By The Adler Planetarium
Since it’s discovery, and 10 years after its reclassification to dwarf planet, Pluto is still plagued by its lack of true planet status. This begs the question, if Pluto isn’t a planet, then what is? What made the International Astronomical Union reclassify Pluto in 2006? On March 19th, the Adler Planetarium will be opening their newest temporary exhibition, What Is a Planet?, which explores the answers to these very questions.
The accepted definition of a planet has changed quite a bit over the past 500 years. At various moments the term has been used to describe the Sun, the Moon, and asteroids. And would you believe that Earth – the most familiar planet of all – hasn’t always been considered a planet?!
Posted on March 8, 2016