New Mexico astronomer Clyde Tombaugh discovered Pluto accidentally in 1930. I had the pleasure of meeting and chatting with Tombaugh in 1977 at a meeting of the Lehigh Valley Amateur Astronomical Society in Allentown, Pa. Tombaugh was a gentle and humble man.
I think Tombaugh would be proud of NASA's New Horizons mission to reach this smallest of planets. Sadly, it is probably one of NASA's final great interplanetary missions; the space agency is currently being gutted by the clearly anti-space Obama regime. NASA's peaceful mission to explore the cosmos has never been more uncertain and a U.S. president has never been more hostile to the space-science community.
NASA's New Horizons robot spacecraft is on its nine-year deep-space voyage to the planet Pluto-ok, dwarf planet or KBO (Kuiper Belt Object) or-whatever current buzz word you want to slug this fascinating world.
The plutonium-powered spacecraft, traveling at 47,000 mph, will flyby chilly Pluto five years from now-July 2015. If successful, it will be the first humanmade object ever to reach Pluto approximately 3 billion miles from Earth. Pluto is the farthest, large planetary body from our Sun. Occasionally, Pluto gives up this position to Neptune due to the unusual, elliptical Plutonian orbit. A year on Pluto lasts 248 terrestrial years.
In 2000, after scrubbing its Pluto Fast Flyby, later renamed Kuiper-Pluto Express mission, space agency officials were forced to reconsider their mistake when many scientists and vocal pro-space groups protested loudly. "We have to get to Pluto quickly," the experts claimed. So, from the ashes of the PFF/KPE mission was born New Horizons. But what's the hurry and why should we visit Pluto now, you may ask?
As it moves away from the Sun, Pluto's atmosphere will re-freeze falling to the surface as a nitrogen-carbon dioxide-methane snow sometime around the year 2020. Hence, scientists are anxious to get to Pluto now, while it still has a gaseous atmosphere. Missing the January-February 2006 launch date would have meant waiting until the year 2200 when Pluto's long-sleeping atmosphere sublimes back from ice to gas.
What will we find when we finally visit Pluto?
Being almost 6 billion km from the Sun, the rock and ice-bound planet's surface must be terribly cold, colder than liquid nitrogen. Estimates place Pluto's surface at a cryogenically chilly minus 396 degrees Fahrenheit. That's cold enough for water ice to act like rock. But the warmer interior protected by miles of thick nitrogen, methane and carbon monoxide ices, and heated by radioactive rocks at the planet's core, may support a deep layer of liquid water-a Plutonian ocean. It's fun to speculate what life forms might have evolved in that Stygian sea.
Any future astronauts landing on Pluto will stand on the frontier of the solar system. They will see the dwarf planet's cratered moon Charon looming large in the sky. Inward, toward the Sun, our feeble home star will appear much like Venus does from Earth. There will be no warmth from its rays. Outward, the explorers will gaze into the immense gulf of interstellar space.
What's in the Sky: A full Moon occurs July 25 at 9:36 p.m. On July 27, look for the elusive planet Mercury at dusk in the west. Mercury is to the lower left of the star Regulus about 25-30 minutes after sunset. All you need are binoculars to get a glimpse of the hot little planet.
Lou Varricchio, M.Sc., is a former science writer at the NASA Ames Research Center in California. He is Vermont's NASA-JPL Solar System Ambassador and a recipient of the U.S. Civil Air Patrol's Gen. Chuck Yeager Aerospace Education Achievement Award.