At the darkest moment comes the light
In recent years, the search for an Earth-like planet orbiting another star has been the most exciting in science. The world has waited with baited breath for the discovery of another Earth.
But the discovery of Earth 2.0 has been a damp squib. Not because astronomers haven’t found one; on the contrary! The problem is they’ve found too many candidates. And these have turned out to be so unlike Earth that it’s hard to imagine that any of them can be a convincing twin.
We’re left, like the starving donkey equidistant between two bails of hay, unable to decide on what to celebrate.
The top candidates so far are these:
* Gliese 4581 g, the fourth rock from a red dwarf some 20 light years from Earth in the constellation of Libra
* GJ 1214 b, a sub-Neptune-sized planet orbiting a star in the constellation of Ophiucus 40 light years away
* and HD 28185 b, a gas giant in a near circular orbit that is entirely within the habitable zone of a Sun-like star in the constellation of Eridanus. This planet’s moons, if it has any, may be good candidates for ‘other Earths’
Today, we can add another strange planet to the list: 55 Cancri f, one of five planets known to orbit an orange dwarf star some 40 light years away in the constellation of Cancer.
