# Elara, Moon of Jupiter

Elara is a Moon that orbits round the planet Jupiter. Its mass is estimated/calculated at being 869,227,691,196,372,000 kg. Its density has been calculated at being 2.6. Its volume is 333038.

It was discovered in the year 1905 by Charles Dillon Perrine.

The orbital period, i.e. the period it takes to complete an orbit round Jupiter is 259.6528 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 43km. 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 187 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 11740, which is the furthest point from the centre to the edge of an elliptical point.

The equatorial circumference of Elara is 43.0 km. The surface area of Elara is 23,235.22. The surface gravity of the said item is 0.031. The Mean orbit velocity, that is the speed at which it orbits is 11697.50 km/h. The is the average distance in km of the object is from its parent 11741000.00.

The orbital inclination, the angle at which Elara orbits in relation to the orbital plane is 24.77 degrees. The orbital eccentricity is 0.2174, it is the degree at which Elara orbits close to a circular (0) orbit as opposed to an elliptical (1) orbit.

## Legend of Elara

the moon, the eighth largest Jovian moon is named after one of Zeus, the King of the Gods' lovers. Zeus is the Greek equivalent to the Roman god Jupiter. Elara became pregnant with Zeus' child and was hidden by Zeus in the underworld from Hera, Zeus's wife.

The name was chosen because it ended in the letter "a" which according to the International Astronomical Unions guidelines for Jovian moons, orbits in the same direction as Jupiter. Those moons that are retrograde end with the letter "e" such as Autonoe. NASA

## Himalia Moon Group

The moon is a member of the Himalia group of Jovian Moons. All four Himalia moons in the group orbit in a prograde direction, this means they orbit in the same direction as Jupiter. They are all believed to be from the same source, possibly the remnants of an asteroid that got broken up in a collision. Himalia is the largest member of the group therefore it is the one that the group is named after. It takes just over two thirds the time the moon takes to orbit the Earth as Himalia takes to orbit Jupiter. NASA

## Elara Facts

 Type Moon Mass (kg) 869,227,691,196,372,000 Density (g/cm^3) 2.6 Volume (km^3) 333038 Orbital Direction Prograde, same as the parents direction Year of Discovery 1905 Discoverer Charles Dillon Perrine Orbital Period (days) 259.6528 Equatorial Radius (km) 43 Albedo 0.04 Escape Velocity (km/h) 187 Semi-Major Axis (10^3 km) 11740 Equatorial Circumference (km) 43.0 Surface Area (km^2) 23,235.22 Surface Gravity (m/s^2) 0.031 Mean Orbit Velocity (km/h) 11697.50 Average Orbit Distance (km) 11741000.00 Orbital Inclination (degrees) 24.77 Orbital Eccentricity 0.2174 Source(s) https://solarsystem.nasa.gov/moons/jupiter-moons/elara/in-depth/https://nssdc.gsfc.nasa.gov/planetary/factsheet/joviansatfact.html