100 Billion Earth-like Planets Could be Located with New Technique: Our World Gets Some Company

Watch out, Earth. You have competition. Astronomers estimate that there could be as many as 100 billion Earth-like planets out in space--and now they have a way to find them. Researchers at the University of Auckland have proposed a new method for finding these planets.

The technique, which is described in the journal Monthly Notices of the Royal Astronomical Society, uses gravitational microlensing in order to locate the planets. Microlensing measures the deflection of light from a distant star that passes through a planetary system en route to Earth--an effect that was first predicted by Einstein in 1936. This technique can potentially allow scientists to detect planets that are around the size of Earth. In addition to the microlensing, the scientists also use data from the NASA Kepler space telescope.

"Our proposal is to measure the number of Earth-mass planets orbiting stars at distances typically twice the Sun-Earth distance," said Phil Yock, lead author, in a press release. "Our planets will therefore be cooler than the Earth. By interpolating between the Kepler and the MOA results, we should get a good estimate of the number of Earth-like, habitable planets in the Galaxy. We anticipate a number in the order of 100 billion."

In recent years, microlensing has been used to detect several larger planets around the sizes of Neptune and Jupiter. Yet detecting the comparatively tiny Earth-sized planets would be far harder. In order to accomplish this goal, the researchers have proposed a worldwide network of moderate-sized robotic telescopes that could potentially monitor them.

In fact, a network of this kind is currently being deployed by Las Cumbres Observatory Global Telescope Network (LCOGT) in collaboration with SUPA/St. Andrews. It includes three telescopes in Chile, three in South Africa, three in Australia and one each in Hawaii and Texas. This network will be used to study microlensing events, which could mean that a lot more Earth-like planets could be found sometime soon.

So will we find life on other planets? That's another question entirely. That said, Earth could be getting some company in future years.