NASA’s Dawn spacecraft reached its lowest-planned orbit around the asteroid Ceres 6 June, giving researchers a bird’s eye view of the cratered surface, including enigmatic Occator Crater with its famously bright deposits of sodium carbonate. Passing within a scant 35 kilometres (22 miles) of the surface, Dawn’s latest images zoom in on Cerealia Facula, a large deposit of sodium carbonate near the center of the crater. Project manager Marc Rayman of NASA’s Jet Propulsion Laboratory says “acquiring these spectacular pictures has been one of the greatest challenges in Dawn’s extraordinary extraterrestrial expedition, and the results are better than we had ever hoped.”
Data from Dawn in the coming weeks may help resolve questions about the origin of the sodium carbonate deposits, whether they originated in a shallow, sub-surface reservoir or from a deeper source of salty water making its way to the surface through fractures.
This Dawn image shows a wide-angle view of Occator Crater:
Here is a more zoomed-in view, highlighting the central deposits of sodium carbonate. Note the mesa like mound to the left of center:
Here is the latest image from the Dawn spacecraft, a composite captured on 22 June, showing the unusual mound in striking relief:
“The first views of Ceres obtained by Dawn beckoned us with a single, blinding bright spot,” said Carol Raymond, Dawn principal investigator at JPL. “Unraveling the nature and history of this fascinating dwarf planet during the course of Dawn’s extended stay at Ceres has been thrilling, and it is especially fitting that Dawn’s last act will provide rich new data sets to test those theories.”