In an effort to spot a cellular life form on another planet, researchers come up with a surprising idea. Scientists want to use the shade of trees. The hypothesis is still young, but it has the merit of exploring an interesting track.
In August 2020, the TESS satellite completed its two-year primary mission with several significant discoveries to its credit. The latter is responsible for two-thirds of the discovery of more than 4,200 exoplanets made to date. Nevertheless, despite the number of planets detected, scientists have yet to spot any extraterrestrial life forms. In a publication in the International Journal of Astrobiology on October 1, 2020, researchers from Northern Arizona University (USA) come up with a rather amazing research method. According to them, we should be interested in trees, or rather in their shade.
The study leaders say they have placed their interest in one life form in particular. It is about vertical photosynthetic multicellular life abundant, coming from the trees. This life would cast shadows at significant solar angles, angles that will distinguish it from "classic" single-celled life.
US scientists are testing their method by pretending the Earth is an exoplanet. On Earth, there are about 3 trillion trees . Everyone has their own shadow, different from the one that inert objects cast on the ground. In any case, the idea is based on the following hypothesis:the multicellular life most likely to be present in abundance would be vertical photosynthetic organisms.
As for the shadows obtained via the solar angles, this has not yet been proven. If necessary, it will be necessary to be able to detect them on the exoplanet. The fact is that the next telescopes that will observe the sky will probably not have much headroom. However, according to scientists, these will only have a single pixel on the images to determine whether life is present or not.
The large-scale tests required the use of data from the CNES Polder instrument. The goal? Analyze clouds and aerosols and observe the shade of trees on Earth at different times of the day. The definition of the trees has been reduced to one pixel in order to represent what an observer would see contemplating the Earth revolving around the Sun. The method allows researchers to distinguish multicellular life through shadows. On the other hand, when the planet is reduced to one pixel, this becomes very complicated.
For researchers, it is important not to abandon this trail. According to them, this one could still work but needs more research so that it can be used with confidence. This study has at least the merit of highlighting the potential of trees and their shadows for the search for extraterrestrial life.
In the more or less near future, future telescopes could observe planets with more pixels. In other words, these technological advances could possibly give more credit to this method.
