Jupiter at opposition: Mighty gas giant set to look like ‘bright star’ in sky

The mighty gas giant will appear to the naked eye as “a bright star, though it won’t twinkle like the stars” on the evening of Thursday August 19.

This is because Jupiter will be at “opposition”, meaning that, as Earth passes between the Sun and Jupiter, the planet will appear opposite the Sun.

Bryony Lanigan, an astronomer at the Royal Observatory Greenwich, said: “When a planet is at opposition, it is on the opposite side of the Earth to the Sun – if you were looking down on the Solar System from above and drew a line from Jupiter to the Sun, when Jupiter is at opposition it would pass through the Earth.

“This doesn’t necessarily mean that the planet is at its closest point to the Earth – because of the elliptical nature of planetary orbits, this may occur a day or two either side.”

Ms Lanigan added that planets are usually in opposition for a very short length of time but, during that time, they are visible to the naked eye.

She told the PA news agency: “Jupiter should be visible low above the south-eastern horizon from sunset on the days around opposition on the 19th, but if planet-hunters wait until a few hours after sunset then it will have risen a little higher – around 20-25 degrees altitude – and so will be easier to spot.”

Jupiter’s opposition takes places just days before the full moon, which is on August 22.

Ms Lanigan added: “While the sky will not be fully dark, the Moon will not be intruding too much on astrophotographers’ views.”

Meanwhile, those looking for Jupiter in the night sky may catch a glimpse of Saturn as well.

Ed Bloomer, also a Royal Observatory Greenwich astronomer, told PA: “Both planets are fairly low on the horizon, so try and find an observation spot free from tall buildings or trees when looking in that direction.

“And another bonus is that the waxing moon is – relative to the planets – sweeping eastwards over those few days.

“There’s a chance you could get a good photograph featuring stars, planets and the Moon.”

He said those looking through telescopes may catch a glimpse of Jupiter’s moons as well as Saturn’s rings.

Mr Bloomer added: “The Galilean moons (Jupiter’s four largest moons – Io, Europa, Ganymede, and Callisto) will look like pinpricks of light in orbit around Jupiter.

“Around Saturn you may be able to make out the rings, and even major divisions within the rings.

“If your telescope is really good, perhaps you’ll even make out the swirling clouds of Jupiter’s upper atmosphere.”