Dawn Sees Ceres From Lowest Orbit Ever

Landslides and boulders along Occator Crater’s eastern rim are seen from just 30 miles up in this photo taken by NASA’s Dawn spacecraft on June 9. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA’s Dawn spacecraft is now closer to Ceres than ever before. Ceres is the largest known asteroid and the only dwarf planet in the inner solar system. After Dawn entered orbit around Ceres in March 2015, it came no closer than 240 miles (385 km) from its surface. But beginning in April this year, mission control began firing Dawn’s engines to bring it down for a front row view. After a series of complicated maneuvers, the spacecraft now approaches to within 22 miles (35 km) above the surface at closest. Dawn sees Ceres’ heavily cratered dwarf planet from about 127,000 feet up or less than 3½ times the altitude of a jet you’d take to visit Grandma at Christmas.

Dawn’s orbit was changed by degrees from its original loop (outer green) to its current short, closer orbit (inner green ellipse) from mid-April to early June. Its distance from Ceres now ranges from 22 miles at closest to 2,500 miles. NASA / JPL

The spacecraft’s low orbit has already meant some incredibly detailed new views of Ceres’ surface, but it also promises a closer look at how material distributed inside the dwarf planet. Asteroids, moons and planets are lumpy inside with areas of greater and lesser density depending on how they formed and how their interiors evolved over time. Getting “low” allows Dawn to map Ceres’ interior by measuring subtle changes in its gravitational field.

Landslides on Occator’s rim from 27 miles up. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn has already returned several intriguing views of the walls of Occator Crater. Like you, I’m waiting to see new closeups of the briny white spots inside the crater. I’ll post them here as soon as they’re available. Besides photos and gravity measurements, the spacecraft will also explore the minerals that makes up Ceres’ surface in greater detail.

This earlier mosaic of Dawn photos shows Ceres’ Occator crater from 915 miles up. Occator is 60 miles across and 2 miles deep and home to several bright spots, leftover briny coatings after water oozed up from the surface. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The Dawn mission is expected to end when the spacecraft runs out of fuel, which is expected in a matter of a few months. For updates, click here.

A boulder field near Occator Crater’s eastern rim from 30 miles altitude. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Crater upon craters upon crater — rough terrain from 24 miles high. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA