After a 9-and-a-half year voyage, the New Horizons space probe recently got up close and personal with Pluto—the former planet, now known as a dwarf planet, that resides over 4 billion miles from Earth.
When the New Horizons mission began, NASA (National Aeronautics and Space Administration) had visited all other planets in the Solar System—Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. “The goal of New Horizons was to complete the tour of all the planets,” said Tom Willmitch, the director of Illinois State University’s planetarium.
Scientists are realizing the Solar System is much more complex than they thought it was 30 years ago, or even at the time the New Horizons mission launched in 2006 to visit Pluto when it was still considered a planet. Later that same year, Pluto was reclassified as a dwarf planet and officially became part of the Kuiper Belt. “It’s a massive asteroid belt that 40 years ago we could only speculate whether it existed or not, now we know it does,” explained Willmitch.
Although there was always speculation that Pluto was one of the smallest dwarf planets, “thanks to New Horizons, we now know Pluto is the largest of five dwarf planets within the Kuiper Belt,” noted Willmitch.
The space probe has now passed Pluto and is heading further into the Kuiper Belt. It’s a huge step forward in understanding the region beyond Pluto.
This mission is giving scientists a look into the Kuiper Belt, which is far more massive than the Asteroid Belt—the region of the Solar System between Mars and Jupiter. “The pieces of rock and ice that are out there are pristine stuff,” said Willmitch. “We are looking at this deep freeze that contains the basic ingredients from when the Solar System formed, including the chemicals that eventually ended up leading to life on our world.”
There are some big mysteries with the Kuiper Belt—there are a number of objects that don’t even have names, just catalog numbers. “There are objects out there—small tiny worlds, smaller than Pluto that we can’t explain why they are there – we can’t come up with a good scenario that explains them,” said Willmitch. “There are some big mysteries in the Kuiper Belt. Just getting out there and seeing what’s there is the first step.”
The space probe is traveling at 35,000 miles per hour—fast enough that one could travel from New York to Los Angeles in four minutes. It’s pulling about 30 watts of power from the nuclear reactor utilizing plutonium that produces the energy for New Horizons. There are massive radio-dishes picking up the pictures being sent back, which take four hours to reach Earth. There are a series of these tracking stations around the world constantly picking up the signal.
There are lots of missions always taking place and scientists can’t even speculate what might be found in the Kuiper Belt or beyond. “You endlessly discover things you never expected during these missions,” said Willmitch. “The more of those we find, the more fascinating it makes the Solar System.”
One thing that is known—the spirit of Central Illinois travels with New Horizons. “A few of the ashes of Clyde Tombaugh, the man who discovered Pluto in 1930, are on the New Horizons voyage,” said Willmitch, noting Tombaugh was a native of nearby Streator. A close connection to an object millions of miles away.
