Finding An Earth-Like Planet
Is there a planet identical to ours somewhere in the Milky Way?
It’s perhaps of little wonder that with our own planetary biases, much of our search for exoplanets has hinged on the search for worlds similar to Earth in both composition and location in the habitable zone of their main sequence stars. Another condition that would make a world similar to Earth would be a magnetic field, which can prevent an atmosphere from being stripped away and thus sustain life.
Several of the planets in the exoplanet catalogue are similar to Earth in a range of ways, be it distance from their star, their mass or their radius. Below are 21 candidates for Earth-analogue worlds. But even if these worlds do fit the description of a ‘planet B’ that could be occupied by humans in the future, crewed travel to worlds outside the Solar System is thus far unfeasible to say the least, and likely will be for several generations. As Institute for Research on Exoplanets scientist Romain Allart points out, that means despite the wealth of exoplanets discovered, protecting our own world is still of paramount importance.