A salty rock story
Micrometeorites continually falling on the surface of Ceres should darken salt deposits, suggesting these white regions are geologically young. This finding drove engineers to utilize Dawn to uncover the mysteries of the bright patches.
Analysis revealed these patches are less than two million years old. Chemistry in the region was found to include salt molecules bounding to water and ammonium chloride, a salt.
Dawn found evidence of liquid water reaching the surface in these regions, adding to the evidence for liquid oceans beneath the surface of Ceres.
“The scientists found two main pathways that allow liquids to reach the surface. For the large deposit at Cerealia Facula, the bulk of the salts were supplied from a slushy area just beneath the surface that was melted by the heat of the impact that formed the crater about 20 million years ago. The impact heat subsided after a few million years; however, the impact also created large fractures that could reach the deep, long-lived reservoir, allowing the brine to continue percolating to the surface,” Dawn Principal Investigator Carol Raymond stated.
Powered by ion engines, Dawn was the first spacecraft to orbit two main targets — the giant asteroid Vesta and Ceres. When the robotic explorer ran low on hydrazine fuel needed to maintain orientation and generate power, engineers sent the vehicle into a high orbit, preventing the vehicle from impacting on Ceres for several decades.
If water can remain as a liquid on Ceres, it may be possible for water to remain liquid on other dwarf planets, researchers suggest. With the discovery of lifeforms pushing the limits of life on Earth, chances become ever greater that we will soon find evidence for life on other worlds.
This article was originally published on The Cosmic Companion by James Maynard, founder and publisher of The Cosmic Companion. He is a New England native turned desert rat in Tucson, where he lives with his lovely wife, Nicole, and Max the Cat. You can read this original piece here.
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