The fact that the deposits were found
on central peaks is a good indicator that they have an impact origin.
Among these were Copernicus, Gassendi and Tycho, large impact craters
containing central peaks that were thrust upward at the time of impact, bringing material from deep within the lunar crust to the surface.
Scientists and oil prospectors have drilled the crater in the past, but the International Ocean Discovery Program Expedition 364 was the first to explore Chicxulub's
central peak ring.
Central peaks form when material under the impact zone rebounds, forming an upraised rock formation in the middle of the crater.
The most conspicuous feature on Vesta is a giant impact crater located around its south polar region, which is 310 miles (499 kilometers) across and nearly 12 miles (19 km) deep around a «bull's - eye»
central peak rising 11 miles (or 18 km) above the exposed mantle rock of the crater floor — that is characteristic of rock rebounding from an impact.
The technique was able to pinpoint deposits around several
crater central peaks, the craggy mounds that often form in the center of a crater during a large impact.
The impact aftermath killed most life on Earth, but the crater itself (bottom)-- shown with
a central peak — remained hot long after the blast, perhaps creating a hydrothermal system similar to deep - sea vents.
This view shows Alga Crater's
central peak, which is about 3 miles (5 kilometers) wide within the 12 - mile (19 - kilometer) diameter of this southern - hemisphere crater.
Using Moon Mineralogy Mapper data, the researchers looked at the light reflected from each of the four
central peaks.
«Previous studies have suggested that all
the central peaks look very similar, and that was taken as evidence that everything's the same across the basin,» Moriarty said.
«We looked in a little more detail and found significant compositional differences between
these central peaks.
The varying mineralogy in
these central peaks suggests that the SPA subsurface is much more diverse than previously thought.
Specifically, the researchers looked at
the central peaks of four craters within the basin.
Multi-ringed craters are known on the Moon; the inner ring corresponds to
the central peak in smaller craters, while the intermediate 210 - kilometre ring may be the edge of the original hole.
Central peaks are formed when, in the aftermath of an impact, rocks from within the crust rebound upward, bringing layers to the surface that had been buried many kilometers deep.
Some, like tiny Oxo, have terraces, while others, such as the large Urvara Crater (106 miles, 170 kilometers wide), have
central peaks.
«Because
central peaks contain rocks uplifted from depth, some previous studies have assumed the clays found within central peak regions are uplifted too,» said Milliken, assistant professor of Earth, environmental and planetary sciences.
Once positioned, the Curiosity rover began field studies on its drive toward Aeolis Mons (also unofficially known as Mount Sharp),
the central peak within the crater.
Those three mountains are actually
the central peaks of the crater Bhabha, a 64 kilometer (40 mile) wide impact scar on the far side of the Moon.
On a graph this produced a roughly symmetrical bell curve with
a central peak — hence the name.
Remnants of
a central peak, which was up to 0.3 miles (0.5 kilometers) high, can also be seen.
Formed by a deep incision left by the WAIMEA RIVER and extreme rainfall runoff from the island's
central peak, MOUNT WAI`ALE «ALE (one of the wettest places on Earth), WAIMEA CANYON is an awe - inspiring marvel.