Last month, Pluto was tossed out of the family of planets by the International Astronomical Union - but perhaps its not all bad, because even as Pluto has lost one family, it seems to have gained another.

Today, the "hot new thing" in planetary science is the Kuiper Belt - a ring of icy debris that orbits outside the Solar System proper. Many of these "Kuiper objects" - of which Pluto is now considered a part - is the "attic of the solar system," a veritable archaeological treasure house of artifacts dating from its earliest days.

Astronomers have identified some 1,100 Kuiper Belt objects , and there may be has many as half a million more. Many of these bodies are larger than 20 miles wide. One appears to be mostly rock with a coating of ice. Some are big snowballs. Some are less dense than ice, indicating a Swiss-cheese-like structure. A lot of them have moons. "The more we learn, the weirder it looks," says Harold Levinson of the Southwest Research Institute in Boulder, Colorado.

Many Kuiper Belt objects have orbits similar to Pluto’s, and have been dubbed the "Plutinos."

Like Pluto, these have orbits, often at a sharp angle to the rest of the solar system. At least one of these -  nicknamed "Xena" -  is larger than Pluto.