Tag Archives: ice giant


Neptune  is the eighth and most distant planet from the Sun.

The planet may have formed much closer to the Sun in early solar system history before migrating to its present position.


Neptune has 14 moons, the most interesting one being Titon, a frozen world,  probably the coldest in the Solar system.
Neptune is not visible to the naked eye,and therefore was unknown to the ancients. It was first observed by telescope in 1846, its position determined by using mathematical predictions.

Neptune is a gas giant, not a solid body. It spins on its axis very rapidly and takes 18 hours to make one rotation.

Neptune is also known as an ‘ice giant’, like the slightly larger planet Uranus. Although smaller than Uranus, Neptune has a greater mass.

The atmosphere of Neptune is made of hydrogen and helium with some methane. The methane absorbs red light, which makes the planet appear a beautiful blue. High, thin clouds drift in the upper atmosphere.

Neptune has a very active climate with large storms and high winds whirling around the upper atmosphere.Neptune is known for its ‘Great Dark Spot’, a massive storm which raged for about five years, recorded in 1989.

Neptune was flown by in 1989 by spacecraft Voyager 2.

The NASA/ESA Hubble Space Telescope has also studied this planet, as have a number of ground-based telescopes.

For more info on Neptune, visit:



Uranus is the seventh planet from the sun at a distance of about 2.9 billion km (1.8 billion miles) or 19.19 AU.

Uranus is an ice giant, with faint rings. The inner rings are narrow and dark and the outer rings are brightly coloured..

Uranus has an atmosphere which is mostly made up of hydrogen and helium with a small amount of methane which causes the planet to have a blue tint. Most of the planet’s mass is made up of a hot dense fluid of “icy” materials – water, methane and ammonia above a small rocky core.

Uranus is the only giant planet whose equator is nearly at right angles to its orbit. It is nearly the same size as the other ‘ice giant’, Neptune.

Uranus has 27 moons, many named after characters from the works of William Shakespeare and Alexander Pope such as Miranda, Titania, Oberon and Umbriel.

One day on Uranus takes about 17 hours (the time it takes for Uranus to rotate or spin once.)  A complete orbit around the sun takes about 84 Earth years.

Uranus is not visible to the naked eye but it became the first planet discovered with the use of a telescope. It was discovered by William Herschel.
Voyager 2  is the only spacecraft to have visited Uranus.