Astronomers Detect Earth-Sized Rogue Planet
RandomFactor writes:
Astronomers have used microlensing to detect an approximately Earth-mass planet wandering between the stars.
Finding something in deep space that emits no light of its own is extremely challenging. But two organizations are doing just that. They're the OGLE (Optical Gravitational Lensing Experiment) collaboration and the KMTN (Korean Microlensing Telescope Network) collaboration.
Now, a team of scientists from both groups have announced the discovery of a low-mass rogue planet. There are no stars near it, and its distance from Earth is unconfirmed.
The team says it proves that the microlensing technique is effective at finding Earth-mass planets that are free-floating in space.
The paper announcing the discovery has 30 authors.
A relatively tiny object like a low-mass planet doesn't bend much light, and not for too long, either. In their paper the authors say "Microlensing events due to terrestrial-mass rogue planets are expected to have extremely small angular Einstein radii (.1 as) and extremely short timescales (0.1 day)." According to the authors, this is the "most extreme short-timescale microlens discovered to date."
Estimates for the number of rogue planets wandering our galaxy range between "a few billion and a trillion."
Read more of this story at SoylentNews.