Mercury is generally something of a challenge to observe, but the run-up to a particularly favourable easterly elongation occurring on 30 July provides ample opportunities for locating the innermost planet in the evening sky — particularly from the Southern Hemisphere, where a prominent celestial marker in the form of a 2-day-old Moon passes close by on 25 July.
Skywatchers in the UK and Western Europe should cast their gaze low in the southern sky late into the evening of Thursday 6 July to see the 12-day-old waxing gibbous Moon in conjunction with ringed planet Saturn. The pair are separated by just 3½ degrees, nicely framed in a typical 10×50 binocular. For telescope users, the night of 6—7 July is also good for spotting Saturn’s bright moons. We show you what to look for and where.
Observer’s in the UK and Western Europe should look low to the southwest an hour after sunset on Friday, 30 June to glimpse the almost first quarter Moon a low-power binocular field of view to the right of Jupiter in bright twilight. The following night finds the waxing gibbous Moon forming a near isosceles triangle with the planet and first-magnitude star Spica in Virgo.
Skywatchers in the UK looking to the south-southeast shortly before midnight on Friday 9 June can see the rising full Moon just 2½ degrees above Saturn, the pair fitting comfortably in the same field of view of binoculars and telescopes magnifying less than 20×. Saturn is closest to the Earth for this year on 15 June, so here is our quick observing guide to the ringed planet at its best.
Jupiter now lies highest in the UK sky at sunset, but the Solar System’s largest planet and its four bright Galilean moons still provide plenty of observable events during June, as we reveal. If you’re uncertain which evening ‘star’ is Jupiter, the Moon conveniently passes by on the night of 3—4 June, a time when European skywatchers can also see the Moon occult (hide) bright double star Porrima.
Five hundred-metre-wide asteroid 2017 CS passes just 1.9 million miles, or 7.9 lunar distances, from Earth on the afternoon of Monday 29 May 2017. For a few nights around this date, Northern Hemisphere observers with 6-inch and larger ‘scopes can see the asteroid gallop through the constellations of Canes Venatici, Boötes and Hercules at up to 14 degrees/day.
Despite more than seven weeks having passed since opposition, the Solar System’s largest planet Jupiter is still big and bright in the UK evening sky of May, highest in the south around 10pm BST. Find out about the phenomena of Jupiter and its moons that you can see from the British Isles for the remainder of the month, starting with a transit of Jupiter’s Great Red Spot on 19 May.
In the small UK hours of Sunday 14 May, the rising 17-day-old Moon in the southeast lies just 2.4 degrees to the upper-left of Saturn, meaning that the pair will comfortably fit in the same field of view of a typical 10×50 binocular. The ringed planet is now about a month from opposition, so now’s the time to hone your observing skills.
Observers with a clear sky to the south as darkness falls on Sunday 7 May can see the 12-day-old waxing gibbous Moon and planet Jupiter separated by little more than twice the width of a full Moon. For telescope owners in the UK, this is a night where you can also see Jupiter’s Great Red Spot and the planet’s four large Galilean moons.