Every Star Has A Planet

Romantic, isn't it?

A new study suggests that every star in our galaxy has at least one planet. This means that in the Milky Way alone, there's at least 100 billion planets, and likely closer to 160 billion. So far, about 700 exoplanets, or planets outside of our solar system, have been confirmed to exist, but these findings send that figure, well, to the stars. Astrophysicists from the U.K. and France used a new technique, known as microlensing, to determine that number. So, what is this microlensing? Via Space's Mike Wall:

In gravitational microlensing, scientists watch what happens when a massive object passes in front of a star from our perspective on Earth. The nearby object's gravitational field bends and magnifies the light from the distant star, acting like a lens.

This produces a light curve — a brightening and fading of the faraway star's light over time — whose characteristics tell astronomers a lot about the foreground object.

In many cases, this nearby body is a star. If it has any planets, even ones in relatively far-flung orbits, these can generate secondary light curves, alerting researchers to their presence.

The research team found three instances of secondary light curves – a phenomenon that's exceptionally rare. From that data, as well as earlier research that found seven exoplanets via the same method, they extrapolated that every star would have on average 1.6 planets. About one in six stars should have a planet the size of Jupiter, one in two should have a planet the size of Neptune, and about two-thirds of all stars in the Milky Way should have "super-Earths" orbiting them. And with that many billions of planets out there, the chances of our precious little Earth being the lone life-supporting planet in the galaxy have become that much slimmer.