Discovery of Ananke
The moons of Jupiter have been known about since 1610 when Galileo discovered the largest four known moons. The discovery of any further moons stalled when the technology needed was not available to identify any other moons with certainty. Seth Barnes Nicholas made the discovery of Ananke on September 28, 1951, using a 100-inch telescope at California’s Mount Wilson Observatory.
A former asteroid
The majority of astronomers agree the moon was once an asteroid traveling through space that was attracted to the gravitational field of Jupiter. The theory of the arrival of Ananke in orbit around Jupiter states a collision with another space object led to the asteroid breaking up and becoming a series of smaller moons.
The largest moon in the Ananke Group
Ananke is the largest moon in the group that bears its name having been measured as having a radius of 14 kilometers. The moon has a visible coloring of gray to light red which has aided scientists in deciding the moons surrounding it of similar colorings were once a single celestial body.
An irregular shape
Ananke moon is kown for its irregular shape that has backed up the claims of researchers that it was once an asteroid. Despite being the largest moon in the Ananke Group, the moon is not large enough to have morphed into a spherical shape and has maintained the irregular shape of an asteroid. Since the year 2000, the number of satellites and moons orbiting the planet of Jupiter in a similar orbit the have been identified has been growing as telescope technology continues to improve.
Ananke orbits millions of miles away from Jupiter
The orbit is not perfectly circular moving around Jupiter but brings the moon closer and further from the planet depending on the tidal movement of the planet. Throughout the year on Jupiter, the moon ranges from being just over 19 million miles from the surface to just under 23 million miles away.
The naming of Ananke
The moon of Ananke was discovered back in 1951 but did not receive an official name until 1975 when it was christened Ananke. The moon was first known as Jupiter XII and was often referred to as Adrastea. The name Ananke continues the tradition of giving the moons of Jupiter names that are based on characters from Greek mythology. For Ananke, the character is known in Greek mythology as the personification of inevitability.
The orbit of Ananke is characterized by its name
The retrograde orbit of this moon meant the name of the moon had to end in the letter e. Ananke is known for moving against the rotation of Jupiter in what is known as a retrograde orbit. The general classification of objects with a retrograde orbit is they must have a name that ends in the letter e.