ST. LOUIS, Mo. – Pluto was downgraded from a planet nearly 15 years ago. But, you may have forgotten that you can call it a planet when observed from Illinois.
Pluto discovery day is on March 13. An Illinois man named Clyde Tombaugh working as a researcher at the Lowell Observatory in Flagstaff, Arizona detected the object in 1930.
For more than 75 years Pluto was considered a planet. The International Astronomical Union updated the rules for what is and what isn’t a planet in 2006.
The IAU defined a planet as a celestial body that orbits the sun, is round or nearly round and “clears the neighborhood” around its orbit.
The IAU said Pluto was just too small to clear the neighborhood or knock other space rocks out of its path as it orbits the sun. And so, the astronomical union demoted Pluto to dwarf planet status.
The debate of whether Pluto is a planet or not flares up from time to time. The astronomer who discovered the object was born in Illinois and his home state is very proud of that fact. Tombaugh was born on a farm near Streator.
So, the Illinois Senate declared Pluto a planet in 2009. Here is their reasoning that is included in Senate Resolution 46:
“In a vote in which only 4 percent of the International Astronomical Union’s 10,000 scientists participated; and Many respected astronomers believe Pluto’s full planetary status should be restored; therefore, be it resolved, by the senate of the ninety-sixth general assembly of the state of Illinois, that as Pluto passes overhead through Illinois’ night skies, that it be reestablished with full planetary status, and that March 13, 2009 be declared “Pluto Day” in the State of Illinois in honor of the date its discovery was announced in 1930.”
In 2015 NASA’s New Horizons spacecraft completed a historic flyby of Pluto becoming the first spacecraft to pass over the small, icy world.