There are stars more favorable to life than the Sun!

Photosynthesis is this mechanism which allows oxygen to be synthesized from light. It first occurred on Earth among the cyanobacteria2.45 billion years ago, and without it we wouldn't be here. We wouldn't be here at all. It's fascinating to realize that 100% of the energy that powers our bodies comes, in one way or another, from the light and heat of the Sun.

As The Digitals echoed it yesterdaythe search for extraterrestrial life is a very active field of astronomy. Indeed, the question of whether terrestrial biological processes have equivalents elsewhere is crucial; it is even one of the biggest scientific questions of the 21st century. And precisely, this discovery gives even more credence to the hypothesis that life may be relatively common in the Universe!

We only know of our existence, so it is tempting for scientists to look in the Universe for the same conditions as those prevailing on Earth in our solar system, that is, a rocky planet orbiting a G-type star, like the Sun. However, there are many other types of stars, more or less hot and more or less large than our neighboring star. Their color betrays their temperaturefrom red for the least hot to blue for the hottest.

The star in question is an orange dwarf (type K), slightly less massive and hot than the Sun. The experiment was carried out as follows: the researchers placed a very common plant under lights simulating that of the Sun, of an orange dwarf, but also without light. The results speak for themselves:

Orange dwarfs are more common than solar-type stars, and they are seven times longer-lived! While the Sun has about 10 billion years of life expectancy before exhausting its fuel, an orange dwarf, with a more modest hydrogen consumption, lasts 70 billion years before reaching the end of its life, or about five times the current age of the Universe! Life would therefore have every “interest” in developing there, if we can put it that way.

Where the experiment really reshuffles the cards is that it also shows that the evolution of cyanobacteria, to whom we owe the oxygenation of the atmosphere billions of years ago, is just as satisfactory with orange dwarfs as with yellow dwarfs! Life similar to ours, that is to say based on carbon and breathing dioxygen could thus quite easily develop and prosper even better under these orange stars.