LOS ANGELES -- It's icy, rocky and bigger than Pluto. And according to scientists who found it orbiting the sun, it's the newest planet on our solar system's block. The planet (the farthest-known object in the solar system)  is currently 9 billion miles away from the sun, or about three times Pluto's current distance from the sun.

"This is the first object to be confirmed to be larger than Pluto in the outer solar system," Michael Brown, a planetary scientist at the California Institute of Technology.

This artist's concept, released by NASA, shows the planet catalogued as 2003UB313 at the lonely outer fringes of our solar system. Our Sun can be seen in the distance. The new planet, which is yet to be formally named, is at least as big as Pluto and about three times farther away from the Sun than Pluto. It is very cold and dark.

Astronomers do not know the new planet's exact size, but its brightness shows that it is at least as large as Pluto and could be up to 1 1/2 times bigger. The research was funded by NASA.

It has taken scientists this long to find the planet because its orbit is at an angle compared to the orbits of most planets. The new planet is rocky and icy, similar to Pluto, Brown said. It is possible that they want to call the new planet Xena!

Scientists are now arguing about whether or not Pluto and this new discovery should actually be called planets. Pluto was originally thought to be the size of Earth, but we now know that it is actually only about a fifth of the size of our moon. This new planet is also very much smaller than the 8 main planets in our solar system. So how many planets do we have in our solar system? 8 or 9 or 10?