The second exoplanet closer to our solar system may seem like a cold, alien and inhospitable place, but if it were not? And if, as new research suggests, there are pockets of habitable environments deep beneath its icy surface, supposing it can produce heat from its core?
Discovered at the end of 2018, Barnard & # 39; s Star b is like none of the planets in the solar system. With a mass three times greater than that of the Earth, this enigmatic exoplanet is known as a "super-Earth," a probable rock planet occupying a mass gap between the Earth and the smaller gaseous giants, such as Neptune. Exoplanet hunting missions like Kepler found that super-lands are common throughout the galaxy, so Barnard's star b is more than just a curiosity, it could become the key to understanding how they were formed, what they are facts and the most conspicuous, because the solar system does not have one.
After a scrupulous search through two decades of Spectroscopic data from the Star of Barnard, astronomers announced the discovery of the new world in November. They found a 233-day "swing" that indicated that an extrasolar planet was about the same distance as Mercury orbits around our sun, pulling the star slightly as it orbits. But, since the star is a low-mass, dim red dwarf, the planet's orbit places it beyond the "habitable zone" of the star and its "snowline". If Barnard & # 39; s Star b has water on its surface, it will be frozen and does not favor life support (as we know it).
However, according to new research presented at the 233th meeting of the American Astronomy Society (AAS) in Seattle, Washington, on January 1
"Geothermal heating could support" areas of life "beneath its surface, similar to the underground lakes found in Antarctica," said in a statement the astrophysicist Edward Guinan, of the University of Villanova. "We note that the surface temperature on the frozen moon of Jupiter Europe is similar to Barnard b but, due to the warming of the tides, Europe probably has liquid oceans beneath its icy surface."
Astrobiologists have been to long fascinated by Europe.Although it orbits Jupiter well beyond the habitable zone of our sun and has a very obvious ice crust, through tidal interactions with the gaseous giant, its core produces heat that keeps a subsurface ocean in. a state of liquid water Decades of moon observations have also revealed that the ocean can have sufficient amounts of oxygen and nutrients to support a hypothetical or marine ecosystem.
Barnard's star b is much larger than Europe and may not have the same degree as The Moon of Jupiter, but it should have a large, hot iron / nickel core, Guinan and his co-investigators suspect his geothermal activity can nourish primitive forms of life.
Alas, we are surpassing ourselves. Barnard & # 39; s Star b could be habitable, but currently only knows its mass and the orbital period around the star. We know nothing of its composition, atmosphere (if it has even one) or physical dimension. It will undoubtedly be cold, since the star generates only 0.4 percent of the radiant power of our sun, but does it have frozen water? Does it have geothermal activity? For now, we do not know, but there is hope.
Barnard's star is only six light years from Earth, so it is conceivable that a future generation of powerful telescopes will have the power to observe the alien world. According to the researchers, these observations will shed light on the nature of the planet's atmosphere, on the surface and on potential habitability.
"The most significant aspect of the discovery of the star b from Barnard is that the two star systems closest to the sun are now known to house the planets," Engle said in the same statement. "This supports previous studies based on Kepler's mission data, deducing that planets can be very common across the galaxy, tens of billions."
The closest exoplanet to the Earth is Proxima Centauri b, a world of earthly dimensions that orbits around its red dwarf star inside the habitable zone, the distance surrounding a star that could allow a planet to possess liquid water on its surface. On paper, this seems like a fantastic place to look for alien life, but Proxima Centauri is an angry little star, known for its violent rockets that radiate any planet that orbits too close. Barnard's Star b orbits its most distant red dwarf and, if life can find a way beneath its surface, it could be protected from any ionizing radiation.