A century ago, people thought of the solar system as the sun, eight planets, and thousands of asteroids. Today we know there's much more. We think of particles we can't even see as important parts of the solar system. So where does true interstellar space begin? Continue reading →
¡SkyCaramba! Weekly astronomy blog for the week ending June 14, 2014
About a century ago, people generally thought the solar system had the sun in the center, eights planets and hundreds of asteroids orbiting it, and a few comets here and there. When someone discovered the object eventually named Pluto, people thought of the solar system as having gotten a little bigger. In the decades since, we have come to accept that the solar system reaches out even farther and is more than just planets.
In addition to asteroids orbiting between Mars and Jupiter, there are numerous objects orbiting beyond Pluto. Many of them are icy objects in a region called the Kuiper Belt. Farther out is another zone of icy objects called the Oort Cloud. An object there named Sedna is about three times as far from the sun as Neptune.
The Kuiper Belt and Oort Cloud are thought to ...