A free-floating planet is generating some out-of-this-world buzz.
While most planets orbit a host star, like the Earth revolves around the sun, an international team of scientists recently spotted a planet without a star. The extrasolar planet, dubbed PSO J318.5-22, appears to be drifting through space.
"We have never before seen an object free-floating in space that looks like this," team leader Dr. Michael Liu, of the Institute for Astronomy at the University of Hawaii at Manoa, said in a written statement Wednesday. "It has all the characteristics of young planets found around other stars, but it is drifting out there all alone. I had often wondered if such solitary objects exist, and now we know they do."
Astronomers stumbled upon the strange world two years ago while using the Pan-STARRS 1 survey telescope to look for brown dwarfs, often called "failed stars." The scientists then conducted follow-up studies with other telescopes to learn more about the sunless planet.
A multicolor image from the Pan-STARRS1 telescope shows free-floating planet PSO J318.5-22 in the constellation of Capricornus. (Image credit: N. Metcalfe & Pan-STARRS 1 Science Consortium)
PSO J318.5-22 is about 80 light-years from Earth and is estimated to be only about 12 million years old. Our solar system is estimated to be 4.5 billion years old, while the oldest star known to exist in the universe is estimated to be about 13.2 billion years old.
Since the free-floating planet has properties similar to gas giants like Jupiter, Liu hopes that examining it at such a young age will yield insights into the "inner workings" of these these unusual celestial bodies.
"I'm very optimistic that we will find several more of these in the next couple years," Liu told the Hawaii Tribune Herald.
The astronomers submitted their research to the peer-reviewed Astrophysical Journal Letters last week.