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.
So everything we learn about the possible evolution of our own ice giants feeds in to our understanding of their far distant cousins and the evolution of potentially habitable worlds.
One exciting detail we studied that is very relevant to the question of extraterrestrial life is the fate of an atmosphere after a giant impact. Our high resolution simulations reveal that some of the atmosphere that survives the initial collision can still be removed by the subsequent violent bulging of the planet.
The lack of an atmosphere makes a planet a lot less likely to host life. Then again, perhaps the massive energy input and added material might help create useful chemicals for life as well.
Lots of questions remain about Uranus, and giant impacts in general. Even though our simulations are getting more detailed, we still have lots to learn. I would very much like to see that happen. The combination of observations, theoretical models and computer simulations will ultimately help us understand not only Uranus, but the myriad planets that fill our universe and how they came to be. Portsmouth Climate Festival — Portsmouth, Portsmouth.
Edition: Available editions United Kingdom. Another lucky incident occurred on 10 March , when the planet was scheduled to pass in front of a faint star. Because of uncertainties in the predicted time of the star's disappearance, one telescope was set into action about 45 minutes early.
Soon after the recording began, the starlight abruptly dimmed but then it almost immediately returned to normal, producing a brief dip in the recorded signal. At first, the dip was attributed to a wisp of cloud on Earth or to an unexpected change in the telescope's orientation. But the star blinked on and off several times before and after the planet covered it. Moreover, each dip on one side of Uranus was matched by another one on the other side, at the same distance from the planet.
During the next few years, observations of more than stellar occultations by Uranus revealed the details of nine narrow rings. From the brief duration of the dips of blocked starlight, astronomers concluded that all but one of the individual rings could be no wider than 10 kilometers.
The relatively long time between the dips indicated that the threadlike rings are separated by hundreds of kilometers of nearly empty space. These skeletal, web-like rings are unlike any seen before, all very narrow and widely spaced from each other.
When Voyager 2 arrived at Uranus in , nearly a decade after the discovery of its narrow rings, instruments on the spacecraft confirmed all the known rings, and added at least two. They found the?
The spacecraft also discovered at least 10 small moons that are located just outside the ring system. The particles in the main narrow rings of Uranus are both dark and large. They range between a softball and an automobile in size, or between 0. And they contain very few smaller particles in the millimeter to centimeter, or 0. Broad sheets of dust were nevertheless detected in the wide gaps between the rings.
The dust is lit up when the Sun shines through the rings, in the same way that grime on a car's windshield becomes visible when struck by the lights of an oncoming car. The irregular orientation and shapes of the Uranian rings are attributed to small moons that lie just outside them. The repeated gravitational tugs of two of them, Cordelia and Ophelia, pull the epsilon ring into its oval shape and restrain its edges. Nearby moons probably sharpen the edges of the other rings, keeping them from spreading out as the result of particle collisions, but many of the expected moons have not been found.
After the discovery of the rings of Uranus by watching a distant star pass behind the planet, astronomers hoped to repeat the achievement by observing stellar occultations by Neptune, but the results were inconclusive.
Sometimes the starlight would remain unchanged before and after the planet directly occulted the star. At other times the star would blink on and off, but always on just one side of the planet. Because the brief dimming of starlight was not symmetrical about the planet, and not all stellar occultations produced a blinking signal, the hypothetical rings became shortened, in the minds of the astronomers, to ring-arcs that only reached part way around the planet.
Chance might then dictate which astronomers would detect the obscuration. Voyager 2 clarified the problem. Neptune's ring-arcs turned out not to be isolated segments, but rather three thicker portions of one very thin ring.
The ring is narrow and continuous, stretching all the way round the planet just like any well-behaved ring. It was these high-density clumps that had been detected from Earth, blocking starlight and giving the impression of disconnected arcs.
It is now thought that all the planetary rings are younger than the age of the solar system, so they cannot be permanent features dating back to its origin. And the present rings are now viewed as a passing stage in an ongoing process of creation and loss.
The austere rings that now circle Uranus and Neptune may have had a violent and chaotic past, arising from catastrophic collisions of moons or when one larger satellite moved inward by tidal interaction with the planet until it was close enough to be ripped into pieces. Most of Neptune's moons are named after sea nymphs. What does Neptune look like? Neptune is dark, cold, and very windy. It's the last of the planets in our solar system.
The methane gives Neptune the same blue color as Uranus. Neptune has six rings, but they're very hard to see. Why is Neptune hotter than Uranus? The trouble with temperature In doing so we find that Neptune isn't actually hotter than Uranus in real terms — they're essentially at the same temperature. But since Neptune receives less solar illumination because it's farther from the sun, this shouldn't be the case.
Can we live on Neptune? Neptune, like the other gas giants in our solar system, doesn't have much of a solid surface to live on. But the planet's largest moon, Triton, could make an interesting place to set up a space colony. So far, only a single spacecraft has ever visited Triton. Where are fiber optic cables often used? What is internal and external criticism of historical sources?
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