Pluto’s icy, slushy heart
Beneath Pluto’s “heart” lies a cold, slushy ocean of water ice, according to data from NASA’s New Horizons mission. In a paper published today in the journal Nature, the New Horizons team, including researchers from MIT, reports that the dwarf planet’s most prominent surface feature — a heart-shaped region named Tombaugh Regio — may harbor a bulging, viscous, liquid ocean just below its surface. The existence of a subsurface ocean may solve a longstanding puzzle: For decades, astronomers have observed that Tombaugh Regio, which is Pluto’s brightest region, aligns almost exactly opposite from the dwarf planet’s moon, Charon, in a locked orientation that has lacked a convincing explanation. A thick, heavy ocean, the new data suggest, may have served as a “gravitational anomaly,” or weight, which would factor heavily in Pluto and Charon’s gravitational tug-of-war. Over millions of years, the planet would have spun around, aligning its subsurface ocean and the heart-shaped...