See Saturn disappear behind the Moon in the New Year. How to see the lunar occultation event

See Saturn disappear behind the Moon in the New Year. How to see the lunar occultation event

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Published: January 3, 2025 at 10:53 am

There's a lunar occultation of Saturn visible on 4 January 2025, during which the ringed planet will seem to disappear behind the Moon, before reappearing on the other side.

The best time to see the event will be 4 January, 16:30–18:30 UT.

Lunar occultations of planets are fairly infrequent affairs. The last lunar occultation of Saturn occurred on
21 August 2024
, although you’d need to go back to 2007 for one before that which was visible from the UK. 

While August’s event involved a 97%-lit waning gibbous Moon moving in front of Saturn in the brightening dawn twilight, the transit on 4 January occurs in the early evening sky, the occulting Moon being a 25%-lit waxing crescent. 

Chart showing the lunar occultation of Saturn on 4 January 2024. Credit: Pete Lawrence
Chart showing the lunar occultation of Saturn on 4 January 2024. Credit: Pete Lawrence

How to see the lunar occultation of Saturn

Saturn’s disappearance occurs under darkening skies after sunset. The Moon should be easy to spot around 16:30 UT, one-third of the way up the sky, just west of south.

It’ll also be 12.5° east-northeast of brilliant mag. –4.3 Venus at this time.

Saturn will be a lot dimmer than Venus at mag. +0.8, only becoming visible just left of the Moon as the sky darkens.

Lunar occultation of Saturn captured by Josh Dury from Somerset, UK, 21 August 2024. Credit: Josh Dury
Lunar occultation of Saturn captured by Josh Dury from Somerset, UK, 21 August 2024. Credit: Josh Dury

Hopefully, the event will be assisted by the presence of strong earthshine, the effect that makes the night side of the Moon glow slightly.

It’s caused by light from the Sun reflecting off Earth, hitting the Moon’s night surface and reflecting back to Earth.

If it is visible, it’ll give you an excellent indication as to where and when occultation disappearance will occur.

If not, you’ll need to ‘round the circle’ using your imagination and the visible part of the lunar crescent.

Earthshine on the Moon will help you see the lunar occultation of Saturn on 4 January 2025. Credit: Pete Lawrence
Earthshine on the Moon will help you see the lunar occultation of Saturn on 4 January 2025. Credit: Pete Lawrence

Occultation disappearance occurs at 17:18 UT, a time correct for the centre of the UK, but one which may vary by a few minutes depending on your location in the country.

The Moon is close enough to exhibit parallax, where its position shifts slightly from different locations, affecting the timings slightly. 

Disappearance behind the Moon’s dark edge takes 52 seconds.

Lunar occultation of Saturn
Credit: Jamie Cooper/SSPL/Getty Images

Not just Saturn...

Interestingly, HIP 114054, a mag. +6.7 star, will be located 36 arcseconds southeast of Saturn’s centre and undergoes occultation disappearance at the same time as the planet.

You should be able to see Saturn’s largest and brightest moon, Titan, undergoing occultation disappearance 3 minutes 9 seconds after Saturn. 

Reappearance begins around 18:26 UT (centre of the UK time), with the western section of Saturn’s rings appearing ahead of the planet’s globe.

This was a particularly striking thing to see during the August 2024 occultation and should be equally as dramatic for the January 2025 event. 

The lunar occultation of Saturn, 22 May 2007. Credit: Pete Lawrence
The lunar occultation of Saturn, 22 May 2007. Credit: Pete Lawrence

Saturn will take 65 seconds to fully reappear. Don’t forget to look out for HIP 114054 reappearing along with Saturn.

Titan reappears from behind the Moon’s bright limb 3 minutes 31 seconds after Saturn, bringing the event to a close.

Occultation reappearance occurs under darker sky conditions, with Saturn 23° up above the southwest horizon.

If you observe the lunar occultation of Saturn on 4 January 2025, share your images and observations with us by emailing contactus@skyatnightmagazine.com.

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