University of Auckland researchers have proposed a new method for finding Earth-like planets in our galaxy and they anticipate that the number will be on the order of 100 billion.
Milky Way Galaxy (credit: NASA/JPL-Caltech)
The research supports an earlier estimate based on extrapolations of Kepler data.
The new research uses a technique called gravitational microlensing, currently used by a Japan-New Zealand collaboration called MOA (Microlensing Observations in Astrophysics) at New Zealand’s Mt. John Observatory.
“Kepler finds Earth-sized planets that are quite close to parent stars, and it estimates that there are 17 billion such planets in the Milky Way,” says Dr. Phil Yock from the University of Auckland’s Department of Physics. These planets are generally hotter than Earth, although some could be of a similar temperature (and therefore habitable) if they’re orbiting a cool star called a red dwarf.”
Kepler measures the loss of light from a star when a planet orbits between us and the star; microlensing measures the deflection of light from a distant star that passes through a planetary system en route to Earth — an effect predicted by Einstein in 1936.