A watercolor rendition of the dwarf planet Pluto. What do you think it might look like?
Pluto revolves around the Sun in an orbit that is not exactly circular, much like the rest of the planets. Rather, its orbit is more of an oval or egg shape. Because of this, Pluto will orbit inside of Neptune’s orbit. At times, this makes Pluto closer to the Sun than Neptune. Also, its orbit does not lie flat in the same plane as the rest of the planets. Pluto’s orbit tilts so it orbits above and below the other planets’ orbits in our Solar System. Scientists believe Pluto is about two-thirds rock and one-third water ice. There might actually be more water on Pluto than on Earth. Like Neptune, Pluto was discovered through mathematical predictions instead of observation.
In 1906 Percival Lowell started the search for the planet X. He believed that another planet must exist that he could find with mathematics. Unfortunately, he died before finding Pluto. Pluto wasn’t discovered until 1930 by Clyde Tombaugh. He was working at the observatory of Percival Lowell and reviewing his previous work. Clyde Tombaugh discovered the planet after a year of searching.
Pluto is the Roman god of the underworld. He is the brother of Neptune and Jupiter. In Greek mythology, he’s counterpart is Hades.
Pluto was given its name by an 11-year-old girl! Her name was Venetia Burney, who lived in Oxford, England. When they discovered the planet in 1930, she said they should name it after the Roman god of the underworld. Venetia’s grandfather sent this suggestion to the Lowell Observatory. And that’s how Pluto got its name.
How much would you weigh on Pluto?
Because Pluto is so small you would be very light if you visited. If you weigh 70 pounds (32 kg) on Earth, you would only weigh 4 pounds (2.5 kg) on Pluto. The planet’s gravity is super weak!
Pluto and its moon Charon.
The Dwarf Planet
Pluto is smaller than 7 of the moons in the Solar System. It is about two-thirds smaller than Earth’s moon. Because it is so small, many scientists don’t consider it a planet at all. In 1999, a group of scientists attempted to re-classify Pluto as a comet. On August 24, 2006, Pluto’s status was officially changed from planet to dwarf planet. Pluto had previously been a planet for 75 years. For decades, children were taught in school that there are nine planets in our Solar System. However, with this change, there are now only eight official planets.
Even More Dwarf Planets
What brought about this new status was the discovery of other dwarf planets. Beginning in 1992, scientists discovered other dwarf planets orbiting in the same area as Pluto. Today scientists have discovered more than a thousand objects in this area. With these discoveries, there was a new category created called the plutoids. Pluto is the largest of the dwarf planets.
These plutoids are in an area that scientists have named the Kuiper Belt. This belt likely consists of mostly icy materials. The discovery of Eris, another dwarf planet sparked the discussion, what makes a planet a planet?
The Hubble Space Telescope has provided the clearest images of Pluto for scientists. Studies of Pluto and its moons are still conducted today with these images. However, little is still known about Pluto and its moons because it is so far away.
This planet has 5 moons. The largest is Charon. Charon is only slightly smaller than its parent Pluto. For this reason, Pluto and Charon are often called a double planet system. The Earth and its moon, Luna, are sometimes considered double planets. Pluto’s moons are Hydra, Styx, Kerberos and Nix.
Pluto’s moons, many were just discovered in the past 18 years.