According to researchers at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), there may be a multitude of planets wandering the Milky Way Galaxy outside the orbit of any star. Researchers estimated that there may be 100,000 times as many of these nomad planets as stars in the galaxy.

The estimates were obtained by factoring in the Milky Way’s gravitational pull, the amount of available matter to compose the planets and the potential of said matter to form planets of varying sizes.

“If any of these nomad planets are big enough to have a thick atmosphere, they could have trapped enough heat for bacterial life to exist,” said Louis Strigari in the Stanford Report. Strigari led the research team at KIPAC, which is a joint institute of the SLAC National Accelerator Laboratory and Stanford University.

According to the research paper submitted by the team to the Monthly Notices of the Royal Astronomical Society, the heat necessary for life to exist on these planets could come from internal radioactive decay as well as surface tectonic movement.

Researchers first identified nomad planets last year using gravitational micro-lensing, a procedure that detects stars whose light has been distorted momentarily by the gravitational pull of nearby planets.

The study raised questions regarding planet formation and the potential for nomad planets to support life. Researchers outside of Stanford expressed enthusiasm for the new findings.

“To paraphrase Dorothy from “The Wizard of Oz,” if correct, this extrapolation implies that we are not in Kansas anymore, and in fact, we never were in Kansas,” said Alan Boss of the Carnegie Institution for Science, according to the Stanford Report.

— Judith Pelpola