Quick Facts About Pluto
Day Length 153 hours (6.4 Earth days)
Year Length 248 Earth years
Diameter 1,151 kilometers (715 miles)
Planet Type Dwarf
Distance 39 AU (astronomical units)
What would it be like to stand on the surface of Pluto?
You would step out of your habitat in an EVA suit, that keeps you safe from below freezing temperatures and deadly Solar radiation. You’d look up and see the moon Charon, looming large in the sky, and possibly 4 other small moons. You’d see a rocky landscape, dotted with mountains and pocked with craters. You’d see volcanoes spewing ice and feel light enough to nearly float away into the abyss. If it were summer, mists would hug the surface of the planet; in winter, methane snow would blanket the rocky terrain. At noon the light would be no brighter than sunset on Earth. Even on this dwarf planet, you would feel small against the vast expanse of a world trapped in an endless twilight.
Pluto was discovered in 1930 by astronomer Clyde Tombough at the Lowell Observatory in Flagstaff, AZ, and named by an 11 year old girl from England, Venetia Burney, who submitted the name to Lowell (“History of Pluto”).
Pluto is a dwarf planet located at the outer edge of our solar system, and the largest object in the Kuiper Belt (Singer). At its small size its diameter is about half the size of the United States. Pluto’s mean temperature is -226° C (-375° F) and its gravity is 1/6th that of Earth’s (Bolles, “Pluto: Facts”).
If you were to stand on the surface of the planet at its brightest time, the light would be 1/900th that of Earth’s noon. In other words, astronomical twilight on Earth is about equal to noon on Pluto. The planet’s five moons are Charon, Nix, Styx, Kerberos, and Hydra. Charon is the largest of these moons at half the size of Pluto and it is tidal locked, so from the surface of Pluto the same side is always seen. Because of the synchronous rotation of the two, Charon never sets. Pluto’s other moons are all less than 160 km (100 mi) across and are not tidal locked.
Pluto’s core is thought to be rock and its mantle to be water-ice, with a subsurface ocean of water. Its terrain includes valleys, mountains, craters, and plains, all covered in methane and nitrogen ice. Enormous hummocky flanks (landslide avalanche areas) show evidence of cryovolcanoes, meaning that Pluto’s surface erupts with ice! Its tallest mountains are 3 km (1.9 mi) high and its craters can measure 260 km (162 mi) across. When the planet moves closer to the Sun its surface ices melt and turn into a mist; when it moves away from the Sun the mist freezes and falls to the surface as methane and nitrogen snow.
For a short video (5 min 42 sec) on this see:
“What Would It Be Like To Stand on Pluto?”
PLUTO: THE ROMAN GOD
Pluto and Hades are often thought of as interchangeable. They share many similarities and some differences. Pluto is the Roman god of the Underworld and Hades is his Greek equivalent (Wasson). Pluto’s parents were the Titans Saturn and Ops. His brother Jupiter granted Pluto dominion over the Underworld, which had many names: Tartarus, the Lower World, the Infernal Region, and Hades. His queen Proserpina (Persophone in Greek mythology) was kidnapped by him and forced to stay 3 months out of the year in the Underworld (although some accounts claim it is 6 months). Pluto was also known in Roman religion as Dis Pater (“rich father”) because he was thought to be quite wealthy, having found many precious metals and stones under the earth.
Pluto is characterized as a stern figure, unmoved by prayer or sacrifice, as dispassionate as death itself (van de Kerkhof). He is said to have an ebony throne that he sat upon and a gold chariot drawn by black horses. He carried the keys to Hades with him and wore a helmet that granted the wearer invisibility. A two-pronged scepter is also associated with Pluto.
Mercury, the messenger god, gathered souls to the Underworld. After crossing the River Styx with the ferryman Charon, souls were questioned by three judges (not Pluto) and weighed on the impartial scales of the blind goddess Themis. “If good outweighed the bad, the spirit would go to the Elysian Fields, or if bad outweighed good, the spirit must suffer the fires of Tartarus – a dark and gloomy place of endless sorrow and incessant torment” (Wasson). Pluto governed his realm with the help of the Furies, the Fates, and the Gorgons.
The dwarf planet Pluto has five moons, all named after other mythological figures:
Charon – the ferryman that brings departed souls across the River Styx
Styx – the river of darkness departed souls must cross in order to face judgment
Nix – the personification of night in Greek mythology (Miate)
Kerberos – Cerberus, Pluto’s three-headed dog, stood guard over the entrance of Hades with his poisonous fangs.
Hydra – a monster with nine venomous heads that would grow back should one of them be cut off (Mark)
Alistair McDowall might have chosen to set X on Pluto not just because it is the one of the furthest points in our solar system, but also because of the association with the god of the Underworld. Death hangs over the heads of the crew in different ways: the destruction of earth, the vastness of an unforgiving universe, and the disease or suicide that claims all original crew.
Bolles, Dana. “Pluto: Facts.” NASA, the Government of the United States of America, 10 November 2023, https://science.nasa.gov/dwarf-planets/pluto/facts/
“History of Pluto.” Lowell Observatory, https://lowell.edu/discover/history-of-pluto/
“New Horizons [Extended Version].” Youtube, uploaded by National Space Society, 30 June 2015, https://youtu.be/-Hbp8QYUQpc?feature=shared
Van den Kerkhof, Maup. “Pluto: The Roman God of the Underworld.” History Cooperative, 11 August 2022, https://historycooperative.org/pluto-god/
Wasson, Donald. “Pluto.” World History Encyclopedia, World History Publishing, 6 July 2023, https://www.worldhistory.org/Pluto/