It is one of the many mysteries of Ceres – a gigantic pyramid in among the vast craters and ‘alien spots’.

Now, Nasa has revealed stunning new close up images of the three mile high mountain Ahuna Mons.

They reveal the ‘pyramid’ is in fact a dome with smooth, steep walls – one of which appears to glow.

The mysterious mountain Ahuna Mons is seen in this mosaic of images from NASA’s Dawn spacecraft. Dawn took these images from its low-altitude mapping orbit, from an altitude of 240 miles (385 kilometers) in December 2015.

One year ago, on March 6, 2015, Nasa’s Dawn spacecraft slid gently into orbit around Ceres, the largest body in the asteroid belt between Mars and Jupiter.

Since then, the spacecraft has delivered a wealth of images and other data that open an exciting new window to the previously unexplored dwarf planet.

‘Ceres has defied our expectations and surprised us in many ways, thanks to a year’s worth of data from Dawn. We are hard at work on the mysteries the spacecraft has presented to us,’ said Carol Raymond, deputy principal investigator for the mission, based at Nasa’s Jet Propulsion Laboratory, Pasadena, California.

Among Ceres’ most enigmatic features is a tall mountain the Dawn team named Ahuna Mons.

This mountain appeared as a small, bright-sided bump on the surface as early as February 2015 from a distance of 29,000 miles (46,000 kilometers), before Dawn was captured into orbit.

As Dawn circled Ceres at increasingly lower altitudes, the shape of this mysterious feature began to come into focus.

From afar, Ahuna Mons looked to be pyramid-shaped, but upon closer inspection, it is best described as a dome with smooth, steep walls.

Dawn’s latest images of Ahuna Mons, taken 120 times closer than in February 2015, reveal that this mountain has a lot of bright material on some of its slopes, and less on others.

On its steepest side, it is about 3 miles (5 kilometers) high.

Scientists are beginning to identify other features on Ceres that could be similar in nature to Ahuna Mons, but none is as tall and well-defined as this mountain.

‘No one expected a mountain on Ceres, especially one like Ahuna Mons,’ said Chris Russell, Dawn’s principal investigator at the University of California, Los Angeles.

‘We still do not have a satisfactory model to explain how it formed.’

About 420 miles (670 kilometers) northwest of Ahuna Mons lies the now-famous Occator Crater.

Before Dawn arrived at Ceres, images of the dwarf planet from NASA’s Hubble Space Telescope showed a prominent bright patch on the surface.

As Dawn approached Ceres, it became clear that there were at least two spots with high reflectivity.

This side-perspective view of Ceres’ mysterious mountain Ahuna Mons was made with images from NASA’s Dawn spacecraft to create a 3-D (anaglyph) view.

As the resolution of images improved, Dawn revealed to its earthly followers that there are at least 10 bright spots in this crater alone, with the brightest area on the entire body located in the center of the crater. It is not yet clear whether this bright material is the same as the material found on Ahuna Mons.

‘Dawn began mapping Ceres at its lowest altitude in December, but it wasn’t until very recently that its orbital path allowed it to view Occator’s brightest area.

‘This dwarf planet is very large and it takes a great many orbital revolutions before all of it comes into view of Dawn’s camera and other sensors,’ said Marc Rayman, Dawn’s chief engineer and mission director at JPL

Previous video also shows a prominent mountain with bright streaks on its steep slopes. The peak’s shape has been likened to a cone or a pyramid, and it appears to be about four miles (6 kilometers) high. This means the mountain has about the same elevation as Mount McKinley in Denali National Park, Alaska, the highest point in North America.It has amazed, baffled and stunned scientists.

Now, Nasa’s Dawn spacecraft has been used to create a stunning flyover of dwarf planet Ceres.

The crater has bright material exposed on its rim, which could be salts, and its flat floor likely formed from impact melt and debris.

Researchers will be looking closely at whether this material is related to the ‘bright alien spots’ of Occator Crater.

Kupalo, which measures 16 miles (26 km) across and is located at southern mid-latitudes, is named for the Slavic god of vegetation and harvest.

‘This crater and its recently-formed deposits will be a prime target of study for the team as Dawn continues to explore Ceres in its final mapping phase,’ said Paul Schenk, a Dawn science team member at the Lunar and Planetary Institute, Houston.

Dawn’s low vantage point also captured the dense network of fractures on the floor of 78-mile-wide (126 km -wide) Dantu Crater.

One of the youngest large craters on Earth’s moon, called Tycho, has similar fractures.

This cracking may have resulted from the cooling of impact melt, or when the crater floor was uplifted after the crater formed.

A 20-mile (32 km) crater west of Dantu is covered in steep slopes, called scarps, and ridges.

The features likely formed when the crater partly collapsed during the formation process.

The curvilinear nature of the scarps resembles those on the floor of Rheasilvia, the giant impact crater on protoplanet Vesta, which Dawn orbited from 2011 to 2012.

Dawn’s other instruments also began studying Ceres intensively in mid-December.

The visible and infrared mapping spectrometer is examining how various wavelengths of light are reflected by Ceres, which will help identify minerals present on its surface.

Dawn’s gamma ray and neutron detector (GRaND) is also keeping scientists busy.

Data from GRaND help researchers understand the abundances of elements in Ceres’ surface, along with details of the dwarf planet’s composition that hold important clues about how it evolved.

The spacecraft will remain at its current altitude for the rest of its mission, and indefinitely afterward. The end of the prime mission will be June 30, 2016.

‘When we set sail for Ceres upon completing our Vesta exploration, we expected to be surprised by what we found on our next stop. Ceres did not disappoint,’ said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

‘Everywhere we look in these new low- altitude observations, we see amazing landforms that speak to the unique character of this most amazing world.’

Dawn is the first mission to visit a dwarf planet, and the first mission outside the Earth-moon system to orbit two distinct solar system targets.

After orbiting Vesta for 14 months in 2011 and 2012, it arrived at Ceres on March 6, 2015.

It recently sent back a series of stunning images of dramatic craters, strange ‘alien’ spots and pyramid mountains.

Now, the Dawn spacecraft has revealed its surface in unprecedented detail with the latest images sent back from the dwarf planet.

Dawn took the images near its lowest ever altitude to Ceres, at 240 miles (385 km) from the surface, between December 19 and 23.

Kupalo Crater, one of the youngest craters on Ceres, shows off fascinating features at the high image resolution of 120 feet (35 meters) per pixel. 

This image from the Dawn spacecraft shows part of Messor Crater (25 miles or 40 km, wide), located at northern mid-latitudes on Ceres. The scene shows an older crater in which a large lobe-shaped flow partly covers the northern (top) part of the crater floor. The flow is a mass of material ejected when a younger crater formed just north of the rim. The image resolution is 120 feet (35 meters) per pixel

Source: (Mail Online)