Although technically a dwarf planet since 2006, Pluto still holds a large, special place in our hearts as a beloved member of our solar system. What is a dwarf planet, exactly? According to the International Astronomy Union, a dwarf planet is similar to a planet in that it orbits the Sun and its mass is sufficient enough that its gravity forms it into a (usually) spheroid shape. Unlike a planet, however, a dwarf planet has not “cleared the neighbourhood around its orbit,” meaning that it is not gravitationally dominant in its vicinity. It also must not be a satellite, or an object orbiting another large body. Since Pluto did not meet the “clearing the neighborhood” requirement, the scientific community demoted it in August 2006.
Clyde Tombaugh officially discovered Pluto in 1930; however, the scientific community generally credits Percival Lowell as a player in the planet’s discovery, despite passing away 14 years before its discovery. In particular, Lowell proposed the existence of a Planet X, a planet beyond Neptune. Tombaugh began searching for this Planet X, discovering Pluto as a result of his research (although it is generally accepted that it is a coincidence that Pluto is close to the hypothetical Planet X, with the general consensus being that Pluto is not Lowell’s Planet X). Since its discovery, Pluto has become widely incorporated into pop culture. Did you know, for instance, that Walt Disney apparently named Mickey Mouse’s dog after the planet, rather than the Roman god of the dead?
Many of the incredible photos we have of Pluto come from NASA’s New Horizons mission, which began in 2006 with the launching of the New Horizons satellite. Its flyby mission required it to get closer to Pluto than we ever have before and capture images of it. We’ve since learned much about our favorite dwarf planet, like that it possibly has ice volcanoes on its surface. We’ve gathered some of the best photos of Pluto to celebrate this fascinating celestial body.
Here we have a lovely look at the “majestic mountains and frozen plains” of Pluto. Did you know that Pluto is composed of nitrogen, methane, and carbon monoxide?
This image shows the informally named al-Idrisi mountains. Did you know that Pluto is the largest object in the Kuiper belt?
NASA claims that Pluto constantly renews its icy surface via convection. The scene from this image above is roughly 250 mi (400 km) across!
Jupiter has its Great Red Spot, Pluto has its heart, shown here. It’s approximately 1,000 mi (1,600 km) across. Comparatively, this is much larger than the size of the hearts of those who voted to demote it to a dwarf planet.
Shown here are the Krun Macula highlands. They come from the southeastern section of Pluto’s icy plains.
Shown here are some of Pluto’s “youthful” mountains.
Another lovely photo of Pluto’s heart, also called Sputnik Planum.
Shown here is a composite shot of Pluto with its moon Charon. it is the largest of Pluto’s five moons.
An image of Charon (okay, so this is technically a list of the top 9 Pluto photos). While Pluto was discovered in 1930, astronomers didn’t find Charon until 1978.
These are craters from Pluto’s Burney Basin, which is 155 mi (250 km) wide.