THE BIG THREE

The top sights to observe or image this month

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Mercury, Venus and Jupiter

BEST TIME TO SEE: From 03:30 BST (02:30 UT) all month. Closest approach on 12 August

Venus is the brightest planet that can be seen from Earth. At its peak brightness, when 22% illuminated, Venus approaches mag. -5 – that's so bright that it can cast shadows, if conditions allow. Jupiter is bright too, able to reach mag. -2.94 under optimum conditions (coincidentally, that's the same maximum brightness as Mars). Mercury isn't far behind, able to attain a peak magnitude of -2.48.

Of course, catching all four near one another at peak brightness can't actually happen, as Jupiter and Mars need to be opposite the Sun, a position that Mercury and Venus can never attain. That's not to say that a meeting between some of these worlds isn't impressive – and this month, you'll have a chance to take a look and see for yourself. On 1 August, it's just mag. -3.9 Venus and mag. -1.8 Jupiter that appear together in the dawn twilight. They appear a little under 11° apart on this date, both being above the horizon just after 03:00 BST (02:00 UT), but you'll need to give them a bit more time to get to a decent altitude for viewing, say from around 04:00 BST (03:00 UT).

Over the course of the following mornings, the apparent gap between them closes due to Venus making a dash to the east, running under the stars that form the Gemini twin Castor's foot. Catch Venus early enough on 2 August, when the sky is still dark, and you might be able to see it 2.3° south of the open cluster M35. Binoculars will give the best view of this meeting.