Marc William Buie is an American astronomer and prolific discoverer of minor planets who works at the Southwest Research Institute in Boulder, Colorado in the Space Science Department. Formerly he worked at the Lowell Observatory in Flagstaff, Arizona, and was the Sentinel Space Telescope Mission Scientist for the B612 Foundation, which is dedicated to protecting Earth from asteroid impact events.
Buie in 2013
Buie in July 2017 leading the occultation campaign to observe 486958 Arrokoth before the New Horizons fly-by of the Kuiper belt object in January 2019.
Pluto is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known trans-Neptunian object by volume, by a small margin, but is less massive than Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Pluto has roughly one-sixth the mass of Earth's moon, and one-third its volume.
Pluto, imaged by the New Horizons spacecraft, July 2015. The most prominent feature in the image, the bright, youthful plains of Tombaugh Regio and Sputnik Planitia, can be seen at right. It contrasts the darker, cratered terrain of Belton Regio at lower left
Clyde Tombaugh, in Kansas
Sputnik Planitia is covered with churning nitrogen ice "cells" that are geologically young and turning over due to convection.
Multispectral Visual Imaging Camera image of Pluto in enhanced color to bring out differences in surface composition.