NASA announced Wednesday the discovery of 715 new planets strewn among 305 planetary systems, the biggest batch of planets ever unveiled at once, CNN reported.

Observational data from NASA's Kepler space telescope revealed multiple-planet systems much like Earth's solar system.

"We've almost doubled today the number of planets known to humanity," NASA planetary scientist Jack Lissauer told reporters at a teleconference according to The Washington Post.

Nearly 95 percent of the new planets are smaller than Neptune, which is almost four times the size of Earth. The discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets, which are planets outside our solar system.

The Kepler space observatory, which was launched in 2009, was the first NASA mission to find planets similar to Earth that are in, or near, habitable zones - "defined as planets that are the right distance from a star for a moderate temperature that might sustain liquid water," CNN reported.

The planets were verified using data from the first two years of Kepler's voyage.

The research team used a technique called "verification by multiplicity," which relies in part on the logic of probability. Kepler observes 150,000 stars, and has found a few thousand of those to have planet candidates. If the candidates were randomly distributed among Kepler's stars, only a handful would have more than one planet candidate. However, Kepler observed hundreds of stars that have multiple planet candidates. Through a careful study of this sample, these 715 new planets were verified, researchers said in a press release.

"The Kepler team continues to amaze and excite us with their planet hunting results," John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, said in a statement. "That these new planets and solar systems look somewhat like our own, portends a great future when we have the James Webb Space Telescope in space to characterize the new worlds."

Kepler is the first NASA mission to find potentially habitable Earth-size planets. Discoveries include more than 3,600 planet candidates, of which 961 have been verified as bona-fide worlds.

The findings papers will be published March 10 in The Astrophysical Journal.