The Milky Way may be teeming with planets with oceans and continents like here on Earth

Astronomers have long looked into the vast universe in hopes of discovering alien civilizations. But for a planet to live, liquid water must be present. The likelihood of that find scenario seemed impossible to calculate because planets like Earth are believed to get their water by chance when a large ice asteroid hits the planet.

Now, researchers from the GLOBE Institute at the University of Copenhagen have published an eye-opening study, which indicates that water may be present during the formation of a planet. According to the calculations of the research, this applies to Earth, Venus and Mars.

All of our data suggests that water was part of the earth’s building blocks from the start. And because the water molecule is common, there is a reasonable chance that it applies to all planets in the Milky Way. The decisive point of whether liquid water is present is the planet’s distance from its star, ‘said Professor Anders Johansen of the Center for Star and Planet Formation, who led the study 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 they were millimeter-sized particles of ice and carbon – known to orbit all of the young stars in the Milky Way – that intertwined 4.5 billion years ago to form what would later become Earth.

“To the point where the Earth had grown to one percent of its present mass, our planet grew by capturing masses of pebbles filled with ice and carbon. The Earth then 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 rose sharply, causing the ice in the pebbles to evaporate on its way to the surface, so that today only 0.1 percent of the planet is made up of water, although 70 percent of the earth is made up of water. the surface is covered with water, ”says Anders Johansen, who ten years ago together with his research team in Lund put forward the theory that now confirms the new study.

The theory, called “pebble growth,” is that planets are formed by pebbles that clump together, and the planets get bigger and bigger.

Anders Johansen explains that the water molecule H2O is found all over our galaxy, and that the theory therefore opens the possibility that other planets were formed in the same way as Earth, Mars and Venus.

All the planets in the Milky Way can be formed by the same building blocks, which means that planets with the same amount of water and carbon as Earth – and thus potential places where life may be present – often occur around other stars in our galaxy, provided the temperature is good ‘, he says.

If planets in our galaxy have the same building blocks and the same temperature conditions as Earth, there is also a good chance that they have about the same amount of water and the same continents as our planet.

Professor Martin Bizzarro, co-author of the study, says:

‘With our model, all planets get the same amount of water, and this suggests that other planets not only have the same amount of water and oceans, but also as many continents as here on Earth. It offers good opportunities for life to emerge, ”he says.

If, on the other hand, was arbitrary how much water was present on planets, the planets could look very different. Some planets would be too dry to develop life, while others would be completely submerged.

“A planet covered in water would, of course, be good for marine creatures, but would not provide ideal conditions for the formation of civilizations that can observe the universe,” says Anders Johansen.

Anders Johansen and his research team are looking forward to the next generation of space telescopes, which will provide much better opportunities to observe exoplanets orbiting a star other than the sun.

‘The new telescopes are powerful. They use spectroscopy, which means you can see how much water vapor there is by looking at what type of light is being blocked in the orbit of the planets around their star. It could tell us something about the number of oceans on that planet, ”he says.