In 2006, the International Astronomical Union downgraded Pluto. From 1930, when it was discovered, until Pluto’s fall from grace 76 years later, earthlings were taught that their solar system consisted of nine planets. Suddenly, they faced a brave new world of only eight planets, plus dwarf Pluto 3.6 billion miles from the sun and innumerable others beyond.

For those who despaired of what may have been a rush to judgment regarding Pluto’s status, there is reason to take heart. News reports late last week said that scientists from the Harvard-Smithsonian Center for Astrophysics have begun pushing back on the notion that Pluto is a dwarf.

A planet must orbit the sun, have sufficient mass to assume a round shape and “clear its neighborhood” of space rocks in its path as it continues to orbit.

Scientists who argued for Pluto’s demotion said its strange interaction with nearby Neptune sometimes makes it act more like an eccentric moon than a stand-alone planet. Still, a few prominent scientists argue that earthly politics played too big a role in the decision to give Pluto second-rate status.

Next July, the New Horizons spacecraft will do the first flyby of Pluto, gathering unprecedented data and images of that distant world. The mission will go a long way, we hope, toward settling the debate over whether Pluto is a planet or something less.

Copy the Story Link