A NASA spacecraft orbiting the asteroid Vesta is revealing new details about the huge space rock's surface, including a massive mountain that rises taller than Mt. Everest on Earth.

NASA's Dawn probe has been circling Vesta since mid-July, when it arrived in the asteroid belt that orbits the sun between Mars and Jupiter. So far, Dawn has beamed back surprising views of Vesta that revealed an enormous mountain in the asteroid's southern hemisphere and show that its crater surface is incredibly diverse place.

"We are learning many amazing things about Vesta, which we call the smallest terrestrial planet," Chris Russell, principal investigator of the Dawn mission, said in a statement. "Like Earth, Mars, Venus and Mercury, Vesta has ancient basaltic lava flows on the surface and a large iron core … The south polar mountain is larger than the big island of Hawaii, the largest mountain on Earth, as measured from the ocean floor. It is almost as high as the highest mountain in the solar system, the shield volcano Olympus Mons on Mars." [SPACE]

Vesta's giant southern mountain is nearly as tall as Olympus Mons, the largest mountain (and volcano) in the solar system, which soars about 15 miles (24 kilometers) above the surface. On Earth, the largest terrestrial volcano is Mauna Loa in Hawaii, which rises up 6 miles (9 km) high, including the portion of the volcano that extends underwater to the sea floor. Mount Everest, the tallest mountain above sea level on Earth, is a paltry 5.5 miles (8.85 km) tall. [Latest Photos of Asteroid Vesta]

Dawn also revealed that Vesta's surface appears to be much rougher than most asteroids in the main asteroid belt, which is a vast region full of space rocks between the orbits of Mars and Jupiter.

Additionally, preliminary estimates of crater age dates on Vesta suggest that regions in the southern hemisphere are far younger than in the north — with some areas in the southern hemisphere only about 1 to 2 billion years old.

The findings were presented today at the 2011 European Planetary Science Congress and the Division for Planetary Sciences Joint Meeting in Nantes, France.