Today, NASA’s New Horizons spacecraft will sweep past Pluto and present the previously unexplored world in all its icy glory.
New Horizons has traveled 3 billion miles over 9½ years to get to this historic point. The fastest spacecraft ever launched. The size of a baby grand piano, the spacecraft came closest to Pluto today — at 7:49 a.m. EDT. That’s when New Horizons was predicted to pass within 7,767 miles of Pluto. New Horizons left Earth in 2006 at a speed of 36,000 miles per hour on a mission to study Pluto and its moons. As it has neared the dwarf planet, the probe has been sending back increasingly clearer images of its target. And in a cosmic coincidence, the Pluto visit falls on the 50th anniversary of the first-ever flyby of Mars, by Mariner 4. The Hubble Space Telescope previously captured the best pictures of Pluto.
New Horizons, weighing less than 1,000 pounds including fuel, has seven instruments that will be going full force during the encounter. It’s expected to collect 5,000 times as much data, for instance, as Mariner 4.
The only planet in our solar system discovered by an American, Pluto actually is a mini solar system unto itself. Pluto — just two-thirds the size of our own moon — has big moon Charon that’s just over half its size, as well as baby moons Styx, Nix, Hydra, Kerberos and Styx. The names are associated with the underworld in which the mythological god, Pluto, reigned. New Horizons will observe each known moon and keep a lookout for more. In 2006, Pluto was demoted from a full planet to a dwarf planet — because if Pluto remained a planet, lots of similar-sized bodies on the edge of the solar system would have to be considered as planets too.
With its tilted, elongated 248-year orbit, Pluto has made it only a third of the way around the sun since its discovery.
Scientists won’t be absolutely certain of success until tonight, 13 hours following New Horizons’ closest approach, when it “phones home.” Photos taken during the flyby will be beamed back to Earth.
The exploration of Pluto and its moons by New Horizons represents the capstone event to 50 years of planetary exploration by NASA and the United States.
sources: foxnews.com, cnet.com, solarsystem.nasa.gov