Empty Spaces

An intriguing article that came out at the start of December 2014, the new phenomenon of "MirageEarths". Following the viability of colonising Goldilocks planets, this University of Washington (Rodrigo Luger and Rory Barnes) looked at planets orbiting dwarf stars that appear habitable, but closer inspection was surprising.

It was previously believed dim stars could host water and therefore (theoretically) life. The conclusions of the study indicate that due to the time-lag in solar-activity and planet formation, after 10bn the planets are exposed to the full intensity of early-sun brightness and radiation, boiling any water to leave an apparently hospitable-atmosphere.

M dwarf stars, which include red dwarfs, are the most abundant star in our galaxy, making up three out of every four stars. However they are only about 20 per cent as massive as the sun, and thus have much smaller habitable zones (illustration shown) than other types of star.

In theory, Red Dwarfs, or M stars, (prevalent in our galaxy) potentially could host life. Due to the time it takes for these stars to form (longer collapse from gas-cloud due to lower mass & gravity), the lag means planets are exposed to the fury of early-activity, any water present would boil in the extreme temperatures to create atmospheres seemingly full of oxygen, but in reality on the surface would be dry and desolate – hence the moniker “Mirage Earth”. Oceans boil and the atmosphere is steam. 

 

              A conceptual interpretation of how the surface of such a planet would look. Any water

              will have boiled away, leaving an atmosphere (mirage) that dupes us, but on arrival 

              shows a barren environment.

As they are the most abundant star in our galaxy (therefore closest) these would present our best options for “plan Z” (last hope), as we inconveniently do not have a wormhole to escape through like Interstellar. 

A few years ago it was thought that red dwarf stars (illustrated), just a fifth as massive as the sun, were too weak to be able to host habitable planets. But more recently scientists had begun to postulate that they might be able to cling onto tight habitable zones, where temperatures are just right for water to form on a planet.

They stressed it is still possible to find habitable planets around M Dwarfs, but this does make our chances slimmer for finding a new home.