 Four days after the airing of this space pod, one of the most enigmatic and distant objects in the solar system will have all of its secrets revealed. Pluto has been a mystery to astronomers in the 85 years since its discovery, and NASA's new horizon probe is about to reveal everything. This is your space pod for July 10, 2015. For something less than the size of the continental United States, Pluto's recent history is marred in quite a bit of controversy, but if we're going to talk about Pluto's history, we actually first have to look at Uranus under the telescope. Through the use of Newtonian mechanics, it was discovered that there were perturbations in Uranus' orbit. After Neptune was discovered and its mass calculated, it was speculated that a larger object was needed to explain these, and the hypothesis of Planet X was born. In 1894, Percival Lowell, a businessman and astronomer, founded the Lowell Observatory in Flagstaff, Arizona, and in 1906, Lowell commenced a search for Planet X in Uranus. The observatory conducted this search for nearly a decade until Lowell passed away in 1916. Another decade would pass due to Lowell's widow attempting to seize the observatory's assets. The search finally resumed in 1929, and a 23-year-old fresh astronomer named Clyde Tombaugh was given the task. The discovery of the potential Planet X occurred on the 18th of February 1930, only a year into Tombaugh's survey. Using a blink comparator to rapidly switch between two plates exposed on the 23rd and 28th of January, a small speck was seen moving across the static stars behind it. After more imagery was obtained, a telegraph announcing the discovery of this new distant world was sent to the Harvard College Observatory on the 13th of March 1930. It immediately made global headlines, and Tombaugh was an overnight celebrity. Tombaugh advocated for a name to be assigned to the object quickly, and several were considered, but one from an 11-year-old schoolgirl from Oxford, England, Venetia Burry, became the leading contender amongst the astronomers, Pluto, the Roman god of the underworld. The official naming occurred on March 24, 1930 at Lowell Observatory. There were three choices for the astronomers, Minerva, Chronos, and Pluto. A vote was taken, and the result was unanimous. Pluto would be its name. Venetia was given 5 pounds, or the equivalent of 430 US dollars for her name's suggestion. Pluto resonated with Lowell Observatory because Pluto's first two letters, P and L, are the initials of Percival Lowell. The difficulty in resolving Pluto is anything but a small speck made study of it extremely difficult. Initially thought to have a mass near Earth, in 1948 this was revised downwards to about the mass of Mars, then revised further downwards in 1976 to no larger than one one-hundredth the mass of Earth. A surprising discovery occurred in 1978, Pluto had a moon, named Sharon after the ferryman of the dead. This allowed for an extremely precise measurement of Pluto's mass, and once again, down it went, this time to one-fifth the mass of the Earth. Decisions by the Hubble Space Telescope have helped us resolve Pluto and Sharon, and several more moons have been found in orbit around Pluto. We even got some detail from Pluto's surface. In 2006, a controversial decision was approved to downgrade Pluto from a major planet to a minor planet, what can also be called a dwarf planet. This was prompted by the discovery of other objects in the solar system that may be similar to Pluto, but we'll talk about that in greater detail during next week's space pod. But now it's New Horizons time to shine. Launched in January 2006, the flyby is set for July 14th, just about twelve thousand five hundred kilometers above the surface, aiming to gain understanding into the geology and morphology of Pluto and Sharon, their surface composition, and the atmosphere that may still be lingering around Pluto. This is the latest photo as of the airing of this space pod, a complex looking little place. And with our exploration of the plutonium system, an era of space exploration of our solar system will finally come to an end. Thanks for watching this space pod. I'm Jared Head. If you'd like to monitor NASA's New Horizons probe as it's currently on approach to Pluto, you can actually go to Pluto.jhuapl.edu. There you can get the latest imagery and updates from the New Horizons team. Also, don't forget to like, comment, and subscribe to us on social media. And a special thank you to all of our patrons on our Patreon page. We're very glad to have you on board with our space pods here. And we hope that you'll contribute to help spread the universe to everyone. Next week, we'll be talking specifically about that controversy involving Pluto and its downgrade in its planetary status. So, until our next space pod, keep exploring.