Ice in Ceres' Shadowed Craters Linked to Tilt History
https://www.nasa.gov/feature/jpl/ice-in-ceres-shadowed-craters-linked-to-tilt-history
Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity
from these gas giants has an appreciable effect on Ceres' orientation. In a new study, researchers from NASA's Dawn mission calculate that
the axial tilt of Ceres -- the angle at which it spins as it journeys around the sun -- varies widely over the course of about 24,500 years.
Astronomers consider this to be a surprisingly short period of time for such dramatic deviations.
Changes in axial tilt, or "obliquity," over the history of Ceres are related to the larger question of where frozen water can be found on Ceres'
surface, scientists report in the journal Geophysical Research Letters. Given conditions on Ceres, ice would only be able to survive at extremely
cold temperatures -- for example, in areas that never see the sun.
"We found a correlation between craters that stay in shadow at maximum obliquity, and bright deposits that are likely water ice," said Anton Ermakov,
postdoctoral researcher at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of the study. "Regions that never see sunlight
over millions of years are more likely to have these deposits."
