Since the first confirmation of an exoplanet orbiting the star 51 Pegasi in 1995, scientists have been discovering more planets outside of our solar system left and right because of advancements in technology. The most exciting confirmation yet is that of the potentially habitable planet, Proxima b, orbiting a nearby star, Proxima Centauri, and that's because it's both Earth-like and the closest exoplanet to us in the universe.
Well, if we weren't talking about an Earth-like planet, you might ask, "What makes a planet potentially habitable?" Well, in simple terms, a planet's habitability "involves being at the right distance from the host star for liquid surface water to be present, various physical and dynamical aspects of the planet, radiation type and intensity, and the host star's plasma environment." According to that definition, there's a ton of exo-planets like that out there, and most of them are super-Earths, which means that the mass and radius are bigger than our planet's.
Before the discovery of Proxima b, the closest "potentially habitable planet" was 13.8 light years away. Proxima b is only 4.2 light years away and more promising, although researchers are hoping that its location provides a possible opportunity for exploration "in the coming centuries."
Researchers don't know much about it yet, especially if there's water or even an atmosphere, but they know that it's in a habitable zone and they've made some estimations of the temperature of the surface: it may be between 86 to 104 degrees Fahrenheit (31 to 40 degrees Celsius) if it has an atmosphere, -22 to -40 degrees Fahrenheit (-30 to -40 degrees Celsius) if it doesn't.
Talk about exoplanets had simmered down but there is an increase once again because of this exciting recent discovery; and whenever there's talk about exoplanets, there's talk about the possibility of extraterrestrials.
Could there be life on this planet?
Even though the planet gets 100 times more radiation than Earth, there could be a strong magnetic field and atmosphere like the ones on Earth to block out all of the radiation to protect life at the surface.
Then there's the fact that the planet could be "tidal locked," meaning that one side is always facing the sun, but even then, there's the possibility that heat could be evenly distributed around the planet due to a present atmosphere or oceans. Before researchers came to that conclusion, once a planet was deemed to be tidal locked, that was "game over" for habitability.
Cornell University’s Jack O’Malley-James and Lisa Kaltenegger came together to find various ways extraterrestrials could survive intense UV radiation by observing organisms on Earth that do so on a lower level. In particular, they paid close attention to coral and how they convert radiation to emit longer wavelengths and "shield themselves and their co-habitating algae." Corals aren't the only ones who use UV radiation to glow (fluorescence): sea turtles, sharks, flowers, fish, and others do too but they use it for communication, not protection. Yet, these observations could give scientists hope if it turns out that magnetic fields and an atmosphere are missing from Proxima b.
Researchers usually look for Earth-like features in exoplanets to deem them habitable because of lack of resources and time, but maybe they should consider extraterrestrials that may adapt to extreme conditions when it comes to a favorable exoplanet so close to home.
