Pluto was once considered one of the solar system’s planets but was later downgraded to the status of ‘dwarf’ planet after several more similarly sized objects were discovered throughout our solar system. Without this categorization change, the list of known planets would have become substantially longer, and more difficult to keep track of.
Astronomers have had an interest in Pluto for decades, but it wasn’t until NASA’s New Horizons mission that we were finally able to photograph the small world’s intriguing surface great detail. These images depicted a chilly world comprised of ice and rock, with the icy bits containing frozen carbon monoxide, methane, and even nitrogen.
Because of Pluto’s small size, which hardly more than half of the width of the contiguous United States, the world sports a particularly weak gravitational pull that is approximately 6% that of the Earth’s. This gentile tug is enough for Pluto to sport an atmosphere, but a relatively thin one at that, and one that stretches far into outer space.
While Pluto doesn’t have much gravitational influence to speak of, that hasn’t stopped it from collecting its far share of moons over the years as it passes through the Kuiper belt. Pluto sports five known moons, including Charon, Hydra, Kerberos, Nix, and Styx, with Charon being the largest at half of the size of Pluto itself.
There’s no telling when another spacecraft will visit Pluto to learn more about its unique characteristics, but given just how long it takes to venture out there, we can only hope that time will come sooner rather than later such that we can all bear witness to it.