2 things to look for in southern skies

Stargazers in the Southern Hemisphere will be treated to both a comet, and a gathering of almost all the planets, in the night sky over the next week.

Comet C/2024 G3 (ATLAS) is glowing after its close encounter with the Sun, and will be best spotted at sunset over the next few days.

Meanwhile, the planets are congregating on one side of the Sun, and all of them except Mercury will be visible at night.

Comet C/2024 G3 (ATLAS) was discovered in April last year, on its way into the inner Solar System.

The comet passed perihelion, when it’s closest to the Sun, on 13 January, and is now on its way back out.

Its proximity to the Sun will make the comet both easier and harder to see: the Sun’s heat causes the comet’s icy chunks to flare out in a bright tail, but it’s so close to the Sun that it’s hard to make out with the naked eye.

But viewers in the Southern Hemisphere should be able to catch a glimpse at sunset over the next few days. Look west or southwest just after sunset – the comet should be grazing the horizon, almost directly below Venus.

Stargazing apps like SkyView or Star Walk can help you get your bearings. The website and app Stellarium has been tracking the comet closely.

If the comet proves too tricky to see, you can always use these apps to find planets instead.

In the next week, depending on cloud cover, all of the planets except Mercury will be glowing in the night sky simultaneously.

“The Solar System is putting on a great show to enjoy on upcoming summer evenings. It’s not often that we get to see all these planets together,” says Dr Laura Driessen, an astrophysicist at the University of Sydney.

You’ll need a telescope to see Uranus and Neptune, but the other 4 planets – Venus, Mars, Jupiter, and Saturn, will all be visible with the naked eye.

Diagram of planetary alignment — The predicted view of the 4 visible planets from Sydney at 9:30pm on 21 January. Other cities will have different timings – check a stargazing app or website to find yours. Credit: University of Sydney

“It looks like Tuesday 21 January will be the best viewing evening as the Moon wanes, with the planets visible together until mid-February,” says Driessen.

“Weather permitting, you can see them for a few hours from when the Sun sets.”

The planets will be scattered across the night sky, with Venus and Saturn close to each other near the horizon.

And if you’re keen to get Mercury in on the picture, it should be visible from the group too by late February.