Researchers Say there might be 100 Billion Earth-Like Planets in the Universe

There might be about 100 billion Earth-like planets in our galaxy, according to researchers from The University of Auckland. The study team has proposed a new method of finding planets that are like Earth.

The study uses a strategy called as gravitational microlensing, which is now used by researchers from Japan and New Zealand. Gravitational microlensing is when a star appears brighter, when a smaller object passes between the star and the observer. Since 2004, many extasolar planets have been discovered using this technique.

Dr. Phil Yock from the University of Auckland's Department of Physics and lead author of the study said that the study will require data from both microlensing and the NASA Kepler space telescope.

"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. 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," Yock said in a news release.

The study will be looking at planets that are roughly similar to Earth in mass but are at twice the distance between Earth and Sun, meaning these planets will be colder than our planet.

"By interpolating between the Kepler and MOA (Microlensing Observations in Astrophysics) 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," Yock said.

Tiny objects like planets aren't easy to detect, as they are hidden in the glare of bright objects like the sun.

Simulations developed by a study team led by Yock found that Earth-sized planets can be detected around the stars if they are hunted using a network of moderate-sized telescopes. Microlensing checks for a planet's presence by using the deflection of light caused by the planet, while Kepler measures the loss of light in the star when an object (like a planet) moves between the star and the observer.

The proposal is published in the journal Monthly Notices of the Royal Astronomical Society.