Why Pluto looks young

 

Image courtesy of NASA/JHUAPL/SwRI

 

Joel Kontinen

 

When NASA’s New Horizons spacecraft flew past Pluto in July 2015, scientists were expecting to see a dwarf planet that looked old and its largest moon Charon to be full of impact craters.

However, what they saw blew their socks off, as NASA researcher Cathy Olkin put it in a New Horizons press conference.

Pluto looked far too young to fit into a 4.6 billion year old universe, and so did Charon.
Subsequent images sent by New Horizons showed more evidence for youth.

Scientist have proposed two interpretations of a cold Pluto.  ”The first which involves Pluto forming over millions of years by the slow accretion of cold objects. This version of Pluto eventually would have coalesced enough material that radiative heating from the inside would melt the subsurface ocean. The other hypothesis involves a “warm” or “hot” Pluto, in which Pluto formed over a shorter time period in violent collisions that heated its interior, formed the ocean, and eventually cooled the planet into the majority ice ball we know today. "

Anyhow, Pluto is just cold but its geography tells it is young. 

Source:

Wendel, JoAnna, 2022, Clues to Pluto’s History Lie in Its Faults Phys. org. 1 February.