Extraterrestrial life might be living close to Earth on the newly-discovered planet Barnard b, if that planet turns out to be rocky, new research suggests. However, the frigid conditions on this alien world suggests such life would likely be primitive, as it was for the majority of the history of the Earth.
Barnard b (otherwise known as GJ 699 b) is a super-Earth, roughly three times larger than our own world. If this planet is rocky, like the Earth or Venus, it might have a molten core, providing a heat source capable of melting ice on the surface, creating regions of liquid water.
“Geothermal heating could support “life zones” under its surface, akin to subsurface lakes found in Antarctica. We note that the surface temperature on Jupiter’s icy moon Europa is similar to Barnard b but, because of tidal heating, Europa probably has liquid oceans under its icy surface,” Edward Guinan, astrophysicist at Villanova University said.
Barnard’s Star, roughly nine billion years old, is the closest single star to the Earth, sitting just 6 light years from our home planet. The Alpha Centauri system is closer, but there are two stars in close proximity there, with a third star further out.
The planet Barnard b revolves around the red dwarf star at about the same distance as Mercury maintains from the Sun, once every 233 days. This places it in the “snow line” where frozen water could exist on its surface. Estimates place the average surface temperature of Barnard b at around -170 degrees Celsius (-274 Fahrenheit).
If Barnard b is a rocky world, possessing a molten core, then there is a chance that life may have formed — and possibly even still exist — on that planet. However, if it turns out to be a gaseous body, similar to smaller versions of Uranus or Neptune, the chances of finding life there diminish greatly.
Europa, the fourth-largest Moon of Jupiter, has a temperature and icy surface similar to that which might be found on Barnard b. On that moon, the presence of powerful radiation from Jupiter, as well as tidal forces, warms the satellite, spawning subsurface oceans. This makes Europa one of the leading candidates for places we may, one day, find alien life in our own solar system. Here on Earth, similar lakes are found under the ice of Antarctica, heated by thermal energy from the core of the Earth. The largest of these, Lake Vostok, is roughly the size of Lake Ontario, and researchers believe it may harbor life cut off from the rest of the world for 15 million years.
A molten core within Barnard b could also protect the planet from radiation emanating from its parent star, allowing an atmosphere to develop and not be cast out into space. That star, like all red dwarfs, is becoming less active as it grows older, while the planet slowly spirals away from the star due to tidal forces. This suggests Barnard b may have been warmer in the past than it is now, perhaps once possessing oceans of liquid water on its surface.
Barnard b cannot be seen by the current generation of telescopes, but it might be visible to astronomers using the James Webb Space Telescope, currently scheduled for launch in March 2021. Future instruments may be able to directly measure any telltale signs of life on the distant planet.