Peter Zois, age 10, of Somerville, Mass,,

How many Solar Systems are there?

A few years ago, we had no proof that there were any other solar systems in the world, besides our own. Since then, a few planets have been spotted in photographs taken by our far‑seeing telescopes, And a planet, of course, means that a star has a solar system. The newly discovered planets are whoppers, much, much bigger than our giant Jupiter ‑ which means that there are most likely countless planets too small for our telescopes to spot.

We can count Just a few other solar systems for certain, but the astronomers estimate that there are many millions of them. Old Sol is not the only parent star with a family of planets, Some experts think that more than half of the 100 billions of stars in our Galaxy have planets ‑ and there are billions of other galaxies in the universe.