Researchers at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), a joint institute of Stanford University and the SLAC National Accelerator Laboratory, estimate that there are 100,000 times more of these planets than stars in the Milky Way. The study was published in the Monthly Notices of Britain’s Royal Astronomical Society on Thursday.

The researchers said that these free-floating planets may have been ejected from their original parent stars and could be accompanied by flocks of moons, the San Francisco Chronicle reported.

My blog has been a little slow lately, and here's why: I've just started an editorial internship at Sky & Telescope!  Now I finally get to do for a living what I've been doing for fun for the past few years, which is pretty darn awesome.  But combine a new job with a four-month old adorable baby boy, and there won't be much blogging going on here for a little while.

By Irene Klotz, Discovery News, Feb 24, 2012 The Milky Way may be teeming with more than 100,000 free-flying planets for every star--these are worlds that unlike our orderly solar system are not orbiting parent stars.

This is the finding from a study that extrapolates from observations of a dozen so-called "nomad" planets, which were detected when their gravity briefly contorted light of passing stars--a phenomenon known as gravitational microlensing.

To derive the estimate, astrophysicist Louis Strigari, with Stanford University's Kavli Institute, and colleagues factored in the gravitational pull of the Milky Way, how much material it contains and how that material might be divided up among bodies ranging from Jupiter-sized objects down to tiny worlds like Pluto.

Among the study's most interesting conclusions is that that there are not enough solar systems in the galaxy to account for all the nomad planets, which means that not all the free-flying worlds are orphan planets ejected from their birthplace.