Tag: asteroids

The Dawn science team today released a set of close-up images of several craters on Ceres, showing a number of geological features similar but different than features seen in lunar craters.

The image on the right, of Kupalo Crater, shows the same kind of bright material on the rim that is seen on the floor of Occator Crater as two bright areas. The bright material is now believed to be a salt deposit leeched from beneath the surface. Other craters showed extensive fractures in their floor as well as lobes and scarps.

The Dawn science team has now released new high resolution images of Ceres taken from the spacecraft’s lowest orbit.

Dawn took these images of the southern hemisphere of Ceres on Dec. 10, at an approximate altitude of 240 miles (385 kilometers), which is its lowest-ever orbital altitude. Dawn will remain at this altitude for the rest of its mission, and indefinitely afterward. The resolution of the new images is about 120 feet (35 meters) per pixel.

Among the striking views is a chain of craters called Gerber Catena, located just west of the large crater Urvara. Troughs are common on larger planetary bodies, caused by contraction, impact stresses and the loading of the crust by large mountains — Olympus Mons on Mars is one example. The fracturing found all across Ceres’ surface indicates that similar processes may have occurred there, despite its smaller size (the average diameter of Ceres is 584 miles, or 940 kilometers). Many of the troughs and grooves on Ceres were likely formed as a result of impacts, but some appear to be tectonic, reflecting internal stresses that broke the crust.

Make sure to click on the link. The images show that Ceres is not the dull boring surface that the wider shots have suggested.

Using data during Dawn’s first orbit of Ceres German scientists have compiled a global atlas of the dwarf planet.

The images used for this are the wide angle survey images, which won’t show the smallest objects because they were taken from about 2,700 miles above the surface. Nonetheless, this atlas gives scientists a baseline for studying the giant asteroid.

The Dawn science team have released their first images of the north and south poles of Ceres.

The region around the south pole appears black in this view because this area has been in shade ever since Dawn’s arrival on March 6, 2015, and is therefore not visible. At the north polar region, craters Jarovit, Ghanan and Asari are visible, as well as the mountain Ysolo Mons. Near the south pole, craters Attis and Zadeni can be seen.

Engineers have fired up Dawn’s ion engine and have begun lowering the spacecraft’s orbit downward.

The spacecraft is now on its way to the final orbit of the mission, called the low-altitude mapping orbit. Dawn will spend more than seven weeks descending to this vantage point, which will be less than 235 miles (380 kilometers) from the surface of Ceres. In mid-December, Dawn will begin taking observations from this orbit, including images at a resolution of 120 feet (35 meters) per pixel.

They’ve also released a nice mosaic showing the double bright spots in Occator Crater as well as the surrounding terrain.