Month's planets

Jupiter is not only the king of the Solar System, but the ruler of the dawn sky alongside Mars and Saturn

Jupiter is not only the king of the Solar System, but the ruler of the dawn sky

While many sky-watchers and amateur astronomers will still be focusing their attention on Venus shining in the evening sky, there is another planetary treat to enjoy in the sky before sunrise. Early risers will see Jupiter, the largest planet in the Solar System, as a very bright ‘morning star’ throughout this month. This giant world, so huge it could contain over a thousand Earths with room to spare, can be found shining above the southeastern horizon in the early hours, lingering near the Sagittarius-Capricornus border.

At the start of our observing period Jupiter will be rising around 01:30, and as the weeks pass its visibility will improve. By mid-June it will be rising well before midnight and will technically become an evening object.

Through the month ahead Jupiter will be an easy naked-eye target, one of a chain of nakedeye planets stretched across the southeastern sky like beads on a wire. To Jupiter’s left you’ll find the Ringed Planet, Saturn, noticeably fainter than Jupiter and shining with more of a warm, yellow hue, and further over to the left and lower in the sky Mars will be shining brightly with its characteristic orange colour.

In photographs taken by the famous Hubble Space Telescope and before that by the Voyager and Galileo space probes, Jupiter’s surface is shown criss-crossed by multiple light and dark bands of cloud. Red, brown and orange storms whirl around and past each other, and streamers of garishly coloured gas, teased out by strong upperatmosphere winds, can also be seen. The largest amateur telescopes will resolve some of these features, though obviously in less detail. However, even a simple pair of binoculars will be more than good enough to show you Jupiter’s four largest moons – the so-called Galilean Moons named after their discoverer, Galileo – looking like tiny pinprick stars close to Jupiter itself.

During the month ahead Jupiter won’t just have company of the planetary kind either. On 8 June early risers will be rewarded with the sight of the giant planet shining just nine degrees to the upper left of a very pretty almost-full Moon, and the following morning the giant planet will be shining less than six degrees to the Moon’s upper right, both great observing opportunities.