What’s that bright star in the east?

There are two really bright stars in the evening sky in the run-up to Christmas. But neither are actually stars – they are the planets Mars and Jupiter. And this December, Mars is making a close approach to Earth, and won’t be as close again until 2031.

Currently, Mars is in the eastern sky, while Jupiter is over to the west. Compare the two and you’ll notice straight away that Mars is a different colour from the creamy-white Jupiter. 

Although it’s known as the Red Planet, it appears more of a salmon colour in the sky.

Mars in the evening sky in the constellation of Taurus. Photo: Robin Scagell

Mars was at its closest on 1 December, and amateur astronomers are getting good views of the planet. Any telescope that will magnify around 100 times will show the planet’s disc and its dark markings. 

At the start of December Mars is 82 million km away from Earth, increasing to 95 million km by the New Year. During the month the planet slips away from Earth, but it’ll remain visible for many months to come. 

Jupiter is also an easy target for small telescopes, and the Solar System’s giant planet appears bigger than Mars. Even binoculars will show its four main moons, and if you look again at the planet on a different night you’ll see that they have moved in their orbits. Not all four are always visible as one or more may be in front of or behind Jupiter.

Recent photos of Mars and Jupiter by Martin Lewis, shown at their comparative sizes as viewed in the sky. The whitish areas of Mars are not its polar caps but are clouds over the colder polar regions. 

Mars disappears

On Thursday 8 December there will be a special event – the Moon will go in front of Mars! This happens every couple of years or so, so isn’t especially rare, but it’s a fascinating sight as seen through a telescope, as it takes only 30 seconds for Mars to be completely covered by the Moon. The only downside is that this December’s event takes place between about 4:50 am and 5 am, so not very socially friendly timing! The reappearance of Mars occurs an hour later than its disappearance. The farther north and east you are in the UK, the earlier the timings.

Simulation of Mars and the Moon on the early morning of Thursday 8 December, as depicted by Stellarium software.

The video below was taken during the disappearance of Mars on 8 December.