The biggest discovery in new images of Pluto is what scientists didn't see

NASA’s New Horizons team has just revealed the most detailed images of Pluto yet, and the space agency is ecstatic about what it has seen: a smooth, young, and active surface on what had been thought to be an old, battered ball of ice.

The New Horizons spacecraft took the following images on July 14, almost a decade after the mission launched, shortly before the spacecraft’s closest approach to Pluto at a distance of 478,000 miles away.

The latest close-up image reveals a young, pointy mountain range that is about 11,000 feet high. Members of the New Horizons team believe this region, which covers less than 1% of Pluto’s surface, is no more than 100 million years old — a youngster in the 4.56-billion-year-old solar system.

What’s more: The mountain ranges are probably still growing.

“This is one of the youngest surfaces we’ve ever seen in the solar system,” Jeff Moore, a member of the New Horizons geology, geophysics, and imaging team, said in a NASA press release.

Scientists expected Pluto’s surface to be heavily marked with craters from billions of years of pummelling by space rocks. Instead the team discovered the dwarf planet’s surface — or at least the part seen so far — to be relatively free of craters.

“We have not yet found a single impact crater on this image,” John Spencer, one of the co-investigators on the New Horizons team, said in a news conference. “This means that Pluto has a very young surface.”

But that doesn’t mean it’s smooth. The mountain range is about as tall as Earth’s Rocky Mountains.

Those are signs the dwarf planet is geologically active. Moore, Spencer, and the researchers can’t explain where that activity is coming from, because Pluto doesn’t have the push and pull of gravity from a larger planet to heat it and keep it active.

This tells us some other type of process must be making Pluto’s surface geologically active.

One theory is that radiation in the planet keeps it warm and active.

“We know there’s radioactive material in Pluto and Charon,” Spencer said, referring to Pluto’s largest moon, “as the same as bodies in our solar system. This may be telling us that even in small bodies, if they’re icy, radioactive heat is enough to produce [geologic] activity.”

Another possibility is a thawing and freezing ocean just under Pluto’s surface, the researchers said during a NASA news conference.

The team has plenty of work ahead as data and images continue to stream in over the following days, weeks, and months.

Pluto will “send a lot of geophysicists back to the drawing boards,” said Alan Stern, the team’s principal investigator from the Southwest Research Institute. “We haven’t found geysers and we haven’t found cryovolcanoes, but this is very strong evidence that will send us looking … for evidence of these exact phenomena.”

This is just the tip of the iceberg for Pluto. There are more questions than answers at this point. But a couple of things are clear: These preliminary images of Pluto have far exceeded the expectations of the team — and there’s still a lot more to learn about this icy yet surprisingly youthful world.

NOW WATCH: Bill Nye and NASA scientists react to seeing a clear picture of Pluto for the first time

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