© SWRI, JHUAPL, NASAOUT-OF-THIS-WORLD LANDSCAPE The latest data from the New Horizons mission has helped create topographical maps of Pluto (blue shows lower elevations, brown, higher elevations) that have revealed surprises such as these two possible ice volcanoes, the first of their kind in the outer solar system.
Spinning moons, possible ice volcanoes detected on dwarf planetAt this point, the only thing unsurprising about Pluto is that it continues to offer up surprises. A wide variety of landscapes, ongoing surface transformations and a family of wildly spinning moons are among the riddles reported by the New Horizons mission team November 9 at a meeting of the American Astronomical Society's Division for Planetary Sciences.
Terrains both new and old sit side-by-side on Pluto's surface.
Some heavily cratered regions are roughly 4 billion years old, about as old as Pluto itself. Others, like the now famous heart, appear to have been laid down within the last 10 million years, judging by the total lack of craters. Two mountains look strangely similar to shield volcanoes back on Earth. On Pluto, though, the
volcanoes would spew ice, not rock. "There's nothing like this seen in the outer solar system," says Oliver White, a planetary scientist at the NASA Ames Research Center in Moffett Field, Calif. The mountains aren't definitely volcanoes, but researchers aren't sure what else to call them. "Whatever they are, they're definitely weird," says White.
Whirling far above Pluto, four tiny satellites — Nix, Hydra, Kerberos and Styx — are also behaving unexpectedly (
SN Online: 11/2/15). Pluto's gravity should have slammed on the brakes and slowed down their spins. But the
rapidly twirling moons seem to be unfazed.
Hydra, the outermost moon, whips around its axis about 89 times during each loop around Pluto and Charon. Nix, meanwhile, appears to be flipped nearly upside down while the other three tiny moons might be spinning on their sides. "This is unprecedented," says planetary scientist Mark Showalter of the SETI Institute in Mountain View, Calif., who discovered Kerberos and Styx several years after New Horizons launched. "We've never seen anything like this before, and we still don't know what to make of it."
Published on Nov 9, 2015
Most inner moons in the solar system keep one face pointed toward their central planet; this animation shows that certainly isn't the case with the small moons of Pluto, which behave like spinning tops. Pluto is shown at center with, in order, from smaller to wider orbit: Charon, Styx, Nix, Kerberos, Hydra.
Comment: Your stressful job may kill you -- especially if you're a woman