With a radius of 15, If Earth was the size of a nickel, Uranus would be about as big as a softball. From an average distance of 1. One astronomical unit abbreviated as AU , is the distance from the Sun to Earth. From this distance, it takes sunlight 2 hours and 40 minutes to travel from the Sun to Uranus.
One day on Uranus takes about 17 hours the time it takes for Uranus to rotate or spin once. And Uranus makes a complete orbit around the Sun a year in Uranian time in about 84 Earth years 30, Earth days.
Uranus is the only planet whose equator is nearly at a right angle to its orbit, with a tilt of This unique tilt causes the most extreme seasons in the solar system. For nearly a quarter of each Uranian year, the Sun shines directly over each pole, plunging the other half of the planet into a year-long, dark winter.
Uranus is also one of just two planets that rotate in the opposite direction than most of the planets Venus is the other one , from east to west. Uranus has 27 known moons. While most of the satellites orbiting other planets take their names from Greek or Roman mythology, Uranus' moons are unique in being named for characters from the works of William Shakespeare and Alexander Pope.
All of Uranus' inner moons appear to be roughly half water ice and half rock. The composition of the outer moons remains unknown, but they are likely captured asteroids. Uranus has two sets of rings. The inner system of nine rings consists mostly of narrow, dark grey rings. There are two outer rings: the innermost one is reddish like dusty rings elsewhere in the solar system, and the outer ring is blue like Saturn's E ring.
Some of the larger rings are surrounded by belts of fine dust. Uranus took shape when the rest of the solar system formed about 4. Uranus has 27 known moons.
Oberon and Titania are the largest Uranian moons, and were the first to be discovered, by Herschel in William Lassell, who was also the first to see a moon orbiting Neptune, discovered Uranus' next two moons, Ariel and Umbriel. In , Voyager 2 visited the Uranian system and discovered an additional 10 moons, all just 16 to 96 miles 26 to km in diameter:Juliet, Puck, Cordelia, Ophelia, Bianca, Desdemona, Portia, Rosalind, Cressida and Belinda. Each of those moons are roughly half water ice and half rock.
Since then, astronomers using Hubble and ground-based observatories have raised the total to 27 known moons, and spotting these was tricky — they are as little as 8 to 10 miles 12 to 16 km across, blacker than asphalt and nearly 3 billion miles 4. Between Cordelia, Ophelia and Miranda is a swarm of eight small satellites crowded together so tightly that astronomers don't yet understand how the little moons have managed to avoid crashing into each other.
Anomalies in Uranus' rings lead scientists to suspect there might still be more moons. In addition to moons, Uranus may have a collection of Trojan asteroids — objects that share the same orbit as the planet — in a special region known as a Lagrange point.
The first was discovered in , despite claims that the planet's Lagrange point would be too unstable to host such bodies. Although there isn't a spacecraft on its way to Uranus at the moment, astronomers regularly check in with the planet using the Hubble and Keck telescopes.
And in , NASA suggested a number of potential future missions to Uranus in support of the forthcoming Planetary Science Decadal Survey, including flybys, orbiters and even a spacecraft to dive into Uranus' atmosphere. Scientists are still discussing the idea. Uranus has 27 known moons, and they are named after characters from the works of William Shakespeare and Alexander Pope. Uranus has 13 known rings. The inner rings are narrow and dark and the outer rings are brightly colored.
Voyager 2 is the only spacecraft to fly by Uranus. No spacecraft has orbited this distant planet to study it at length and up close. Like Venus, Uranus rotates east to west. But Uranus is unique in that it rotates on its side. Uranus is the "butt" of more than a few jokes and witty and not so witty puns, but it's also a frequent destination in various fictional stories, such as the video game Mass Effect and TV shows like "Doctor Who.
Uranus is made of water, methane, and ammonia fluids above a small rocky center. Its atmosphere is made of hydrogen and helium like Jupiter and Saturn, but it also has methane. The methane makes Uranus blue. Uranus also has faint rings. The inner rings are narrow and dark. The latter two may be warmed enough by gravitational tugs from Uranus and other moons to create liquid water beneath their surfaces.
Investigating this possibility would help us learn about the possibilities for life far outside the habitable zone , the not-too-hot, not-too-cold region around stars where liquid can exist on planetary surfaces.
Like Neptune, only one spacecraft has ever visited Uranus. Missions to the outer planets require long travel times, which typically means higher costs.
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