In just the past five years or so, a bevy of rocky, Earth-like exoplanets have popped up on astronomers’ radar. But for a lot of these planets, the similarities with Earth end at rocky. Furthermore, many of them orbit red dwarf stars. These stars, while smaller and cooler than the Sun, are notoriously ill-tempered. They often throw tantrums, soaking their planets in radiation that would put an end to most Earth life.
But there is a species of coral that converts harmful radiation from the Sun into beautiful green and blue biofluorescence. Inspired by this wonder of nature, a team of astronomers has posited that life on other planets might do the same, as Popular Science reports.
If they’re right, planets with this type of life might light up like Christmas trees when their red dwarf stars flare up. This light could possibly make it into the lenses of future telescopes. Take for instance, the Extremely Large Telescope in Chile set to go online in 2025. “Imagine how it would look,” Lisa Kaltenegger, a researcher at Cornell University and proposal coauthor said. “It’s something that’s really beautiful to think about.”
The thought does leave a stunning image in the mind’s eye. But which planets might actually host this type of biofluorescent life and are close enough that telescopes could pick it up? Life as we know it needs water to exist. So the planet would have to orbit in the so-called Goldilocks zone where liquid water can exist on the surface.
Proxima b is a possible contender. It orbits Proxima Centauri, the closest star to our solar system at just four light-years away. Proxima b is also in the habitable zone and close enough for future astronomers to possibly catch a glimpse of biofluorescent life if it exists there. At 39 light-years away, the Trappist system boasts seven rocky planets. A few of these sit in the Goldilocks zone of their star Trappist-1.
Keeping an Open Mind
But could life really exist on any of these worlds? Just because they’re in the habitable zone isn’t a guarantee that life could take hold. Both Proxima Centauri and Trappist-1 are volatile red dwarf stars. Life on Earth had the luxury of evolving with the protection of the ozone layer. As far as astronomers know, none of these planets have such a protective atmosphere or any atmosphere at all.
As Popular Science pointed out, biofluorescent life on these planets rests on a pile of “ifs:” if the planet is in the habitable zone, if the planet has a protective atmosphere, if life could form, and if that life has evolved to fluoresce. However, just because these “ifs” don’t add up, doesn’t mean that life can’t “find a way” as Jeff Goldblum’s character in Jurassic Park famously pointed out.
Kaltenegger is keeping her mind open. “This [research] is just us trying to make sure we don’t have blinders on, that we use the diversity that we know of here on the Earth to look for life somewhere else.”