# Hermippe, Moon of Jupiter

Hermippe is a Moon that orbits round the planet Jupiter. It is also know by other designations, JXXX, S/2001 J3. Its mass is estimated/calculated at being 89,920,105,985,832 kg. Its density has been calculated at being 2.6.

Hermippe was discovered on 9 December 2001 by Scott S. Sheppard, David C. Jewitt, and Jan T. Kleyna.

The orbital period, i.e. the period it takes to complete an orbit round Jupiter is 633.9 days. The figure is also known as the sidereel period. The figure comes from N.A.S.A..

The Equatorial Radius of the object is 2km. The Equatorial Radius is based on the assumption of the Albedo value. The value is the radius in km of the said object at the Equator.

The albedo of the object is 0.04. The Albedo is the amount of radiation that is reflected back into space by the object.

The Escape Velocity of the object is 9 km/h. The Escape Velocity is the speed an object needs to be travelling in order to break free from the objects gravity. The larger an object is, the more velocity (speed) is needed to break free from the object.The Semi-Major Axis of the orbit is 21130, which is the furthest point from the centre to the edge of an elliptical point.

The equatorial circumference of Hermippe is 12.6 km. The surface area of Hermippe is 50.27. The surface gravity of the said item is 0.002. The Mean orbit velocity, that is the speed at which it orbits is 8696.90 km/h. The is the average distance in km of the object is from its parent 21300000.00.

The orbital inclination, the angle at which Hermippe orbits in relation to the orbital plane is 150.7 degrees. The orbital eccentricity is 0.2123, it is the degree at which Hermippe orbits close to a circular (0) orbit as opposed to an elliptical (1) orbit.

## How Hermippe was Named

The moon Hermippe is named after the Greek daughter of Boeotus, who was a son of Poseidon, the Greek God of the Waters. Hermippe married Orchomenus who was a son of Zeus. She would later have a child with Poseidon. Orchomenus became the legal father of the child. Wiki

If you read the NASA story, it will say that Hermippe bore a son called Orchomenus rather than actually marrying him. However, NASA does go onto say that the name was chosen because it ended with an "e" to indicate that the moon has a retrograde orbit, an orbit in reverse to the others. This policy is in accordance with the the International Astronomical Union policy of naming moons.

## Ananke Moon Group

Ananke group of Jovian moons are all believed to have the same source, probably the result of a asteroid collision. The remnants were caught by the immense gravitational pull of Jupiter and remain in orbit ever since. The name derives it name from the largest in the group. All the members of the group orbit in a retrograde orbit hence why they all finish with the letter 'e' in their name.

## Hermippe Facts

 Type Moon Designations JXXX, S/2001 J3 Mass (kg) 89,920,105,985,832 Density (g/cm^3) 2.6 Orbital Direction Retrograde, opposite to the parents direction Date of Discovery 9 December 2001 Discoverer Scott S. Sheppard, David C. Jewitt, and Jan T. Kleyna Orbital Period (days) 633.9 Equatorial Radius (km) 2 Albedo 0.04 Escape Velocity (km/h) 9 Semi-Major Axis (10^3 km) 21130 Equatorial Circumference (km) 12.6 Surface Area (km^2) 50.27 Surface Gravity (m/s^2) 0.002 Mean Orbit Velocity (km/h) 8696.90 Average Orbit Distance (km) 21300000.00 Orbital Inclination (degrees) 150.7 Orbital Eccentricity 0.2123 Source(s) https://solarsystem.nasa.gov/moons/jupiter-moons/hermippe/in-depth/https://nssdc.gsfc.nasa.gov/planetary/factsheet/joviansatfact.html