn't it likely that the habitation zone would be too ...