Jupiter and Venus, two of the solar system’s brightest planets, will appear to almost touch in a rare celestial spectacle this weekend.

Although in reality they will be millions of miles apart, for stargazers on Earth they will appear to be close enough to almost collide in a planetary conjunction that occurs once a year.

However, this year Jupiter and Venus will look much closer together than usual and should be visible with just a pair of binoculars or even the naked eye. If you miss it, you will have to wait another 17 years for a repeat performance.

As well as the extraordinary planetary conjunction on display, Saturn and Mars will also appear to be in a straight line with Jupiter and Venus.

Brad Tucker, an astrophysicist at the Australian National University, said the planets had been moving closer together over the past couple of weeks.

“Although Venus and Jupiter get close to one another every few years, this time there is also Mars and Saturn in the mix which is pretty rare,” he said.

“If you have a telescope, a pair of binoculars or a decent camera, then you’ll get an even better view.”

Despite their close appearance, the planets will actually be 430m miles apart in orbit.

The peak time to see the event in the UK was at about 5am on Saturday from a high vantage point with a clear eastern horizon. However, it will still be visible on Sunday and the days that follow as the planets move apart again.

From London, it will be almost impossible to witness but the farther west in the country you are, the closer the planets will appear to be.

Observers in Sydney, Australia, will have a clear view with the pair of planets due to rise in the east at about 3.30am local time on 1 May.

“The planets will differ in their brightness,” the chief stargazer at the Society for Popular Astronomy, Prof Lucie Green, told BBC News.

“Venus is brighter than Jupiter so it will look dazzlingly bright when you see it. Jupiter will be slightly fainter, about one-sixth of the brightness of Venus.”

Venus, Jupiter, Mercury and Mars came together in the eastern sky in a formation not likely to be seen again until 2040, during the early sunrise hours of 13 May 2011.