Are we alone in the Universe? This question does not give rest to researchers of all times and peoples. Scientists repeatedly put forward various theories about how exactly alien life can give out its presence on a given exoplanet. Reflecting on this, researchers from Cornell University put forward his very original theory.
Why some organisms are able to glow?
Almost every one of us saw the fireflies and knows that these tiny creatures are able to glow in the dark. In addition, fluorescence can not only certain insects but also fish, squid, bacteria and many other creatures. They do this for various reasons, which include the involvement of partners, camouflage, lure prey and marking territory.
In nature, there is another type of luminescence called “sunscreen biofluorescence”. Such a method of light irradiation is a kind of defense mechanism found in certain types of underwater corals that live at depths sufficient for the ultraviolet radiation from the Sun. Usually this radiation is absorbed by the tissues of the coral, which leads to unpleasant and possibly deadly “sea tan”, however deep the polyps were not all that simple as we might think.
The fact that sly corals invented method of protection from harmful radiation of the Sun. In other words, biofluorescence proteins in the tissues of the coral absorb UV light, exciting an electron and raising it to an unstable energy state. When an electron returns to its stable state, it re-emits radiation in the visible band of the light spectrum. As a result of UV radiation becomes harmless, and the animal fluoresces.
Researchers from Cornell believe that such a mechanism could be useful for any extraterrestrial life that evolved in the most pleasant environment, for example, in the habitable zone of stars, M-type, where was found a large number of exoplanets.
Can planets emit light?
Imagine little red star is M-class, the constantly exploding harmful ultraviolet flashes. This unstable dwarf can support life on their planets-the satellites only if the latter has a dense atmosphere, one way or another to protect the local flora and fauna. But even assuming the availability of life-saving shell around the planet, harmful UV light can seriously damage the existing life there.
However, if the living alien organisms used biofluorescence for their protection, it not only would give them a fighting chance with the unpleasant consequences of ultraviolet radiation, but also would create a special biosignal, which could be detected by telescopes.
To test this hypothesis, a team of scientists from Cornell have studied the spectral radiation of a conventional fluorescent coral and used them to obtain model spectra and colors, which can be found on exoplanets orbiting stars M-type. They came to the conclusion that the strength of the illumination may be sufficient for detection by telescopes that are currently under development.