Uranus’ colossal 98-degree tilt could be due to a MOON migrating away from the planet, pulling it sideways, astronomers say
- Oddly enough, Uranus has an axis of rotation so crooked that it might as well lie flat
- The seventh planet from the Sun has a whopping 98 degree inclination from the orbital plane
- Astronomers say this could be due to the moon migrating away from the planet
- This moon may have pulled the planet on its side before colliding with it
The unusual properties of the ice giant Uranus have long puzzled scientists.
But now experts think they have an explanation for why the seventh planet has an axis of rotation so crooked from the Sun that it might as well be lying.
They say a mysterious moon migrating away from Uranus may have pulled the planet onto its side, causing it to have a whopping 98-degree tilt from the orbital plane.
Researchers at the National Center for Scientific Research in France claim it didn’t even have to be a large moon to achieve this effect.
Although a larger satellite would be more likely to blame, it could have been something half the size of our own satellite.
The odd tilt isn’t the only oddity of Uranus. It also spins clockwise, which is the opposite direction from most other planets in our solar system.
Previous research has shown that this strange behavior could be due to Uranus being hit by a massive object roughly twice the size of Earth billions of years ago, causing the planet to tip over.
Theory: The unusual properties of the ice giant Uranus have long puzzled scientists. But now experts think they have an explanation for why the seventh planet has an axis of rotation so crooked from the Sun that it might as well be lying
WHAT DO WE KNOW ABOUT URANUS?
Uranus was discovered by William Herschel in 1781 and is named after the Greek god of the sky, Ouranos.
It is 1.84 billion miles from the Sun and orbits every 84 years. Its largest moons are Miranda, Ariel, Umbriel, Titania, and Oberon.
It rotates on its axis once every 17 hours and 14 minutes.
It has the coldest temperatures of any planet in the solar system with a minimum temperature of -371F.
It has a series of dark, very thin colored rings surrounding it.
The “catastrophic” collision shaped the evolution of Uranus and could explain its freezing temperatures, according to the 2018 study.
The problem with this theory, however, is that it doesn’t explain why its neighboring planet Neptune shares a number of similarities, including masses, rotation rates, atmospheric dynamics and composition, and unusual magnetic fields.
This prompted scientists to try to find other explanations, such as a wobble that could have been caused by a giant ring system or moon in the early history of the solar system.
A few years ago, astronomer Melaine Saillenfest — who led the new study — found something interesting about Jupiter.
The inclination of the gas giant could increase from the current slight 3 percent to around 37 percent in a few billion years. The reason? The emigration of its moons.
They then looked at Saturn and found that its current tilt of 26.7 degrees could be the result of the rapid migration of its largest moon, Titan.
Researchers theorized that this may have happened while having very little effect on the planet’s rotation rate.
This prompted the team to run simulations of a hypothetical uranium system to see if a similar mechanism could explain its strange behavior.
They found that a hypothetical moon with a minimum mass of about half the mass of Earth’s moon Uranus could tilt toward 90 degrees if it rotated more than 10 times the radius of Uranus at a rate of more than 6 centimeters per year wandered.
However, a larger moon, comparable in size to Jupiter’s Ganymede, would be more likely to produce the tilt and roll that we see in Uranus today.
The problem with the theory is that the minimum mass – about half an Earth’s moon – is about four times the combined mass of the currently known Uranium satellites.
But the researchers also believe they have an answer for this.
A larger moon, comparable in size to Jupiter’s Ganymede (pictured above left), would be more likely to produce the tilt and roll we see in Uranus today
They say that this hypothetical moon could have become destabilized at an inclination of about 80 degrees, which would have triggered a chaotic phase for the spin axis, ending when it eventually collided with Uranus, effectively “petrifying” the planet’s axial tilt and rotation. .
“This new picture for the tilt of Uranus looks quite promising to us,” they wrote.
“To our knowledge, this is the first time that a single mechanism has been able to tilt Uranus and petrify its spin axis in its final state without causing a violent impact or other external phenomena.
“The majority of our successful runs culminate at the location of Uranus, which appears to be a natural outcome of the dynamics.
“This image also seems appealing as a generic phenomenon: Jupiter is about to begin the tipping phase today, Saturn may be halfway there, and Uranus would have completed the final phase with the destruction of its satellite.”
The pending work has been accepted into the journal Astronomy & Astrophysics and made available on the preprint resource arXiv.
HOW DOES URANUS’ MAGNETIC FIELD COMPARE TO EARTH’S?
A recent study analyzing data collected more than 30 years ago by the Voyager 2 spacecraft has found that Uranus’ global magnetosphere is unrelated to that of Earth, which is known to be almost identical aligned with the axis of rotation of our planet.
Shown is a Hubble false-color view of Uranus
According to Georgia Institute of Technology researchers, this alignment would result in behavior very different from what is observed on Earth.
Uranus lies and rotates on its side, keeping its magnetic field tilted 60 degrees from its axis.
As a result, the magnetic field “staggers” asymmetrically to the solar wind.
As a result, the magnetic field “staggers” asymmetrically to the solar wind.
When the magnetosphere is open, it lets in the solar wind.
But when it closes, it forms a protective shield against these particles.
The researchers suspect that the reconnection of the solar wind occurs upstream of Uranus’ magnetosphere at different latitudes, causing the magnetic flux to close in different parts.