Nasa's Dawn Probe Takes More Photos of Mysterious Bright Spots on Ceres

New images of Ceres from Nasa's Dawn spacecraft has provided more visible images of mysterious bright spots and also revealed a pyramid-shaped peak towering over a relatively flat landscape.

Dawn has been studying the dwarf planet Ceres, the largest object in the main asteroid belt between Mars and Jupiter, in detail from its second mapping orbit, which is 4,400 km above Ceres.

A new view of its intriguing bright spots, located in a crater 90km across, shows even more small spots in the crater than were previously visible, the US space agency said.

At least eight spots can be seen next to the largest bright area, which scientists think is approximately nine kilometres wide.

Although ice and salt are leading candidates that could explain these spots, scientists are considering other options, too.

"The surface of Ceres has revealed many interesting and unique features. For example, icy moons in the outer solar system have craters with central pits but on Ceres central pits in large craters are much more common," said Carol Raymond, deputy principal examiner for the Dawn mission, based at Nasa's Jet Propulsion Laboratory in Pasadena, California.

"These and other features will allow us to understand the inner structure of Ceres that we cannot sense directly."

Dawn's visible and infrared mapping spectrometer allows scientists to identify specific minerals present on Ceres by looking at how light is reflected.

Each mineral reflects the range of visible and infrared-light wavelengths in a unique way and this signature helps scientists determine the components of Ceres.

So, as the spacecraft continues to send back more images and data, scientists will learn more about the mystery bright spots, Nasa said.

In addition to the bright spots, the latest images also show a mountain with steep slopes protruding from a relatively smooth area of the dwarf planet's surface.

The structure rises about five kilometres above the surface.

Dawn is the first mission to visit a dwarf planet and the first to orbit two distinct targets in our solar system.

It arrived at Ceres on March 6, 2015 and will remain in its current altitude until June 30.