How Many Unbound Planets in Milky Way?

Sky and Telescopeha ^ | 2/29/2012 | Monica Young

[U-238]

Life as we know it exists on a cozy planet in a stable orbit around a sun shining brightly in its sky. But a new study hints that the most common life in the universe might exist deep inside eternal-night worlds far from any star, adrift in the icy dark of interstellar space.

Researchers at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University estimate that "nomad" planets, ejected from their home stellar system and now free-floating through the Milky Way, could outnumber stars by as many as 100,000 to 1. Earlier estimates were more like a handful to 1, though previous studies have only counted unbound planets more massive than Jupiter.

To estimate the number of unbound planets as small as Pluto that could be roaming the galaxy, Louis Strigari (KIPAC), lead author of the study, began with a basic rule of nature: where a few big objects are found, there are many more small, just like a few boulders may be surrounded by thousands of pebbles. Strigari and colleagues calculated the number of unbound planets by extrapolating from the small number detected so far by direct imaging and by gravitational microlensing.

[Caipirabob]

Inability to commit is destroying the galaxy!!!

[tbw2]

I remember reading “When Worlds Collide” and “After Worlds Collide” as a kid. The destruction of earth and jumping to the rogue planet was fascinating but required a serious suspension of belief.
Now we know that rogue planets DO exist!