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How many Earth-like planets are around sun-like stars?
- Strilanc 7y agohttps://iopscience.iop.org/article/10.3847/1538-3881/ab31ab https://iopscience.iop.org/article/10.3847/1538-3881/ab31ab > For planets with sizes 0.75–1.5 R ⊕ and orbital periods of 237–500 days, we find a rate of planets per FGK star of <0.27 (84.13th percentile). While the true rate of such planets could be lower by a factor of ~2 (primarily due to potential contamination of planet candidates by false alarms), the upper limits on the occurrence rate of such planets are robust to ~10%.
- z3t4 7y agoWhat's interesting is that we can only see things that are as big and bright as a star, and the occasional planetoid that happens to pass by exactly between us and the star. There are very likely a lot more stuff in the universe.
- xt00 7y agoTLDR: 1 in 4 stars, but there are some big error bounds. "Based on their simulations, the researchers estimate that planets very close to Earth in size, from three-quarters to one-and-a-half times the size of earth, with orbital periods ranging from 237 to 500 days, occur around approximately one in four stars. Importantly, their model quantifies the uncertainty in that estimate. They recommend that future planet-finding missions plan for a true rate that ranges from as low about one planet for every 33 stars to as high as nearly one planet for every two stars."
- cryptoz 7y agoIt's incredible. That would be, from ~250B stars in the milky way to ~62B Earth-like planets in our galaxy alone. Assuming even distribution across the whole universe, that's 1,000,000,000,000,000,000,000 stars *.25 = 2.5e+20 Earth-like planets in the universe. Astonishing estimates. As an aside, this Google search result is alarmingly wrong. I wonder how often Google is this wrong for things like medical queries? Yikes. https://imgur.com/a/v75P575 https://imgur.com/a/v75P575
- jobigoud 7y agoThe research in the OP is only for stars that are like the Sun.