Uranus is the seventh planet from the Sun, the third largest in our solar system (51,488km wide), and the last planet visible with the naked eye. The planet has been visited just once back in 1986, with NASA’s Voyager 2 spacecraft coming within 81,500kms of its atmosphere.
Here are some more interesting facts about the planet Uranus:
Discovery: Although Uranus can be seen without a telescope, but being so far from the Earth means it moves very slowly in the night sky. It was therefore long believed to be a star. It wasn’t until 1779 that an amateur astronomer by the name of William Herschel spotted it in his homemade 6.2-inch reflector and correctly identified it as a planet.
Mythology: Uranus is named after the Greek god of the sky Ouranos, the father of Cronos (Saturn) and grandfather of Zeus (Jupiter). It was also a logical choice for the planet as the three bodies are now ordered according to their mythological lineage in the celestial heavens.
Composition: The planet Uranus is believed to have a rocky core and is composed of 83% hydrogen, 15% helium, and 2% methane. It is the methane gas above the cloud layers which gives the planet its blue-green color. Along with Neptune, Uranus is called an “ice-giant,” and with a minimum temperature of -224c, it is the coldest planet in our solar system.
Moons: Uranus is a “ringed” planet and has at least 27 moons, many of which are named after characters from the works of William Shakespeare and Alexander Pope. These include Miranda, Ariel, Umbriel, Titania and Oberon.
Orbit: The planet is tilted almost 98 degrees meaning its poles are near to where you would usually expect to find its equator. Consequently, despite Uranus revolving once every 17 hours and 14 minutes, one day on each of its poles lasts for 42 years. Uranus also takes 84 years to orbit around the Sun.
Viewing: Under optimal conditions, Uranus can be seen with the naked eye, but by using 10×50 binoculars, its faintly blue or green hue can be discerned. A 6-inch telescope with 300x or 400x magnification may enable you to see a pale cyan disk, equivalent in size to observing a golf ball from 12 feet away. However, it’s almost impossible to see details like cloud patterns, and some of the larger moons such as Titania and Oberon may require telescopes with at least an 8-inch aperture.