Just a few hours ago, NASA has released the first of several images taken by New Horizons' during its close encounter with dwarf planet Pluto. And they are, in a word, stunning. The images comprise a high-res sight of a small area on Pluto, in which mountains made of water ice rise 11,000 feet above what seems to be a young, lively surface. Charon, Pluto’s biggest moon, has also appeared in astonishing detail. And then there’s also the first image of Hydra, one of the system’s four tiny moons. New Horizons principal investigator Alan Stern, says “I think the whole system is amazing. This system is something wonderful.” Early on July 14, the New Horizons spacecraft flew past Pluto and its five identified moons, coming within 8,000 miles of the ice-covered dwarf planet. Now that Pluto is in the spacecraft’s past, the group is starting to dig through the river of data New Horizons will send to Earth over the next nearly 16 months. Those observations, the first of which reached at 5:50 a.m. on July 15, comprise information about Pluto’s atmosphere and configuration, and the system’s four small moons.
|Mountains made from water ice rise 11,000 feet (3,500 meters) above Pluto’s surface. PHOTOGRAPH BY NASA-JHUAPL-SWRI|
Initial images indicated that Pluto is a mottled, champagne-colored sphere that doesn’t look like anything else in the entire solar system—even if its reddish shade does slightly resemble Mars. Pluto's surface, which we’ve been questioning about for 85 years, is distinctive. The world is concealed in radically different lands, some smooth, some cratered and rough. The recent Pluto image discloses a region of the planet with huge mountains coming up over a surface that looks quite young—so young, actually, that it proposes the planet is still geologically active. Pluto team member John Spencer, says “We have not yet found a single impact crater on this image. Pluto has been bombarded by other objects in the Kuiper Belt. Craters happen. We think it probably has to be less than 100 million years old—it might be active right now.”
Pluto also differs in brightness. Smeared near the planet’s equator is a really bright, heart-shaped area the group is now informally calling Tombaugh Regio, after the man who discovered Pluto back in 1930. Stern said “We could see the heart very far from Pluto. You could see that shining like a beacon. That’s why we want to call it Tombaugh Regio.”
Squeezing that heart on either side are marks that are about as dark as anything can get. The heart’s halves seem to be made from different constituents, but the team doesn’t yet comprehend the geology of the whole area. Pluto team member Will Grundy of Lowell Observatory, said “It’s kind of a coincidence that these things have similar [brightness],”
It’s also not clear why the heart seems to be so flat, or “absurdly featureless,” as Spencer called it. Reviewing its borders should provide a clue about what’s going on, and whether the smoother lands are high or sunken.
The Moon Dance
And then there’s mighty Charon, Pluto’s largest moon. Stern said “Pluto and Charon look very different. Now we can see how dramatically different they really are.”
Together, the two bodies make a binary planet. They rotation around a point in the space between them, performing a cosmic dance in which they continually gaze at one another. While researchers expected Charon to be exciting, they weren’t ready for the image that came back today.
|With its dark pole and cracked surface, Pluto’s large moon Charon had a few surprises in store for the New Horizons team. PHOTOGRAPH BY NASA-JHUAPL-SWRI|
Deputy project scientist Cathy Olkin, said “It’s a small world with deep canyons, troughs, cliffs, dark regions that are still slightly mysterious to us. There is so much interesting science going on in this image alone.”
Charon has a mysterious dark pole that could be made of constituents that fled from Pluto. Group members are informally calling that area as Morder, Olkin said.
The moon has also cracks—and few of those cracks are huge, as much as five or six miles deep. What’s more, the moon’s surface appears astonishingly young, signifying that it might also be an active world.
Researchers think Charon formed from a huge impact with prehistoric Pluto, and that debris from the impact ultimately merged and formed the pair’s four smaller moons, called Nix, Hydra, Kerberos, and Styx.
Hydra has now been observed for the first time, however it still looks like a pixelated splash. But group members were still able to figure out that the moon is 45 kilometers long.
Pluto's four moons were lately discovered to be wildly rotating—in other words, they’re dropping in orbit rather thin spinning. Overall, the Pluto system is like a complex, contracted planetary system, and researchers hope that by cracking Pluto’s secrets, they’ll acquire more knowledge about how planetary systems form and develop.