Chasing Pluto

Discovered in 1930, the planet Pluto is considered a scrappy underdog. About 10 years ago, astronomers unceremoniously declared that Pluto was not a planet after all, or rather a "dwarf planet" in the Kuiper belt, which is home to many rocky, icy objects—frozen remnants dating back to the formation of the solar system. Directed by Terri Randall, this PBS-aired NOVA documentary looks at a nine-year space odyssey to learn more about this obscure celestial body that takes 200 years to orbit the Sun. Pluto is so distant it previously could only be depicted in artwork—unable to be clearly seen even by the powerful Hubble telescope. In 2006, the surprisingly compact New Horizons space probe was launched on an epic journey to Pluto, which is located some three billion miles from Earth. Moving at a speed of 30,000 miles per hour, New Horizons received a boost from the gravity of Jupiter (somewhat similar to the "whip" movement in roller derby). Space officials back on Earth had plenty of anxious moments waiting for signals, worrying that some bit of space debris could strike and disable the expensive probe. Aside from weekly check-ins, New Horizons was "asleep" for most of the journey, in an attempt to save power and wear. Finally, in 2015, the probe reached Pluto, transmitting pictures of an icy, crater-pocked surface, with mountain ranges up to 11,000 feet high. Although life as we know it is hardly possible in an atmosphere of extreme temperatures with elements of nitrogen, methane, and carbon monoxide, some scientists do speculate that a vast ocean could be found in Pluto's interior. Although not a candidate for human exploration, Pluto (reinstated to “planet” status in 2014)—with its five moons and unique atmosphere—has much to tell us about the mysteries of outer space. Recommended. Aud: H, C, P. (S. Rees)