Possibly the most striking is an image showing Kupalo Crater (above), one of Ceres’ many curious aspects. Kupalo Crater, 16 miles (26 kilometers) across, is one of the youngest craters on Ceres. The rim and walls of the crater are unusually bright. NASA scientists speculate that these features highly reflective qualities could be caused by salts while Kupalo Crater’s flat floor most probably formed from impact melt and debris.
Features on dwarf planet Ceres that piqued the interest of scientists throughout 2015 stand out in exquisite detail in the latest images from NASA’s Dawn spacecraft which recently reached its lowest-ever altitude above Ceres.
The Dawn spacecraft, launched during September 2007, entered orbit around Ceres, now classed as a dwarf planet and located in the Asteroid Belt between Mars and Jupiter, in March 2015. Prior to arrival at Ceres, Dawn first executed a fly-by of Mars before paying a visit to Vesta, the second most massive object in the Asteroid Belt.
Dawn captured the latest images, from an altitude of just 240 miles (385 kilometers) between December 19 and 23, 2015.
One aspect to be addressed by researchers is whether Kupalo Crater’s reflective qualities are in any way related to perhaps the most puzzling feature so far discovered on Ceres, namely the “bright spots” of Occator Crater.
Occator Crater, from images previously returned by Dawn, at first glance appeared to show a light beaming out from Ceres’ surface. Digital Journal previously highlighted the brightest of these, dubbed “Spot 5”.
Dawn zoomed in on a dense network of fractures, the most notable feature of the 78-mile-wide (126-kilometer-wide) Dantu Crater.
NASA draws the comparison between Dantu’s floor fractures and a similar pattern observed at Tycho, one of the youngest large craters discovered on our very own Moon. The fracturing could have been caused when impact melt cooled or when the crater floor heaved upwards after the crater formed.
Dawn also returned images of a 20-mile (32-kilometer) crater west of Dantu showing an impact zone punctuated by steep slopes, called scarps, and ridges. According to NASA, such features likely formed when the crater partly collapsed during the formation process.
The 20-mile-wide (32-kilometer-wide) crater is located just west of the larger, named crater Dantu at northern mid-latitudes on Ceres.
Dawn will now remain at its present altitude until its projected mission end-date of June 30, 2016. If Dawn continues to perform well there’s every likelihood NASA will extend the mission with Dawn continuing to transmit images of enigmatic Ceres indefinitely.
Dawn’s circuitous mission to the dwarf planet has paid dividends for space scientists while possibly raising more questions than it’s answered. In this respect, data from Dawn’s gamma ray and neutron detector (GRaND) should help researchers gauge the elements present on Ceres’ surface. That, along with details of the dwarf planet’s composition, should give pointers as to how this puzzling dwarf planet evolved.
University of California’s Chris Russell, the mission’s principal investigator, summed up the voyages of Dawn: “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,” adding, “Everywhere we look in these new low- altitude observations, we see amazing landforms that speak to the unique character of this most amazing world.”
