BEST TIME TO SEE: 15 June, 01:00 BST (00:00 UT) ALTITUDE: 15º LOCATION: Ophiuchus DIRECTION: South FEATURES: Rings, atmospheric banding, occasional white spots, moons EQUIPMENT: 6-inch or larger scope
Saturn reaches opposition on 15 June, a time that finds the planet in the opposite location to the Sun in the sky. This also creates a situation where the distance between Earth and Saturn is minimised for the current period of visibility, bringing the planet to a position where it appears slightly larger and brighter than normal.
Being opposite the Sun in the sky during the month of June isn’t particularly
favourable for mid-northern latitudes because this is the time of year when the Sun is at its highest during the day. Consequently, Saturn is very low in the night sky and from the centre of the UK it barely scrapes an altitude of 15º even when at its highest, due south.
Any changes to the appearance of Saturn at opposition tend to be relatively subtle except, that is, for the rings. These appear to brighten quite noticeably around the opposition date thanks to what’s known as the Seeliger effect. At opposition we get to see the ring particles illuminated head on with their shadows hidden behind each particle’s face. The net effect is that the rings brighten for several days around the opposition date.
At opposition the planet will have a magnitude of 0.0, making it a relatively easy naked-eye object to find as it sits close to the eastern leg of the constellation of Ophiuchus, the Serpent Bearer. If you’re still not sure which object in the sky is Saturn, look due south around 01:00 BST (00:00 UT) on 10 June, where the bright full Moon will be obvious. Saturn will be 2º below the Moon’s southern edge at this time.
BEST TIME TO SEE: 30 June, 22:10 BST (21:10 UT) ALTITUDE: 2º (low) LOCATION: Gemini DIRECTION: Northwest Mercury begins the month as a morning object that barely gets above the east-northeast horizon before sunrise. However, for the first 10 or so mornings it will be relatively bright, and if you have a good flat horizon from the northeast through to the east-northeast you may catch a glimpse of it. On 1 June it shines at mag. –0.3, while on 10 June it will have brightened to mag. –1.0. Superior conjunction occurs on the 21st, after which Mercury reappears in the evening sky. At the end of the month look for it 20-30 minutes after sunset, close to the northwest horizon, where it will be shining at mag. –1.1.
BEST TIME TO SEE: 20 & 21 June, from 04:00 BST (03:00 UT) ALTITUDE: 10º (low) LOCATION: Aries DIRECTION: East Venus is at greatest western elongation on 3 June, when it will appear separated from the Sun by 46º in the morning sky. It should be showing a phase of 50% lit and appear 23 arcseconds across on this date, but visually the half phase may appear a few days later due to the Schröter effect. On the 3rd, the planet is mag. –4.3 and just 1.7º from dim Uranus, but the bright morning twilight will make this a difficult conjunction to see. As the month progresses, Venus’s position improves due to the morning ecliptic forming a steeper angle with the eastern horizon around sunrise. We’ve listed the best time to locate Venus as the mornings around the June solstice because there will be a lovely waning crescent Moon nearby on these dates. Venus appears as an 18-arcsecond diameter, 62%-lit gibbous disc at the end of the month.
BEST TIME TO SEE: 1 June, 22:45 BST (21:45 UT) ALTITUDE: 30º LOCATION: Virgo DIRECTION: South-southwest Jupiter is no longer able to culminate (reach its highest point in the sky due south) in darkness. Instead it appears west of the meridian as darkness falls. A 74%-lit waxing gibbous Moon pays Jupiter a close call on the night of 3 June and into the following morning. Minimum separation occurs around 02:20 BST (01:20 UT) when both objects will appear just 1.4º apart, centre-tocentre. The Moon pays Jupiter a second call on the night of 30 June, but this time the first quarter Moon will appear around 5º away as midnight approaches and they are about to set. Jupiter dims slightly throughout the course of the month, from mag. –2.2 on the 1st to –2.0 by month end. Its apparent size also decreases from 41 arcseconds to 37 arcseconds in this period.
BEST TIME TO SEE: 30 June, 01:22 BST (00:22 UT) ALTITUDE: 9º (low) LOCATION: Aquarius DIRECTION: East-southeast Dim and distant Neptune is slowly crawling away from the Sun and into the morning sky. However, at this time of year true darkness is in short supply and this hinders the visibility of this mag. +7.9 planet. If you do want to try, it can be found low in the east-southeast around 01:20 BST (00:20 UT) at the end of the month. On 30 June it appears 15 arcminutes east of mag. +6.2 star 81 Aquarii. NOT VISIBLE THIS MONTH Mars and Uranus
Saturn, ever the slow mover, remains close to Ophiuchus’s eastern leg in June
A low altitude Saturn above Mars and Antares in 2016 Saturn