A bright crater on the dwarf planet Ceres resembling a stop sign on the frozen surface of the airless body is the subject of a stunning new photograph from NASA. The new image was recorded as the Dawn spacecraft was 240 miles away from Ceres.

Haulani Crater is seen in new images from the Dawn spacecraft, marked by eight straight sides, creating an octagon, roughly 21 miles across. This feature is unusual in having straight lines, Typically, natural features on planetary bodies are rounded or curved.

Astronomers recorded a false color image of the crater, in order to examine the distribution of various materials within the feature. Younger material is seen in blue in the new image.

"Haulani perfectly displays the properties we would expect from a fresh impact into the surface of Ceres. The crater floor is largely free of impacts, and it contrasts sharply in color from older parts of the surface," said Martin Hoffmann from the Max Planck Institute for Solar System Research.

The Dawn spacecraft was also utilized to observe several other features on the surface of the airless, rocky body. One of these is the 6-mile-wide Oxo Crater, marked by a region where material has rolled off the edge, onto the ground below. Observations reveal this area has a different composition of minerals than found elsewhere on the dwarf planet.

"Little Oxo may be poised to make a big contribution to understanding the upper crust of Ceres," said Chris Russell from the University of California, Los Angeles.

Investigation of the mysterious bright spots on Ceres is revealing how the distinctive features formed.

The 240-mile altitude over the surface of the frozen dwarf planet is the closest distance from which the Dawn spacecraft has yet conducted observations. This close approach to Ceres has also revealed details on the floor of the Dantu Crater similar to those found on the crater Tycho on Earth's moon.

When Dawn arrived at Ceres, astronomers first spotted the brightly-colored features. Although researchers now believe the bright color is the result of salts, the objects remain an enigma.

Astronomers believe the straight lines seen bordering Haulani could be the result of faults in the surface, combined with pre-existing stress patterns.

Dawn arrived at Ceres on March 6, 2015 and will continue its primary mission exploring the dwarf planet on June 30, 2016.