Basically, when a planet's orbital precession, or shifts in its orbit around the sun, matches up with its rotational precession, or how much the planet wobbles when rotating, it begins to tilt. They propose that Uranus once had a larger, more robust ring system, which would have caused it to wobble even more. In fact, the planet still has rings today, but they are incredibly thin compared to Saturn's luminous rings. As the planet accreted more and more material from this disk, it grew and grew and, eventually, tipped over.
But there's a catch. When Rogoszinski and Hamilton created a model using this theory, it revealed a Uranus that was only tilted 70 degrees. What could have given it the extra push to 98 degrees? For now, it's just a theory. There's still a lot we don't know about Uranus. Only one way to solve that For starters, Uranus spins on an extreme tilt, resulting in some crazy seasons around the poles.
OK, let's not kid ourselves. You're never too old to enjoy a good Uranus joke. English-speakers tend to pronounce "Uranus" in one of two ways. Some folks say, "urine us," but most prefer the alternative which sounds like "your anus. In a bid to minimize rectum comments, Planetary Society blogger Emily Lakdawalla has trained students to point and shout " You're a nuss! Puns aside, Uranus represents a break with nomenclatural tradition.
However, Uranus — uniquely — was named after a Greek god. In the religion of ancient Greece, Uranus was revered as the primordial god of the sky. He had a son named Cronos and a more famous grandson known as Zeus. These figures were later conflated with two Roman deities: Saturn and Jupiter. Though the planet Uranus was discovered by astronomer William Herschel March 13, , he didn't give it the name we use today.
By nature that name was politically charged. To avoid alienating non-British stargazers, German astronomer Johann Elert Bode suggested calling the planet "Uranus" in Eventually, his alternative moniker won out.
Bode may have been German, but the planet he named looks like it's trapped in a Dutch angle. Planets rotate around an axis, the line connecting their northern and southern poles.
And speaking of spin cycles, you probably know that all the planets in this solar system are simultaneously orbiting the sun. Now Earth has an axial tilt of This means there's a Without the tilt, our home world wouldn't have seasons or possibly life.
Uranus is skewed, too — but to a much greater extent. In relation to its orbital plane, the ice giant's axis has been tilted at a jaw-dropping Next to Saturn and Neptune, Uranus looks like its lying on its side. What's up with the weird orientation?
A computer simulation published in suggests Uranus was hit by a huge proto-planet around 4 billion years ago. Supposedly, this collision gave the ice giant its exaggerated tilt. Then again, perhaps there were multiple impacts. A long-gone circumplanetary disk might've also played a role here.
The tilt subjects both poles to long, dark winters and long, bright summers. One year on Uranus lasts for roughly 84 Earth years. Each pole is aimed almost directly at the sun — for about 21 straight Earth years — during its summer season. Meanwhile, the other pole faces the opposite direction, enduring a sunlight-free winter. Despite the extreme tilt, Uranus is warmer at the equator than it is at either pole.
Nobody knows why, and this isn't the planet's only mystery. Jupiter, Saturn and Neptune all radiate more than twice as much heat as they receive from the sun. Yet Uranus's heat output is significantly lower. The disparity has long baffled planetary scientists. Disks are relatively short-lived and only hang around for about 1 million years before the material either falls into the planet or forms a moon.
That means Uranus only has one million years to turn on its side before the disk dissipates and the tilt is permanent. In order to determine if different types of disks are capable of tilting Uranus or Neptune, the authors built computer models that capture the physical interactions of the disk and the planet. Three of the most relevant models are summarized here. Model 1 is the simplest. It has a disk with constant mass for 1 million years before dissipating instantly.
The authors find that a constant disk could cause Uranus to tilt, but it could just as easily undo the tilt, making it too unpredictable. Figure 3. The results of the second model, in which the disk slowly dissipates over one million years bottom. Model 3 is the same as model 2, but Uranus grows in mass as material from the disk falls onto it, shown in Figure 4. Figure 4. The result of the final model, which contains a slowly dissipating disk second from bottom and material falling onto Uranus.
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