The moons around Uranus are on a collision course to total destruction
Two pairs of Uranus’ 27 moons look to be on a collision course and are expected to hit into each other in two successive crashes.
While studying Uranus’ rings using data from NASA’s Voyager 2 flyby of Uranus in 1986, researchers from the University of Idaho and Wellesley College found the rings have a strange-shaped orbit, caused by the gravitational pull of the moon Cressida.
Voyager 2 passed Uranus on 24 January 1986, at a distance of 81,500km. From that distance, it was able to get a good look at the planet’s weird atmosphere.
Due to what’s thought to have been a collision with an Earth-sized body during the early formation of the solar system, Uranus has an axial tilt of 97.77 degrees, meaning that it spins on its side with its poles where you’d normally expect to find another planet’s equator.
It is thought the inner rings were formed when previous moons of Uranus, which are among the most tightly packed in the solar system, crashed into each other.
When the team plotted the path of Cressida they found it is due to cross paths with the orbit of the moon Desdemona, which currently orbits only 560 miles (900km) from Cressida’s orbit. However, astronomers aren’t panicking just yet. The first pair isn’t expected to collide for at least four million years’ time, and the second crash will later follow.
“Desdemona could collide with either Cressida or Juliet within the next 4 − 100 million years, depending on the masses of the satellites involved,” the paper says.
Cressida and Desdemona are members of the most tightly packed system of moons in our solar system called the Portia group. “These satellites are thought to be unstable on short timescales compared to the age of the solar system,” the authors said.
The paper, which has not been published yet but was posted on the preprint server arXiv, also found the same to be true for Cupid and Belinda. These moons are also members of the group, and it is predicted they will collide later.
The group suggested a mission to Uranus should be the next step in order to further understand Uranus’ moons compositions and predict their fate.
The only spacecraft to have gone anywhere near Uranus is Voyager 2, which captured images of the planets as it swung past both on its journey out of the solar system.
Voyager 2 was actually launched before Voyager 1, on 20 August 1977, and it’s still sending signals back to us today, almost 38 years later, as it enters interstellar space – making it one of the most distant man-made objects in the universe.
Image: Wikimedia Commons