How to... Photograph a conjunction

When two planets shine close together in the sky it’s always a special sight. But when the slim crescent Moon crashes the party in the sky after sunset the result is something truly magical…

The Moon, Mercury and Mars make an appealing target

As they wander along the ecliptic, it’s inevitable that pairs of planets will sometimes come together, appearing close in the sky. Astronomers call such a celestial close encounter a ‘conjunction’, and they are one of the easiest and prettiest things a stargazer can see. Such an event might happen several times a year, and amateur astronomers look forward to these because they look so striking.

If both planets involved are bright naked-eye objects, such as Venus and Mars, or Jupiter and Saturn, they can appear like a lovely ‘double star’ in the sky when they’re at their closest. Sometimes pairs of planets appear so close together that they are actually too close for the naked eye to split – then they are best viewed through binoculars or even a small telescope.

Occasionally a crescent Moon will drift into the area of a planetary conjunction too, and then what would have been a special sight becomes something truly spectacular, beautiful enough to stop people in their tracks as they go about their business. This is what will happen on the evening of 5 June, when – if your sky is clear – you’ll be able to see Mercury and Mars shining close together in the northwest after sunset with a beautiful fingernailclipping-thin crescent Moon close by too.

You won’t need a telescope to see this grand celestial gathering, as all three of the worlds involved will be clearly visible to the naked eye. However, if you have a pair of binoculars they will really improve your view, making Mars and

Mercury look much brighter, and you’ll also be able to see the subtle lavender-pink glow of ‘Earthshine’ on the unilluminated part of the Moon’s face.

As attractive as this scene will be visually, it will also be a photographic treat. To capture it you’ll need to use a DSLR on a sturdy tripod, and you’ll also need a clear view to the northwest, with as flat a horizon as possible. Mercury will be very low in the sky and any trees, buildings or hills in that direction will almost certainly obscure it.

“One of the easiest and prettiest things a stargazer can see”