Perhaps you believe that one Earth is sufficient. But what if the number was in the billions? According to new research, the number of Earth-like planets in our Milky Way galaxy could approach 6 billion.
Astronomers at the University of British Columbia (UBC) examined data from N.A.S.A’s Kepler project and came to a startling conclusion. From 2009 to 2018, the Kepler planet-hunting satellite collected data on 200,000 stars.
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The criteria used by the scientists to select this planet included that it must be rocky, roughly the same size as Earth, and circle a star similar to the Sun. Because the conditions would be perfect for the existence of water and life, this planet had to be in the habitable region of its star.
Michelle Kunimoto, a UBC researcher who previously discovered 17 new planets (“exoplanets”) outside our Solar System, stated that their findings “set an upper limit of 0.18 Earth-like planets per G-type star.” To put it another way, there are roughly 5 planets for each Sun.
Kunimoto used a technique known as ‘forward modelling’ to undertake the study, which allowed her to overcome the problem that Earth-like planets are difficult to detect due to their tiny size and orbital distance from their star.
“I started by simulating the full population of exoplanets around the stars Kepler searched,” expounded the researcher in UBC’s press release. “I marked each planet as ‘detected’ or ‘missed’ depending on how likely it was my planet search algorithm would have found them. Then, I compared the detected planets to my actual catalogue of planets. If the simulation produced a close match, then the initial population was likely a good representation of the actual population of planets orbiting those stars.”
While the scientists came up with an astounding number of hypothetical Earths, this does not necessarily imply the number of such planets exists or whether they have life similar to ours. However, this new estimate increases the likelihood that comparable worlds exist.
Soucre: stunning.sci-nature.com
