NASA says they've discovered seven Earth-like planets orbiting a star that may have the potential to sustain life. They're orbiting a star called TRAPPIST-1 about 40 light years away. Astronomers say the planets are rocky, like Earth. Some of them may even have oceans. The NASA scientists say this is a major discovery, they've never seen anything like it before. Researchers expect to learn more about these planets within a few years.