Scientists are calling it a "planet bonanza."
The U.S. space agency, NASA, announced Wednesday the discovery of 715 new planets outside the solar system.
Using the planet-hunting Kepler telescope, the scientists say this doubles the number of known planets to about 1,700.
They say all the new planets are in systems just like our solar system, where they orbit around one large star.
The scientists say at least four of the newly found planets may be within what they call the habitable zone of their stars, meaning it is not too hot or too cold for water.
But the scientists say they know little about the new planets and cannot say whether they can support life.