Do you ever look up at the starry sky and wonder if we're not alone in the universe? Well, the Sun and its orbiting planets might have that same feeling. Ours is not the only solar system out there!
A solar system is a planetary system made up of planets that orbit or revolve around a single star. Officially, ours is the only one that can truly be called a "solar system" because the word "solar" refers to the sun. But there are countless others. According to NASA, astronomers have discovered more than 2500 stars in our galaxy alone that have planets orbiting them. The search continues...
So what are some of these other planetary systems? TRAPPIST-1 is one of the few that has a specific name. Many of the others, like PSR 1257+12, 47 Ursae Majoris, and 51 Pegasi, are only known by the name given to their star. Astronomers have also named some of the distant planets that are in these systems, like HD 40307g. It has a mass about eight times the size of Earth! Then there's Kepler-16b, which orbits two different stars.
It wasn't until the 1990s that astronomers began to discover other planetary systems. And with new advances in science and technology, who knows what other out-of-this-world wonders we'll find in space? Explore the stars through books and one day you can join the search!