10 Interesting Facts About Uranus

Planet Uranus. Elements of this image furnished by NASA.
Planet Uranus. Elements of this image furnished by NASA.

Uranus was the first planet to be discovered with the help of a telescope. The discovery was made in 1781 by an astronomer called William Herschel, who at the time was charting stars in the sky. He initially concluded that he had stumbled upon a comet. Further analysis of the celestial body, however, led to the calculation of the object’s orbit, a result that was contrary to the expected elliptical path of a comet. He further observed that the body was circular. Several astronomers also confirmed his observations and led him to conclude that he had indeed discovered a new planet.

Initially Named After A King

After the discovery, Herschel suggested Georgium Sidus (meaning Georgian Planet in Latin) for its name to honor King George III. The name was, however, not widely accepted and was finally dropped in favor of Uranus. The new name followed a tradition of naming new planets after Roman mythological deities.

Lowest Recorded Temperature Of Any Solar System Planet

Uranus is the seventh most distant planet in the Solar System. The planet orbits about 1.79 billion miles away from the sun. While Neptune, which is farther away, has the coldest average temperature, Uranus goes into the books for the lowest recorded temperatures. The unexpected observation is due to the unique properties of its core, thought to have cooled down at some point.

Uranus Appears Blue

Uranus has a blue appearance that makes the study of atmospheric patterns much more difficult compared to Saturn and Jupiter. The atmosphere is made up of 83% hydrogen, 15% helium, and 2% methane. The planet’s blue appearance is due to the absorption of red light by methane, which then scatters away blue light.

Uranus Has The Greatest Axial Tilt

The axial tilt of Uranus is by far the unique among all planets. While other planets rotate on their axis with a tilt relative to the sun, the axial tilt of Uranus is far more pronounced. For comparison, the axial tilt of Mars is 24 degrees, and Earth’s axial tilt is about 23.5 degrees while that of Uranus is 98 degrees.

42 Years Of Sunlight On Uranus

The axial tilt of Uranus means that one of its poles is always facing the sun at any given point. The resulting phenomenon is days in either pole that lasts 84 Earth years. If one stood on either pole of the planet, one would probably and experience 42 years of sunlight and 42 years under cover of darkness.

Uranus Has 27 Moons

Uranus has a total of 27 moons, each of which is named after characters in the works of Alexander Pope, William Shakespeare. The moons of Uranus are, however, considered small and somewhat irregular. If the mass of all the moons around the planet were added up, it probably would not match the mass of Neptune’s largest moon, Triton. The moons around Uranus are all thought to have been formed from the accretion disk around the planet. This contrasts Triton, which was captured by Neptune’s gravitational pull. Some of the planet’s largest moons include Miranda, Umbriel, Titania, and Oberon. Miranda is made of ice that may consist of carbon dioxide and ammonia. The rocky substance on the moon is thought to be made of carbonaceous matter. Scientists also believe that oceans of liquid water may exist at the mantle-core boundary of both Oberon and Titania.

Uranus Has Rings

Like all ice and gas giants in the solar system, Uranus also has rings. The rings are made up of dark particles that vary significantly in size. However, the rings are not as prominent as those around Saturn. Scientists believe that the rings are relatively young and might not have been formed during the formation of the planet. The origin of the particles forming the rings might have been from one or a number of its moons shattered due to high-speed impact.

Uranus Is Visible To The Naked Eye

Despite being the seventh most distant planet from the sun and over a billion miles away from the Earth, Uranus can still be viewed with unaided eyes. The planet has a magnitude of 5.3, which falls within the scale of brightness perceivable by the human eye. To view the planet, one must, however, ensure that the darkness of the night sky is not subject to light pollution. Most importantly, one must also know where to look since the night sky might be a bit overwhelming for an amateur. The planet has, therefore, been spotted multiple times by pre-modern and ancient astronomers who generally mistook it for a distant star due to its relatively low luminosity.

One Of Lowest Density In The Solar System

The density of Uranus is one of the lowest in the Solar System with a mean density of 0.0459 lbs/in3. The planet’s density only comes second after Saturn, which has a density of 0.0248lbs/in3.

Spacecraft Visit To Uranus Happened Only Once

Uranus has only received one visit by a spacecraft. The flyby was conducted by NASA’s Voyager 2 at a distance of 50,331 miles from the planet's cloud tops in January 1986. The vessel collected valuable information about the planet and also took numerous photographs of the planet. In 2009, the possibility of extending the space mission of the Cassini spacecraft (at the time studying Saturn) to Uranus was discussed but was never actualized.

Missions To Uranus Take Decades To Plan

Traveling to other planets has always been quite a challenge. Both the planet you want to visit and the starting point are in constant motion, which means that a lot of effort has to go into the planning of such trips. Waiting for the ideal circumstances to travel to planets such as Mars or Venus may take months or years. Traveling to planets such as Uranus, on the other hand, could mean that one has to wait a few decades for the ideal conditions. Currently, NASA is evaluating the possibility of future missions to Uranus and Neptune to help in the upcoming Planetary Decadal Survey. The results of the survey will help NASA determine its planetary science priorities going into the future.


More in Environment