Pluto: Dwarf Planet and New Horizon
85 years ago, American astronomer Clyde Tombaugh discovered Pluto: a distant, frozen, tiny rocky planet that quickly became the 9th planet of our solar system. It held this position for 76 years until it was demoted to "Dwarf Planet" (or "Plutoid") in 2006.
In 2005, astronomer Dan Brown--not to be confused with "The DaVinci Code" author of the same name--made a huge discovery: a planet orbiting beyond Pluto that it may actually bigger! Was this the 10th planet of our solar system?
There seemed to be many objects in our solar system about the size of Pluto! Orcus, Haumea, Quaoar, Makemake, Eris, Ceres, and Sedna to name the ones we've found so far. Were these all planets? Our solar system was about to become a crowded place.
Even though Pluto is a Dwarf Planet now, it has become something more - our New Horizon.
But in 2006 the International Astronomical Union put a stop to all of this planet talk and re-defined what it meant to be a "planet." Sadly, Pluto was demoted to "Dwarf Planet" or "Plutoid" because of this ruling, and our solar system which stood on the brink of containing 16 planets, was shaved down to just 8.
And just this month, a NASA space probe named "New Horizons" whipped past Pluto after a ten year trek and captured the first images of the Planet. They found one of the youngest surfaces in the solar system, a geologically alive world, and one that was full of surprises (they found mountains of frozen water ice!).
And we measured the dwarf planet exactly: it is the biggest known object in the Kuiper Belt. Take that Eris.
I love that we are still discovering, and still learning! Still, there are those of us that learned growing up that our solar system had 9 planets. Even though Pluto is a Dwarf Planet now, it has become something more - our New Horizon. It is the gateway to our solar system's third zone, the Kuiper Belt.
Pluto used to be the end. Now it's the beginning. It's like the little planet that could.