Will Saturn’s rings really ‘disappear’ by 2025?

If you can get your hands on a telescope, there are few sights more spectacular than the magnificent ringed planet… Saturn.

Currently, Saturn is clearly visible in the evening sky, at its peak just after sunset. Now is the perfect time to use a telescope or binoculars to get a good look at the sixth planet in the solar system and its famous rings.

But in recent days, numerous articles have been circulating like wildfire on social networks. The rings of Saturn, these articles claim, disappear quickly – and will disappear by 2025!

So what’s the story? Could the next few months, before Saturn disappears into the evening sky, really be our last chance to see its mighty rings?

The short answer is no. While it is true that the rings will become almost invisible from Earth in 2025, this is neither a surprise nor a reason to panic. The rings will “reappear” shortly after. Here’s why.

Tilt and tilt of the Earth

To understand why our view of Saturn changes, let’s start by considering Earth in its constant journey around the Sun. This journey takes us through the seasons – from winter to spring to summer to fall and back again.

What are the causes of the seasons? Simply put, the Earth is tilted to one side as seen from the Sun. Our equator is tilted about 23.5 degrees relative to the plane of our orbit.

The Earth has seasons because its axis is tilted. The axis always points in the same direction as our planet orbits the Sun.(Supplied: Bureau of Meteorology)

The result? As we move around the Sun, we alternately tilt one hemisphere then the other towards our star. When your home hemisphere is tilted more toward the Sun, your days are longer than your nights and you experience spring and summer. When you’re tilted, you get shorter days and longer nights, and you experience fall and winter.

From the Sun’s perspective, Earth appears to “nod” up and down, alternately showing its hemispheres as it moves around our star. Now let’s move on to Saturn.

Saturn, a giant tilted world

Just like Earth, Saturn has seasons, but more than 29 times longer than ours. Where Earth’s equator is tilted 23.5 degrees, Saturn’s equator has a tilt of 26.7 degrees. The result? As Saturn moves in its 29.4-year orbit around our star, it also appears to nod its head up and down when viewed from Earth and the Sun.

What about the rings of Saturn? The planet’s enormous ring system, made up of chunks of ice, dust and rock, stretches an immense distance — just over 280,000 km from the planet. But it’s very thin – in most places, only a few dozen meters thick. The rings orbit directly above Saturn’s equator and are therefore also tilted relative to the plane of Saturn’s orbit.

The planet’s enormous ring system, captured here by NASA’s Hubble Space Telescope, is made up of chunks of ice, dust and rocks.(NASA, ESA, A Simon (GSFC), MH Wong (University of California, Berkeley) and the OPAL team via Reuters )

So why are Saturn’s rings “disappearing”?

The rings are so thin that, seen from a distance, they seem to disappear when placed edge-on. You can easily visualize this by grabbing a sheet of paper and rotating it until it is on the edge: the paper almost disappears from view.

As Saturn moves around the Sun, our perspective changes. For half the orbit, its northern hemisphere is tilted toward us and the north face of the planet’s rings is tilted toward us.

When Saturn is on the far side of the Sun, its southern hemisphere points toward us. For the same reason, we see the south face of the planet’s rings tilted towards us.

The best way to illustrate this is to take your sheet of paper and hold it horizontally – parallel to the floor – at eye level. Now move the paper toward the floor a few inches. What do you see? The top side of the paper appears. Move the paper up, across your eye line, to hold it above you and you will be able to see the underside of the paper. But as it moves to eye level, the paper will virtually disappear.

This is what we see with Saturn’s rings. As the seasons on Saturn progress, we move from tilting on the south side of the rings to tilting on the north side. Then the planet recedes, revealing the southern side again.

Twice each Saturnian year we see the rings break away and they virtually disappear from view.

This is what will happen in 2025 – the reason Saturn’s rings will apparently “disappear” is because we will look at them wrong.

This happens regularly. The last time was in 2009 and the rings gradually became visible again, over a few months. The rings will be visible again in March 2025. They will then gradually return to the view of large telescopes, before disappearing again in November 2025.

Thereafter, the rings will gradually become more and more evident, first reappearing at the largest telescopes over the following months. Nothing to worry about.

If you want to see Saturn’s rings clearly, now is your best chance, at least until 2027 or 2028!

Jonti Horner is Professor of Astrophysics at the University of Southern Queensland. This piece first appeared on The conversation.