Since the first sighting of the first-discovered and largest asteroid in our solar system was made in 1801 by Giuseppe Piazzi, astronomers and planetary scientists have pondered the make-up of this asteroid/dwarf planet. Its heavily battered and dimpled surface is covered in impact craters. Scientists have long argued that visible craters on the surface meant that Ceres could not be very icy.
Researchers at Purdue University and the NASA’s Jet Propulsion Lab (JPL) now believe Ceres is a very icy object that possibly was once a muddy ocean world. This discovery that Ceres has a dirty ice crust is led by Ian Pamerleau, PhD student, and Mike Sori, assistant professor in Purdue’s Department of Earth, Atmospheric, and Planetary Sciences who published their findings in Nature Astronomy. The duo along with Jennifer Scully, research scientist with JPL, used computer simulations of how craters on Ceres deform over billions of years.
“We think that there’s lots of water-ice near Ceres surface, and that it gets gradually less icy as you go deeper and deeper,” Sori said. “People used to think that if Ceres was very icy, the craters would deform quickly over time, like glaciers flowing on Earth, or like gooey flowing honey. However, we’ve shown through our simulations that ice can be much stronger in conditions on Ceres than previously predicted if you mix in just a little bit of solid rock.”
The team’s discovery is contradictory to the previous belief that Ceres was relatively dry. The common assumption was that Ceres was less than 30% ice, but Sori’s team now believes the surface is more like 90% ice.
“Our interpretation of all this is that Ceres used to be an ‘ocean world’ like Europa (one of Jupiter’s moons), but with a dirty, muddy ocean,'” Sori said. “As that muddy ocean froze over time, it created an icy crust with a little bit of rocky material trapped in it.”
Pamerleau explained how they used computer simulations to model how relaxation occurs for craters on Ceres…
Source www.sciencedaily.com
Ad Amazon : Books UFO
Ad Amazon : Binoculars
Ad Amazon : Telescopes