The ice giant has the most significant axial tilt among the Solar System planets; in comparison, its neighbor, Neptune has an axial tilt of A consequence of this is that near the solstices, one pole of Uranus continuously faces the Sun, leading to a very unusual day-night cycle across the planet.
At the poles, one will experience 42 Earth years of day followed by 42 years of night. Scientists suspect that about 3 to 4 billion years ago, one or multiple impacts tipped the ice giant on its side. Uranus orbits the Sun every 84 Earth years. In , the ice giant will complete its third orbit around the Sun since the moment of its discovery in One Uranian sidereal day is 17 hours 14 minutes 24 seconds and, due to its great distance from the Sun, a single solar day there is about the same.
This means that one Uranian year lasts for 42, Uranian solar days. Uranus is the seventh planet from the Sun. Only Neptune is further without taking into account the dwarf planet Pluto. The distance from Uranus to the Sun is about 20 AU or 2 billion km 2 billion miles. This is just an average number, though; following an elliptical orbit, Uranus can reach the minimum and maximum distances from the Sun.
They are called aphelion and perihelion, respectively. The distance between aphelion and perihelion is more extensive than that of any other planet — about 1. The planets of the Solar System are in constant motion, so the distance between them is changing daily. At the closest, the Earth is 2. At the farthest, the planets are separated by 3.
The spacecraft was launched in August and made its closest approach to the ice giant on January 24, Voyager 2 is the only space probe that has studied Uranus. Several exploration missions to Uranus had been proposed, but by , none of them got the final approval. For now, we receive information about the ice giant from observations via the Hubble Space Telescope and several powerful ground-based telescopes.
Along with its neighbor Neptune, Uranus is one of two ice giants of the Solar System. In fact, Uranus is a ball of gas and ice.
Uranus formed about 4. The ices that formed Uranus and the other Jovian planets were abundant enough and allowed the giant planets to grow massive. Uranus most likely formed closer to the Sun and moved to the outer Solar System about 4 billion years ago, where it took its place as the seventh planet from the Sun.
Uranus consists of three layers: a small iron-nickel core in the center, an icy mantle in the middle, and outer gaseous hydrogen, helium, and methane atmosphere.
Its gaseous atmosphere transitions into the internal liquid layers. Uranus is also is freezingly cold! Like the other giant planets, Uranus has a moon system. Uranus has 27 known moons. They stand out as the least massive moon system among those of the giant planets. For example, the combined mass of the five major satellites Miranda, Ariel, Umbriel, Titania, and Oberon would be still less than half that of Triton, the largest moon of Neptune, alone.
The five big round moons are quite similar in terms of composition, being about half rock and half ice. They all have impact craters and tectonic features like canyons and cliffs.
On Oberon, the highest mountain is similar in height to Mauna Kea on Earth. At Umbriel, there is a crater called Wunda crater which has a strange bright ring of material in it.
It may be carbon dioxide ice. The ring is about five kilometers in width. At Ariel, there are low-lying smooth plains that probably formed from cryovolcanism, where a water and ammonia solution erupted on the surface less than million years ago. This is a transcript from the video series A Field Guide to the Planets. Watch it now, Wondrium.
Its patchwork surface seems to have been stitched together from different parts. The topography on Miranda is highly varied. In addition to towering cliffs, Miranda also features grooved oval and chevron-shaped features called coronae. Perhaps long ago, Miranda was broken apart by a catastrophic impact, but then the pieces pulled back together gravitationally, but in a mixed up order.
The grooved coronae would have then formed as the heavier, rocky parts of the moon descended to the interior and the more buoyant, ice-rich parts rose to the surface.
Tidal forces from Uranus would have repeatedly flexed and squeezed Miranda, causing enough heat for the icy material of the moon to move easily. Rising intrusions of warm ice called diapirs would have pushed up on the surface of Miranda, causing the grooved terrain that is seen.
It is possible that a similar mechanism is responsible for the coronae on Venus, except that Venus has rising diapirs of warm rock, not ice, that create the oval, crown- like surface features.
Learn more about Saturn and the rings. In addition to moons, Uranus also has rings—13 of them. This sounds like a lot, but the rings are very thin and dark, with some wide separations. These rings were accidentally discovered in This is called an occultation study. In this style of study, one waits until the timing is just right, so that when looking from Earth, the planet to be studied passes in front of a faraway, fixed star.
It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode. Instead, the scientific community accepted Bode's suggestion to name it Uranus, the Greek god of the sky, as suggested by Bode. Uranus is about four times wider than Earth. If Earth were a large apple, Uranus would be the size of a basketball.
Uranus orbits our Sun, a star, and is the seventh planet from the Sun at a distance of about 1. Uranus takes about 17 hours to rotate once a Uranian day , and about 84 Earth years to complete an orbit of the Sun a Uranian year. Uranus is an ice giant. Most of its mass is a hot, dense fluid of "icy" materials — water, methane and ammonia — above a small rocky core.
Uranus has an atmosphere made mostly of molecular hydrogen and atomic helium, with a small amount of methane. 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.
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