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Ceres on March 28, 2017

Ceres on March 28, 2017
Ceres on March 28, 2017 Dawn took this photo of Ceres on March 28 from an altitude of 30,100 miles (48,400 kilometers) during its long coast to even greater heights. (The trajectory is described here.) Navigators used this and other pictures taken then to help pin down the spacecraft’s position in orbit in preparation for the third period of ion thrusting on April 4-12. (When we described the plan in February, the thrusting was scheduled for April 3-14. Dawn’s orbital trajectory following the two previous thrust segments was so good that not as much thrusting was needed.) Another navigation image taken after that maneuver is below. When Dawn photographs Occator Crater at opposition on April 29, they will be closer together, so Ceres will show up with 2.4 times more detail than here. More significant will be that the sun will be directly behind Dawn, so Ceres will appear as a fully illuminated disc (like a full moon rather than a half moon, or, to be more appropriate for this mission, like a full dwarf planet). This scene is centered at 33°S, 228°E, and most of what’s illuminated here is east of that location on this map. Near the top is Occator Crater, with its famously bright Cerealia Facula appearing as a bright spot. The crater is 57 miles (92 kilometers) across. Just below and to the right of center is the prominent Urvara Crater. At 106 miles (170 kilometers) in diameter, Urvara is the third largest crater on Ceres. We have seen Urvara in much finer detail several times before, most recently in October. To its right is Yalode, the second largest crater, 162 miles (260 kilometers) in diameter. We saw some intriguing details of its geology last month. The picture below includes the largest crater on Ceres. Full image and caption. NASA / JPL-Caltech / UCLA / MPS / DLR / IDA