Saturn’s getting easier to see, though its rings are not

Spotting Saturn in the night sky, plus a quake shifts the Earth in Japan

August 13, 2024 Issue #760

Pic o’ the Letter

A cool or lovely or mind-bending astronomical image/video with a description so you can grok it

It’s been a while since I’ve seen Saturn in my sky; up until recently it’s been rising a bit late and wasn’t high in the sky until after midnight. Plus, I live in a forest with limited horizon (and by that I mean no horizon; I have to get in the car and drive a bit to get open skies) so it’s been behind tree trunks for months. 

However, it’s rising earlier every night, and will soon grace our evening skies for easy visibility. On September 8 it reaches opposition, when it’s opposite the Sun in the sky, so it rises at sunset. That means it’s up all night. Even better, it means Earth and Saturn are as close as they can be in their orbits (you can draw a relatively straight line from the Sun through Earth to Saturn), so it looks biggest and brightest as it will all year. To take a look, go out around midnight and look to the south-southeast; it’ll be the brightest object in that direction. 

Expert solar-system-object-photographer (and seemingly part magician) Damian Peach took a fantastic shot of the ringed planet on July 24, 2024, and it’s magnificent:

Saturn appears as a slightly flattened ellipse, with dozens of parallel bands across its face. The rings are nearly edge-on, the orange disk of Titan is to the upper right, and a small black shadow of the moon Dione is at the lower right.

My favorite planet beside the one I’m currently sitting on. Credit: Damian Peach

Whoaaaaa. In this image Saturn’s bands and zones — the parallel stripes — really stand out. Those are wind patterns moving around the planet, just like Jupiter’s. Unlike the larger planet, though, Saturn’s atmosphere has a lot of haze, suspended particles that blur out the clouds below, muting the bands. It generally looks paler than Jupiter, but here Peach processed the image in a way that makes the stripes more obvious.

You can also see the giant aptly named moon Titan to the upper right. Perspective is funny: Saturn’s rings and Titan’s orbit are both almost exactly above Saturn’s equator, but Titan looks like it’s well above the rings. That’s an illusion due to trigonometry. There’s also the shadow of the moon Dione on the lower right. I think the moon should be just below the rings on the right, but I can’t see it in this image. It may be too faint to see against Saturn’s brightness.

And the rings! Saturn is tilted with respect to its orbit by about 26°, similar to Earth’s 24° tilt. From Earth we see the planet at different angles as it orbits the Sun, and right now we’re approaching the time when Saturn’s rings will look edge-on (note how foreshortened they already look here). In March 2025 we’ll see them exactly edge-on, and they’re so thin (just a few dozen meters thick in some places, as people who have read my book Under Alien Skies already know) they’ll essentially disappear (though this happens when Saturn is close to the Sun in the sky, so seeing it will be extremely difficult). Even now they’re so close to edge-on that details are difficult to spot; even the wide Cassini Division (the dark gap about 2/3rds of the way to the outer edge) is not obvious.

 Then, a few months later in May, Saturn will be at equinox, when the Sun is directly over its equator. When that happens the rings will cast a knife’s-edge shadow on the planet. It’s the autumnal equinox for the northern hemisphere, with winter approaching as the planet’s axis slowly tips away from the Sun over the next few years (one Saturn year is about 29 Earth years). By then the rings will have started opening up to us from Earth again, and in a few years they will be more like what you’re used to seeing; wide and bright. In fact, the rings are so reflective that when they’re as thin as they are now Saturn is noticeably dimmer than when the rings are more tipped to us! So when you go out to see Saturn over the next few months, keep that in mind. As bright as it is, it’ll be even brighter in the years to come. 

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