Once launched in 2021, NASA’s long-awaited James Webb Space Telescope (JWST) will spend the first few months of operations focusing in part on Pluto, its moon Charon and a panoply of other bizarre, frozen worlds in the planetary graveyard of our outer solar system.
NASA’s New Horizons spacecraft’s magnificent 2015 flyby of the dwarf planet Pluto, and its moon Charon, revealed that these objects are far more active and far more interesting than previously thought. In fact, Pluto and Charon arguably act as gatekeepers to an outer region of our solar system that is made up of thousands of dwarf planets and other relatively small objects.
“These are objects that are in the graveyard of solar system formation,” Cornell University’s Jonathan Lunine, a Webb Interdisciplinary Scientist who will use Webb to study some of these targets, said in a statement. “They’re in a place where they could last for billions of years, and there aren’t many places like that in our solar system. We’d love to know what they’re like.”
So-called Kuiper Belt Objects, objects that lie in a circumstellar disk of planetary leftovers extending from beyond Neptune to some 50 Earth-Sun distances, are inherently cold and faint. Yet because they glow in infrared light, at wavelengths Webb is specifically designed to detect, the telescope should be extremely adept at detecting such bodies’ wide range of colors, says NASA. This, in turn, should provide clues as to their formation histories.
And while JWST can’t get the very close up images that New Horizons provided, it provides a different way at getting at the composition, Lunine told me.
These objects include Eris, the second-largest dwarf planet in our solar system. Nearly the size of Pluto, at its farthest point, mysterious Eris is more than 97 times as far from the Sun as the Earth is, says NASA. But as part of its guaranteed time observations, Webb should provide lots of data about what types of ices cling to its surface. Another, Sedna, is so far distant that it takes some 11,400 years to complete one orbit around our Sun, says NASA. And a strange 250-km asteroid Chariklo is the