A World Criss-Crossed With Canyons And Ridges!

One of the large spherical moons of Uranus, Ariel was named after a sky spirit in Alexander Pope's The Rape of the Lock and a spirit from Shakespeare's The Tempest. It’s the second closest of the 5 large moons, but the most reflective, possibly on account of its relatively young dynamic and varied surfaces!


Fast Summary Facts All About Icy Ariel!

  • Discovered: October 24th, 1851 by William Lassell
  • Name: Named after the character in Shakespeare's The Tempest
  • Size: Diameter of 1,155 km (718 miles)
  • Moon Rank: 14th Largest in the solar system
  • Orbit: Prograde and Circular
  • Orbit Radius: 190,020 km from Uranus
  • Orbital Period: 2 days, 12 hours
  • Orbital Speed: 5.51 km/sec
  • Orbital Inclination: 0.26° (to Uranus’ equator)
  • Rotation: Synchronous (rotates once every revolution so the same side always faces Uranus – known as tidally locked)
  • Density: 1.60 g/cm3
  • Surface Temperature: A chilly -213 °C (60K)
  • Surface: Equally water-ice and rock (rocky core)

More Cool Interesting Facts About The Distant Moon Ariel!

  • As with the rings and other large moons of Uranus, Ariel orbits close to its planet's equatorial plane. This means the moon share Uranus' extreme seasonal cycle on account of each pole experiencing permanent night or daylight for half a Uranian year – which is 42 Earth years!
  • Ariel is among the smallest of the Solar System’s known spherical moons, with only Miranda being closer to the planet of the round Uranian moons.
  • Scientists have calculated that its mass is composed equally of water ice and a rocky core, with a mass around the same as all of Earth's water in the oceans, lakes & rivers.
  • Every 42 years, around equinoxes, it’s possible to capture a rare transit of Ariel as the moon passes in front of Uranus and casts a shadow on the planet.
  • Ariel has a possibly has some of the youngest features of Uranian moons, with a complex surface covered in craters, plains crisscrossed by scarps, canyons, and ridged terrain.
  • The images from the 1986 Voyager 2 spacecraft (the only probe to have visited the Uranus system and photographed only 35% of Ariel’s surface) shows a canyon called Kachina Chasma that is over 620 km in length and is likely longer as it extended to an area Voyager couldn’t see.
  • It is thought that the plains formed through volcanic processes; possibly erupting liquid of supercooled water/ammonia solution maybe even solid ice volcanism! How cool! Several of these regions appear to be less than 100 million years old, indicating that Ariel may still be geologically active.
  • It is believed that Ariel formed billions of years ago, from the accretion disc that surrounded the newly formed Uranus; perhaps even from debris from the colossal impact that pushed Uranus onto its side!
  • Unfortunately, there are no plans for any future probes to visit Uranus (and its moons), but one day its hoped that a Uranus orbiter reaches this distant outpost!
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