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.
This causes the star to appear fainter. Uranus' environment is not conducive to life as we know it. The temperatures, pressures, and materials that characterize this planet are most likely too extreme and volatile for organisms to adapt to. 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.
All four outer planets — Jupiter, Saturn, Uranus, and Neptune — have rings. But the rings of Uranus have had scientists scratching their heads for decades.
They have known about 11 such rings since the s, and discovered two more in , taking the number to The rings of Uranus contain pieces larger than golf balls, and no dust, unlike the rings of other outer planets. There is debris between the rings, and the widths of the rings are around 20 to kilometres, about times narrower than the rings of Saturn. They are also much darker than the rings of the outer planets, making them difficult to study with telescopes.
Bode argued that as Saturn was the father of Jupiter, the new planet should be named for the father of Saturn. Uranus is blue-green in color, as a result of the methane in its mostly hydrogen-helium atmosphere.
Unlike the other planets of the solar system, Uranus is tilted so far that it essentially orbits the sun on its side, with the axis of its spin nearly pointing at the star. This unusual orientation might be due to a collision with a planet-size body, or several small bodies, soon after it was formed. A study suggested the colliding world could have been twice the size of Earth.
This unusual tilt gives rise to extreme seasons that last for about 20 years. This means that for nearly a quarter of the Uranian year, which is equal to 84 Earth-years, the sun shines directly over each pole, leaving the other half of the planet to experience a long, dark and frigid winter. Uranus has the coldest atmosphere of any of the planets in the solar system, even though it is not the most distant from the sun.
That's because Uranus has little to no internal heat to supplement the heat from the sun. The magnetic poles of most planets are typically more or less lined up with the axis along which it rotates, but Uranus' magnetic field is tilted, with its magnetic axis tipped nearly 60 degrees away from the planet's axis of rotation. This leads to a strangely lopsided magnetic field for Uranus, with the strength of the field at the northern hemisphere's surface being up to more than 10 times that of the strength at the southern hemisphere's surface.
A study suggested the lopsided nature of Uranus' magnetic field may also lead it to flicker on and off during every rotation about every Uranus' atmospheric composition by volume is
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