There are hundreds of millions of worlds in the Milky Way where life could exist - study
In our Milky Way galaxy, there are hundreds of millions of planets that may be well suited to support life. We are talking about star systems with so-called red dwarfs shining in their centre, which are much smaller than our Sun.
This is stated in a study published in the journal Proceedings of the National Academy of Sciences. The study was authored by Professor of Astronomy Sarah Ballard and doctoral student Sheila Sagira from the University of Florida.
As the scientists explain, the Sun observed by earthlings is a G-type star - such stars are unofficially called yellow dwarfs. Despite the fact that the Sun is so familiar to us, such stars are quite rare within the Milky Way galaxy, as the most common are M-type stars. These are red dwarfs that are much smaller and colder and have half the mass of our Sun.
It is around such stars that billions of planets in our galaxy orbit.
Ballard and Sagir used data from NASA's Kepler telescope and ESA's Gaia telescope to study 163 exoplanets orbiting red dwarfs.
They found that in order to get enough heat, planets in such systems have to be very close to their stars. In certain cases, this leads to the fact that the planets are simply fried, but there are better scenarios.
Scientists estimate that two-thirds of exoplanets will be too close to the star to be in the safe zone, but one-third will fall into the zone that is quite suitable for preserving water on the planet and the formation of life.
Yes, this forecast may sound rather pessimistic, but in absolute terms, it means that hundreds of millions of planets orbiting red dwarfs in our own galaxy may have life, or at least the conditions for its future emergence.
"I think this result is very important for the next decade of exoplanet research because the focus is shifting towards this population of stars," Sagar explained.
In her opinion, red dwarfs should become targets for the search for small planets in their orbit. After all, this will be the easiest and most accurate way to detect a planet that is likely to have water in a liquid state, and "therefore, the planet may be habitable."
Sagir and Ballard also found that stars with multiple planets are more likely to have circular orbits, which allow the planets to hold liquid water. Stars with a single planet will have extreme tides, leading to overheating of the planet and evaporation of water.
Earlier, OBOZREVATEL also reported that scientists have discovered a process in the atmosphere of an exoplanet that has never been seen outside the solar system.