AMATEUR STARGAZERS WILL be able to catch a glimpse of Jupiter at its biggest and brightest this evening as it comes within its closest point of Earth in nearly 60 years. 

The largest planet in our solar system will come within 590 million kilometres of Earth during an event known as ‘opposition’.

Opposition occurs when Jupiter, Earth and the sun align in such a way that both planets are on the same side as the sun, with Earth in the middle.

As Jupiter reaches opposition while rising from the east at the same time the sun sets in the west, it will also be at its closest approach to Earth since 1963. 

Speaking to The Journal, David Moore of Astronomy Ireland said that Jupiter is at opposition about every 13 months, the length of time it takes for Earth to orbit the sun.

“It takes Jupiter 12 years to go around the sun. We catch up with it every 13 months, so if you like, the sun, Earth and Jupiter will be in a straight line and that’s when we’re closest,” he said.

“It’s actually the brightest planet in the sky, and because of opposition, when you’ve got the sun, Earth and Jupiter lining up, that means that Jupiter is visible all night. As soon as the sun sets, Jupiter rises by definition. It’s at its highest at midnight and then it sets just as the sun is rising, so it’s visible all night long.”

Stargazers: Jupiter will make its closest approach to Earth in 59 years! Weather-permitting, expect excellent views on Sept. 26. A good pair of binoculars should be enough to catch some details; you’ll need a large telescope to see the Great Red Spot. https://t.co/qD5OiZX6ld pic.twitter.com/AMFYmC9NET

— NASA (@NASA) September 23, 2022

The sun is expected to set at around 7.15pm in Ireland this evening, when people will be able to see Jupiter. Met Éireann are forecasting a dry night with clear spells in most areas, with some isolated showers in the northeast of the country. 

“We’d certainly encourage people to go outside and look up,” Moore said, adding that the planet will be visible for the next few months.

How to see it

While the gas giant will be visible to the naked eye, those with binoculars and telescopes will have the best view.

“With the naked eye, if you go out when it gets really dark, the very bright star-like object you’ll see – it’s about ten times brighter than the next brighter star in the sky – that’s Jupiter. Even in a city, you’re going to see it with all the streetlights on,” Moore said.

Those with binoculars will have a better view of Jupiter, and will also be able to see the four largest moons orbiting the planet if they keep them steady.

“They’re at least as big as our moon, some of them are bigger, and you can see those in binoculars. If you hold your binoculars really still and look at Jupiter, you’ll see between one and four tiny stars next to it and they’re its moons.”

The four giant moons, Io, Europa, Ganymede, and Callisto, are referred to as Jupiter’s Galilean satellites. They are named after Galileo Galilei, who discovered them in the 17th century. 

“When Galileo turned the first telescope on Jupiter 400 years ago, he saw these little stars next to it and figured out that they were going around Jupiter as he watched them from night-to-night, and that’s what led him to believe the Earth isn’t at the centre of the universe. Everything was supposed to go around the Earth. It didn’t. In the case of those moons, they went around Jupiter,” Moore said.

“Of course if you’ve got a telescope, well the moons are dead easy. Even the cheapest telescope will show the moons, because a pair of binoculars can do it.”

Anyone with a larger telescope will also be able to glimpse Jupiter’s cloud belts as well as the Great Red Spot, a large spinning storm that has been raging on the planet for hundreds of years.

Moore also said that Mars will be “taking over” towards the end of the year, when it is expected to come especially close to the Earth in December.

“Mars will be closer than it’s been for over two years now, and it won’t be this close for another two years. Jupiter will still be in the sky at that time. The two of them will be arguing with each other over who’s the brightest, and both of them will be ten times brighter than the brightest star in the sky.”