During its orbit, NASA's Dawn spacecraft spotted what is likely to be an inactive volcano on the surface of dwarf planet Ceres. This planet is also the largest object found between Jupiter and Mars. What is it about the volcano on the dwarf planet that makes the discovery surprising?

"It's totally cool and unexpected," exclaimed Christopher Russell, the chief scientist at the University of California.

The volcano spotted on planet Ceres is said to be as tall as Mount Everest. On Thursday, scientists also add that it had erupted approximately a hundred million years ago. This is not the first time that evidence of volcanic activity has been spotted on a wealth of other planets.

Images captured by the Dawn spacecraft of planet Ceres was analyzed by Ottaviano Ruesch of NASA Goddard Space Flight Center. According to Ruesch and his team, the dome-shaped mountain spotted on Ceres is made of mud and salt, which is completely different from volcanoes found in the outer solar system that are made out of ice.

Dawn spacecraft orbited Ceres for months but no volcanic eruptions were noted. As for their discovery of the inactive volcano, it was published in the journal of Science. Other notable studies published include minerals and ice, as well as impact craters on the surface of Ceres.

Ceres was once considered a planet but has been downgraded to an asteroid. In 2006, it has then been classified as a dwarf planet, which is the same as the former ninth planet, Pluto. As for the Dawn spacecraft, Ceres is its second and last stop.

NASA's Dawn spacecraft had wrapped up its mission to Ceres back in June. It flew approximately 240 miles above Ceres. While NASA had originally planned for a mission extension, engineers decided to cut the mission short to save on fuel. Dawn will be moving away from Ceres, at 910 miles above, for a new round of observations.