The Charon photo, above, was snapped when New Horizons was just 49,000 miles away, back on July 14th when the probe was around 90 minutes from its closest pass by Pluto.
John Spencer, like Stern a scientist at the Southwest Research Institute, called it “just astonishing” that the first close-up picture of Pluto didn’t have a single impact crater. It’s smaller than our own moon, and it orbits at an angle relative to the plane of the solar system. This suggests that Pluto may be younger than scientists initially believed and that a lot of geological activity has recently smoothed its surface, according to The Washington Post.
“The mountains on Pluto likely formed no more than 100 million years ago – mere youngsters in a 4.56-billion-year-old Solar System”, NASA scientists say.
Unlike the icy moons of giant planets, Pluto can’t be heated by gravitational interactions with a much larger planetary body.
“This deep topography means that the bedrock that made these mountains must be H2O-of water ice”.
“At Pluto’s temperatures, water-ice behaves more like rock”, said Bill McKinnon, deputy lead scientist with New Horizon’s Geology and Geophysics Imaging team. The image’s resolution can resolve surface features less than one mile wide.
The agency described the depression as Charon’s “Mountain in a Moat” in a tweet on Thursday, noting that the image is a preview of future closeups.
A stunning Charon image was also released, clearly showing a swath of cliffs and troughs stretching about 600 miles across the moon’s surface. New Horizons swept to within 7,700 miles (12,391 kilometers) of Pluto during its flyby.
In addition to Charon, Pluto is also orbited by Hydra, its outermost moon.
The latest spectra from New Horizons Ralph instrument reveal an abundance of methane ice, but with striking differences from place to place across the frozen surface of Pluto.
Charon’s images were taken along with the dwarf planet, as well as its four smaller moons: Nix, Hydra, Styx and Kerberos.
The mission’s principal investigator, Alan Stern, said the heart-shaped region, the brightest part of the dwarf planet, had been named “Tombaugh Reggio”, after Clyde Tombaugh, who discovered the planet in 1930.