Astronomers have long investigated the vast universe in hopes of discovering extraterrestrial civilizations. But for a planet to have life, at least, as we know it, there must be liquid water. So impossible is it? The truth is that it is somewhat complicated to calculate.
Now, a team of researchers from the GLOBE Institute at the University of Copenhagen has published a study indicating that this precious liquid element could be present during the very formation of a planet. Something that, according to the study’s calculations, is true for both Earth, Venus and Mars.
“All our data suggest that water was one of the building blocks of the Earth, from the beginning. And because the water molecule occurs frequently, there is a reasonable probability that it applies to all planets in the Milky Way. The decisive point to determine if the liquid water is present is the distance from the planet to its star “, comments Anders Johansen who has led the study published in the journal Science Advances.
Using a computer model, Johansen and his team calculated how quickly planets form and from which building blocks. They calculated that Earth, Venus, and Mars were made through a process called “pebble accretion,” in which millimeter-sized particles of dust and ice coalesce into planets. Their results are therefore revealing: they indicate that 4.5 billion years ago, millimeter-sized particles of ice and carbon dust (known to orbit all young stars in the Milky Way) accumulated in the formation of what would later become Earth.
“Up to the point where the Earth had grown to 1% of its current mass, our planet developed by capturing masses of pebbles filled with ice and carbon. So the Earth grew faster and faster until, after five million years, it became as large as we know it today. Along the way, the temperature at the surface increased sharply , causing the ice from the pebbles to evaporate on the way to the surface, so that today only 0.1% of the planet is made up of water, although 70% of the earth’s surface is covered by water ”, clarifies Johansen.
Less strange than previously thought
This theory does not require that water reach a planet from the outside, but what determines the presence of liquid water on the planet is how far it is from its star. It also increases the probability that liquid water will form on other planets in our galaxy, since they could have formed in the same way from the same materials. This, in turn, increases the possibility that these planets harbor extraterrestrial life.
“All the planets in the Milky Way can be made up of the same building blocks, which means that planets with the same amount of water and carbon as Earth, and therefore potential places where life might exist, occur with frequency around other stars in our galaxy, as long as the temperature is adequate ”, continues the expert.
It seems that we have found a good opportunity for the emergence of life.
Referencia: Anders Johansen et al, A pebble accretion model for the formation of the terrestrial planets in the Solar System, Science Advances (2021). DOI: 10.1126/sciadv.abc0444
