So, the boys at NASA Ames in Mountain View, California, have found a planet, which is Earth-sized, and on the cool edge of the “Goldilocks” region of the system: the region at which liquid water, if it exists, can be found. The planet, Kepler-186f, as it is fondly known, orbits a class-M dwarf (Red Dwarf) star in the Cygnus (The Swan) constellation, about 500 light years from us.
The thing that has caught the attention of NASA is that it is the first Earth-sized planet to be found in the Goldilocks zone, and although nothing is known yet about the planet’s composition or mass, yet, if it proves to be of Earth-type mass, then it will be big enough to hold its own atmosphere. If Earth conditions were replicated then it would be rather chilly, with the sun at midday, only being equivalent to an hour before sunset here … so exactly the same as mid-summer in Wales! Joking aside, we don’t yet know if 186f has an atmosphere, or what its composition is, if it has one.
Though the planet is potentially habitable, at a distance of 500 light years, Kepler-186f, is out of reach of the human race, with its current technology. At present achievable speeds, (Voyager I reached velocity of 38,000 mph) and an unhindered passage, an Earth ship would take 886,000 years to get there.
When you look at how we behave in close quarters, it is doubtful whether present-day humans could get there sociologically, never mind technologically.
The SETI (Search for Extra Terrestrial Intelligence) organization is involved with the Kepler adventure, and the search for ET at home goes on.
To be of real use to the human race, an exo-planet would have to be very close to Earth (less than ten light years), lower on the evolutionary scale (no intelligent life forms), capable of supporting or having vegetation (for renewable oxygen), and myriad other favorable conditions. In addition, Earth energy supplies would have to be a fraction of current prices, to even begin considering colonizing.
So, it seems that even if Kepler-186f were a mirror copy of Earth, our chances of getting there are, with current tech, vanishingly small, and we have no way of enjoying it, but from afar. Still, it stirs the imagination to think of the future possibilities.