A new planet with the potential of sustaining life was discovered by astronomers at Queen Mary University Of London orbiting Proxima Centauri, the nearest star to the Sun – 4.2 light years away. Using small wobbles in the trajectory of Proxima Centauri caused by the orbit of this planet, dubbed ‘Proxima b,’ the astronomers calculated that the planet is one third more massive than earth, and orbits the star once every 11.2 days, or about 1/32 of an Earth year.
Proxima b exists in the ‘Goldilocks Zone’ of its parent star. If a planet is too close to a star, any liquid water evaporates. Likewise, planets that are too far find all of their water locked up in ice. In the middle sweet spot is where liquid water – and potential life – can exist. Other factors, including that star’s lifecycle and the atmospheric composition of the planet, must also fall into place to sustain life.
The most exciting part about Proxima b, however, is that it is so close (relatively speaking.) The next generation of telescopes may be able to observe thermal emissions from the planet, and further advances may one day allow characterization of the planet’s atmosphere, see ‘ocean glint’ as an indication of liquid water, or even detect biological signatures in the atmosphere. Life on Proxima b is anything but a certainty, but the opportunity to look for signs of extraterrestrial life within our lifetimes is truly exciting.
Acknowledgments: Many thanks to Dr. Giada Arney, a postdoctoral fellow at NASA Goddard Space Flight Center, for her insight and comments on the story.
Managing Correspondent: Sam Dillavou