NASA announced Wednesday, discovery of 715 planets outside our solar system. Four of the newly-discovered planets are in the "habitable zone," meaning that they have the potential to support life.

By far, this was the largest number of planets found at one time. Before Wednesday, the total number of exoplanets found was about 1,000, CNN reported.

The planets discovered by Kepler space telescope orbit around 305 stars, meaning that they belong to multi-planet systems like the solar system.

NASA astronomers used a new technique called verification by multiplicity to search and study the planets. Data for the study came from observations made by Kepler between May 2009 and March 2011.

Verification by multiplicity relies on probability. Researchers used the technique to sort out the stars that are more likely to  have planets around them, according to CNN.

"Four years ago, Kepler began a string of announcements of first hundreds, then thousands, of planet candidates --but they were only candidate worlds. We've now developed a process to verify multiple planet candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds," Jack Lissauer, planetary scientist at NASA's Ames Research Center in Moffett Field, Calif., co-author of the research.

Kepler was launched in 2009 to search for earth-like planets outside the solar system. The discovery of planets within the habitable zone shows that there might be other planets in the galaxy that can support life.

"The Kepler team continues to amaze and excite us with their planet hunting results," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, according to a news release. "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."

The latest study results will be published in The Astrophysical Journal.

In a tweet announcing the news, NASA wrote: 

Today we collectively tick forward the known exoplanet count to around 1,700. A remarkable milestone! https://t.co/TQrqnOWI3z #Kepler715

- NASA Kepler (@NASAKepler) February 26, 2014.