Our nearest Earth-like planet
Is there life on the closest planet to our Solar System? That's what astronomers will be hoping to answer soon by studying Proxima b in detail. It orbits the star Proxima Centauri, just 4.2-light-years away, and the closest star to our Sun. If the planet is habitable, it might well be possible to detect life on its surface.
The discovery of Proxima b was announced in 2016, and since then scientists have debated whether it might be habitable. The planet is 1.3times the size of Earth and orbits its star at a distance of just 5 per cent of Earth's orbit around the Sun. But, because its parent star is a much dimmer red dwarf, Proxima b might be in the habitable zone of its star.
There's a lot we don't know about red dwarfs, though. They might be more prone to solar flares, which could make life on Proxima b tricky. We also don't know if they actually supply enough energy to the planet for it to sustain life. If it does, we might be able to see signs of life by studying the planet's atmosphere.
We could do this by noticing the flash of aurora as the star's particles hit the planet. The colour of aurora produced would tell us what gases are in its atmosphere. Oxygen, for example, is partly responsible for the green glow of our own aurora. A direct detection of life here, though, might be tricky.