Astronomers have long been looking into the vast universe in hopes of discovering alien civilisations. But for a planet to have life, liquid water must be present. The likelihood of that scenario has seemed impossible to calculate because it has been the assumption that planets like Earth got their water by chance when a large ice asteroid hit the planet.
Now, researchers from the GLOBE Institute at the University of Copenhagen have published an eye-opening study, indicating that water may be present during the very formation of a planet. According to the study’s calculations, this is true for both Earth, Venus and Mars.
“All our data suggest that water was part of Earth’s building blocks, right from the beginning. And because the water molecule is frequently occurring, there is a reasonable probability that it applies to all planets in the Milky Way. The decisive point for whether liquid water is present is the distance of the planet from its star,” says Professor Anders Johansen from the Centre for Star and Planet Formation who has led the study that is published in the journal Science Advances.
Using a computer model, Anders Johansen and his team have calculated how quickly planets are formed, and from which building blocks. The study indicates that it was millimeter-sized dust particles of ice and carbon—which are known to orbit around all young stars in the Milky Way—that 4.5 billion years ago accreted in the formation of what would later become Earth.