Pluto, King of the Outer Worlds

New measurements from NASA’s New Horizons spacecraft revealed that Pluto, named for the Greco-Roman god once called Hades, is a little more swollen with ice than previously thought, making it the biggest trans-Neptunian object—more voluminous than rival dwarf planet Eris, which is nevertheless more massive. Greg Laden explains why these orbs are not considered full-fledged planets on his blog.

While Eris orbits the Sun within the ‘scattered disc,’ Pluto orbits in the Kuiper Belt, a collection of gravelly snowballs that Ethan Siegel says outnumber all the planets in our galaxy. The Kuiper Belt begins beyond Neptune, encircling all the planets in our solar system and extending outward for a distance equal to the gap between the Sun and Uranus. It took New Horizons more than nine years to fly to Pluto from Earth, after setting a record for highest launch speed of any man-made object, after getting a massive speed boost from the gravity of Jupiter, and without any need to slow back down. It will now take sixteen months for New Horizons to stream all the scientific data from its brief flyby of Pluto back to Earth. Meanwhile the spacecraft will attempt to visit another smaller Kuiper Belt object before it runs out of fuel and falls short of the edge of our solar system.

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New Chimp Status and Strategic Swine

As researchers continue to document the intelligence and emotional acuity of animals, beasts begin to look more like brethren, and food more like friend. On Pharyngula, PZ Myers shares a decision by the U.S. Fish and Wildlife Service that gives chimpanzees used in research the same endangered status as their wild cousins. According to Science, “organizations that want to continue working with chimpanzees will have to document that the work enhances the survival of the species and benefits chimps in the wild.” PZ writes, “I want to see more studies done on our closest relatives — but it has to be done in a way that respects their right to live.” Meanwhile, Greg Laden considers commonalities humans share with one of our preferred sources of animal protein—pigs. A new review of past swine research emphasizes that pigs have excellent long-term memories, comprehend simple symbols, demonstrate empathy, and are very social: they play with, help, and even deceive each other. Greg stresses that pig-human similarity is qualitatively different from chimp-human similarity, resulting not from close ancestry, but from parallel evolutionary histories—including an affinity for eating roots.