Discovery
Hyperion is one of Saturn’s moons and was discovered in 1848 by William Lassell. That same year William Cranch Bond, with his son George Phillips Bond, independently discovered the moon. All three men are jointly credited with the discovery.
How Hyperion Got its Name
Astronomer John Herschel suggested that Saturn’s moons be associated with the brothers and sisters of the mythical Kronus (Greek mythology equivalent of Roman god Saturn). Hyperion was the mythical Titan (or Greek god), who was the son of Uranus and Gaia, brother of Kronus and the husband of Thea. The children of Hyperion and Thea include Helios (the sun), Eos (the dawn) and Selene (the Moon).
Hyperion mean “he who watches over”.
Overview
Hyperion is the largest of Saturn’s irregular, nonspherical moons, with a mean radius of 3.9 miles (135 kilometers). However, it does look like a potato so its shape can be described in terms of its diameter along its three axes: 255 x 163 x 137 miles (410 x 260 x 220 kilometers, respectively). Due to this odd shape, it is possible that Hyperion is probably a remnant of a larger moon that was destroyed by a major impact.
The density of this moon is slightly more than half that of water, which could be due to water ice with gaps (porosity) of more than 40 percent. It is also possible that other lighter materials such as frozen methane or carbon dioxide, make up part of Hyperion. According to NASA, “This is consistent with the concept of Hyperion accreting from a number of smaller ice and rock bodies, but not having enough gravity to compact them. Thus, Hyperion might be similar to a large rubble pile.”
A 3D model of Hyperion, a moon of Saturn. Credit: NASA Visualization Technology Applications and Development (VTAD)
Hyperion rotates in rather a chaotic manner, ” tumbling unpredictably through space as it orbits Saturn“, roughly every 13 days during its 21-day orbit. The orbit is at an distance of 933,000 miles (1,500,000 kilometers) from Saturn in an eccentric orbit. As per NASA: “This contributes to variations in the spin or rotation of Hyperion. A stronger effect on Hyperion’s rotation is that it is in resonance with Saturn’s largest moon, Titan, which orbits at 759,200 miles (1,221,850 kilometers). Thus, the two objects speed up and slow down as they pass each other in a complex set of variations. Because Hyperion is much smaller than Titan, its rotation and orbit are affected vastly more than the larger moon, and Titan apparently keeps the Hyperion orbit eccentric rather than growing more circular over time.”
Due to its great distance from Saturn and its constant resonance with the other moon Titan, has prevented Hyperion from becoming tidally locked with its planet.
According to NASA:
“The most noticeable close-up feature of Hyperion is its deeply cratered surface. Hyperion and its sister outer moons, Phoebe and Iapetus, all show extensive cratering because they are Saturn’s most distant moons and have experienced very little tidal warming that might blur or erase earlier features. However, the Hyperion craters are particularly deep and do not have significant rays of ejecta (although there appears to have been slumping or landslides inside many of the bigger craters). The result is a curiously punched-in look, somewhat like the surface of a sponge or a wasp nest. Planetary geologists have theorized that Hyperion’s high-porosity and low density would crater more by compression than excavation.
Many of the crater walls on Hyperion are bright, which suggests an abundance of water ice. The crater floors are mostly the areas of the lowest albedo (a measure of how reflective the surface is) and greatest red coloration. This may be because the average temperature of roughly -300 degrees Fahrenheit (-180 degrees Celsius) might be close enough to a temperature that would cause volatiles to sublimate, leaving the darker materials accumulated on the crater floors. This scenario fits with some of the newer crater floors being bright water ice.”
Saima Baig
I am a Chartered Environmentalist from the Royal Society for the Environment, UK and co-owner of DoLocal Digital Marketing Agency Ltd, with a Master of Environmental Management from Yale University, an MBA in Finance, and a Bachelor of Science in Physics and Mathematics. I am passionate about science, history and environment and love to create content on these topics.
