Uranus: The Sideways Planet

The Bluish-grey giant is fallen over its axis and is rolling on the plane of the solar system. There are some fascinating facts about this cold world that makes it a unique place in our solar system. 

A Bit of History

The observation was reported by William Herchel on 26 April 1781 as a comet but was accepted globally to be a planet by 1783. It is the only planet in our solar system that is named after the Greek God of the sky(Ouronus). Every Other planet is named after a Roman God. 

Voyager 2 is the only spacecraft up until today to investigate the planet Uranus up close. On its closest approach, Voyager 2 reached 81,000 km above cloud tops of Uranus while studying 5 major moons and also discovered 10 new natural satellites around the planet. It also examined 9 known rings of the planet and discovered 2 new rings. 

Place in the solar system

The average orbit distance of Uranus is 20 times the distance of Earth from the Sun. At this Distance, Light from the Sun takes 2 hours and 40 minutes to reach the planet. The difference between the closest point and farthest point of Uranus from the Sun is 1.8 AU, Greater than any other planet in our planetary system. 

Uranus completes one revolution around the Sun every 84 years and rotates around its own axis in about 17 hours, 14 minutes. The rotational axis of Uranus is tilted by 97 degrees such that, while other planets spin inside the plane of the solar system, Uranus rolls on this plane. 

Diameter	50,724 km
Mass	8.68 x 1025 kg
Mean Density	1.27 g/cm3
Surface Gravity	8.69 m/s2
Equatorial Radius	25,560 km
Polar Radius	24,970 km
Orbital Eccentricity	0.0463
Escape Velocity	76,680 km/h

Uranian Natural Satellites

The Moons of Uranus are named after figures of English literature. There are a total of 27 known natural satellites orbiting Uranus. And these moons are differentiated into 3 categories:  

Inner moons (13)	Major Moons (5)	Irregular Moons (9)
Cordelia Ophelia Bianca Cressida Desdemona Juliet Portia Rosalind Mab Belina Perdita Puck Cupid	Miranda Ariel Umbriel Titania Oberon	Francisco Caliban Stephano Trinculo Sycorax Margaret Prospero Setebas Ferdinand

Puck is the largest of the inner moons at around 160 km in diameter. On the other hand, Titania is the largest of Major moons and the 8th largest in our solar system with 1578 km in diameter. The axial tilt of these major moons is the same as the host planet. The irregular moons are much further out in the orbit of Uranus and are highly considered to be captured moons with the biggest: Sycorax with around 200 km diameter. 

Key facts

• The pressure at the base of the mantel of Uranus is enough to compress carbon atoms into diamonds. It is believed that there are liquid oceans diamonds at the bottom of the mantel. 

• The uranian natural Satellite system is least massive if compared to other Gas Giants in our solar system. The combined mass of 5 major moons of Uranus is less than the mass of Triton: The largest moon of Neptune.