Uranus

Uranus is a gas giant, positioned after Saturn in the orbit around the Sun. It is the only plants whose equator is almost right angled to its orbit. That is the poles of the plant are almost in parallel with its orbit. Uranus orbits the sun at a distance of about  1.8 billion miles (2.9 billion km) or 19.19 AU.

One day(the  time it takes for a planet to spin once) on Uranus takes about 17 hours. Uranus year is equivalent to 84 Earth years. It makes a complete orbit around the sun in about 84 years.

Uranus is a hot dense fluid of “icy” materials – water (H2O), methane (CH4). and ammonia (NH3) – above a small rocky core. Uranus has an atmosphere which is mostly made up of hydrogen (H2) and helium (He), with a small amount of methane (CH4).

NASA/Space Telescope Science Institute

NASA/Space Telescope Science Institute

 Moons

Uranus has 27 moons in total. They are named after characters from the works of William Shakespeare and  Alexander Pope.

The first two moons that were discovered by William Herschel in 1787. They are Oberon and Titania, and they  are the largest moons. William Lassell, who discovered Neptune moon also discovered the Uranus next two, Ariel and Umbriel. Nearly  after a century  Gerard Kuiper found Miranda in 1948. Rest were discovered by NASA Voyager 2.

HST false-colorpicture

HST false-color picture

Uranus has faint rings. The inner rings are narrow and dark and the outer rings are brightly colored.

Like Venus, Uranus has a retrograde rotation (east to west). Unlike any of the other planets, Uranus rotates on its side, which means it spins horizontally.

History in Uranus Discovery

  • 1781: Astronomer William Herschel discovers Uranus.
  • 1787-1851: Four Uranian moons are discovered and named Titania, Oberon, Ariel, and Umbriel.
  • 1948: Another moon, Miranda, is discovered.
  • 1977: Scientists discover nine faint rings of Uranus while observing a distant star pass behind the planet.
  • 1986: Voyager 2 discovers 10 moons and two additional rings during its historic flyby.
  • 1997-2005: Astronomers discover more tiny moons.
  • 2003-2005: The Hubble Space Telescope images two delicate rings far from the planet and two new moons.
  • 2007: Uranus reaches equinox.