- In 18 months, Saturn’s iconic rings will no longer be visible from Earth
- The planet’s tilt means that the rings will appear side on and vanish from view
Time is running out for a last look at Saturn’s rings, with only 18 months left before they disappear from view.
NASA has confirmed that stargazers have until 2025 to view the iconic structures before Saturn tilts edge-on with Earth, turning the vast rings into an almost invisible line.
Saturn’s rings are enormous structures, extending up to 43,500 to 87,000 miles (70,000 to 140,000 km) in places.
Yet they are almost paper thin in comparison, at only 30ft (10m) tall in the main rings, making them disappear when viewed side-on.
The rings will not be gone for good, however, and will tilt back towards Earth during the next phase of Saturn’s 29-year orbit.
Due to a tilt in its orbit, Saturn wobbles slightly towards and away from the sun throughout its orbital period.
This means that, for a short period every 13.7 to 15.7 years, Earth sees the planet perfectly from the side.
At 746 million miles (1.2 billion km) away, this makes the rings appear to vanish from our perspective.
As it stands, Saturn’s rings are tilted downwards towards Earth at an angle of 9 degrees and by 2024 that angle will have reduced to just 3.7 degrees.
The last time this rare astronomical event occurred was in September 2009, and before that, it had not occurred since February 1996.
Astronomers will not get the chance to view Saturn from this unique perspective again until October 2038.
Earth passing through the edge-on-view might make Saturn’s rings impossible to see, but astronomers say it will be an excellent time to watch some of the planet’s 156 moons.
After passing through the edge-on view, Saturn’s rings will quickly return to view as the planet’s South Pole tilts to face Earth.
This will bring the bottom of the rings into sight of Earth – a view which has not been visible for over a decade and a half.
The rings will continue to become more visible until 2032 when Saturn reaches its maximum tilt away from Earth.
Saturn’s rings are made mainly of chunks of ice, rock, and dust that have been trapped by the planet’s gravitational pull.
While some of the particles are tiny – no bigger than grains of sand – some of the chunks of ice can be as big as a house and a few are even as large as mountains.
It is currently believed that the rings are formed from the shattered remains of comets, asteroids, and moons that were torn apart by Saturn’s powerful gravity.
Exactly when they were formed remains a topic of some debate among astronomers with competing theories suggesting they are as old as the solar system or relatively young.
While the disappearance of Saturn’s rings will only be temporary this time, scientists warn that the rings may one day be gone for good.
NASA’s Cassini probe, which flew through Saturn’s rings 22 times before its 2017 death dive into the planet, found that the rings were vanishing at a ‘worst case scenario rate’.
Cassini found that the rings were losing somewhere between 880lbs (400kg) and 6,000lbs (2,800kg) of mass every single second
Dr James O’Donoghue, a planetary scientist at the Japan Aerospace Exploration Agency said: ‘We’re still trying to figure out exactly how fast they are eroding’.
In a phenomenon known as ‘ring rain’, radiation from the Sun causes particles in the atmosphere to gain an electrical charge.
This, in turn, causes the particles to bind with gas in Saturn’s atmosphere and become pulled out of the rings by the planet’s gravity.
Dr O’Donoghue added: ‘Currently, research suggests the rings will only be part of Saturn for another few hundred million years.’
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
