Pluto’s craters give insights into solar system’s building blocks

NASA scientists have presented more details of Pluto’s long history of geologic activity at the 47th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences in National Harbor, Maryland.

Pluto’s surface varies in age, they say, from ancient, to intermediate, to relatively young, according to a count crater impacts on the dwarf planet. 

The more crater impacts, the older the region likely is. Crater counts of surface areas on Pluto indicate that it has surface regions dating to just after the formation of the planets of our solar system, about four billion years ago.

But there also is a vast area that was, in geological terms, born yesterday – meaning it may have formed within the past 10 million years. This area, informally named Sputnik Planum, appears on the left side of Pluto’s “heart” and is completely crater-free in all images received, so far.

“We’ve mapped more than a thousand craters on Pluto, which vary greatly in size and appearance,” said postdoctoral researcher Kelsi Singer, of the Southwest Research Institute (SwRI) in Boulder, Colorado. 

“Among other things, I expect cratering studies like these to give us important new insights into how this part of the solar system formed.”

The crater counts are also giving insights into the structure of the Kuiper Belt itself. The lack of smaller craters across Pluto and its large moon Charon indicate the Kuiper Belt, which is an unexplored outer region of our solar system, likely had fewer smaller objects than some models had predicted.