Mercury remains an early morning object from southern and tropical regions during the first half of the month. From such locations, the planet can be glimpsed low down above the east-northeastern horizon just before sunrise. However, it's not long before it's lost to the bright twilight sky and by the second week of the month it will be difficult to spot. Mercury then heads towards superior conjunction, which it reaches on June 21st.
From northern temperate latitudes, the planet is unsuitably placed for observation throughout June.
The current morning apparition of Venus peaks on June 3rd when it reaches greatest elongation west. On this day the planet will be positioned 46 degrees from the Sun. From southern locations, it rises nearly over 3.5 hours before sunrise although for only about half this time from mid-latitude northern locations. The brilliant planet shines at mag. -4.4 and is therefore an unmistakable beacon of light that hovers above the eastern horizon. It remains well placed in the morning sky for the remainder of the month.
On June 2nd, Venus passes 2 degrees south of Uranus and observers with binoculars and wide-field telescopes should be able to spot both planets in the same field of view. The magnitude contrast is extreme with Venus over 10,000 times brighter than Uranus (mag. +5.9).
On June 12th, Venus reaches aphelion when it's 0.728 AU (approx. 109 million kilometres or 67.7 million miles) distant from the Sun. Later on June 20th, the thin waning crescent Moon passes 2 degrees south of the planet, providing pleasant viewing for early risers.
Mars is unsuitably placed for observation this month as it heads towards solar conjunction in July.
Jupiter remains a brilliant evening object. The gas giant is unmistakable in the constellation of Virgo and is visible as soon as darkness falls. By months end it sets about an hour after midnight.
The largest planet in the Solar System begins the month moving slowly retrograde. On June 10th, it reaches its second stationary point and after that direct motion is resumed. This event is widely regarded as signalling the end of the current opposition period. To the unaided eye, Jupiter will hardly appear to move this month, relative to the background stars.
On June 1st, the planet shines at mag. -2.3 and has an apparent diameter of 41 arc seconds. At the end of the month, it dims down to mag. -2.1 with an apparent diameter of 37 arc seconds.
Saturn, mag. 0.0, reaches opposition in Ophiuchus on June 15th. This month, the sixth planet from the Sun is at its best for the year and practically visible all night long. With a declination of -22 degrees, Saturn is much better placed from southern and tropical locations, where it appears higher in the sky and has a longer visibility period than from northern temperate latitudes.
At opposition, Saturn is 9.043 AU (1,353 million kilometres or 841 million miles) from Earth. Even a small telescope will show its most famous feature, the spectacular ring system. Also visible is Titan, the largest and brightest moon, which at 8th magnitude can be seen with binoculars. Small scopes reveal other moons including Rhea, Tethys and Dione. Saturn's disk spans 18.4 arc seconds in diameter.
On June 10th, the almost full Moon passes 3 degrees north of Saturn.
Uranus, mag. +5.9, is now a morning object in Pisces. For northern temperate observers, the planet remains low down during the early part of the month but by months end rises three hours before the Sun. Observers located further south have it even better with Uranus well placed throughout the month. On June 30th, from such locations it rises a couple of hours after midnight.
As previously mentioned, Venus will pass 2 degrees south of Uranus on June 2nd. The waning crescent Moon passes 4 degrees south of Uranus on June 19th.
Neptune, mag. +7.9, is now well placed for observation in Aquarius. By months end the distant planet rises around midnight from northern temperate latitudes, but much earlier for those located further south.
Neptune is located 30 degrees south and slightly west of the centre of the Great Square of Pegasus. Lambda Aqr (λ Aqr - mag. +3.7) is positioned 2.5 degrees west-southwest of the planet. Neptune is the only planet that's not visible to the naked eye, but it can be easily seen with binoculars and small telescopes.
On June 16th, Neptune reaches its first stationary point, which signals the beginning of this year's opposition period. The planet then commences retrograde motion. On the same evening, the waning gibbous Moon passes less than a degree to the south.
Solar System Data Table June 2017
|Date||Right Ascension||Declination||Apparent Magnitude||Apparent Size||Illum. (%)||Distance from Earth (AU)||Constellation|
|Sun||5th Jun 2017||04h 51m 52.6s||22d 30m 49.4s||-26.7||31.5'||100||1.015||Taurus|
|Sun||15th Jun 2017||05h 33m 15.2s||23d 17m 40.3s||-26.7||31.5'||100||1.016||Taurus|
|Sun||25th Jun 2017||06h 14m 50.9s||23d 23m 34.6s||-26.7||31.5'||100||1.016||Gemini|
|Mercury||5th Jun 2017||03h 37m 39.0s||17d 36m 05.5s||-0.6||05.9"||74||1.140||Taurus|
|Mercury||15th Jun 2017||04h 58m 26.7s||22d 42m 11.5s||-1.5||05.2"||95||1.286||Taurus|
|Mercury||25th Jun 2017||06h 33m 23.4s||24d 42m 42.6s||-1.9||05.1"||98||1.320||Gemini|
|Venus||5th Jun 2017||01h 49m 14.5s||08d 45m 09.7s||-4.4||23.4"||50||0.712||Pisces|
|Venus||15th Jun 2017||02h 27m 51.8s||11d 49m 04.3s||-4.3||21.1"||55||0.793||Aries|
|Venus||25th Jun 2017||03h 09m 01.2s||14d 49m 51.7s||-4.2||19.1"||60||0.872||Aries|
|Mars||5th Jun 2017||05h 59m 54.5s||24d 19m 46.0s||+1.7||03.7"||99||2.546||Taurus|
|Mars||15th Jun 2017||06h 28m 57.5s||24d 12m 56.9s||+1.7||03.6"||100||2.578||Gemini|
|Mars||25th Jun 2017||06h 57m 40.8s||23d 46m 13.7s||+1.7||03.6"||100||2.606||Gemini|
|Jupiter||5th Jun 2017||12h 50m 04.3s||-03d 49m 32.9s||-2.2||40.3"||99||4.893||Virgo|
|Jupiter||15th Jun 2017||12h 50m 02.9s||-03d 52m 16.4s||-2.2||39.2"||99||5.035||Virgo|
|Jupiter||25th Jun 2017||12h 51m 07.0s||-04d 01m 52.7s||-2.1||38.0"||99||5.185||Virgo|
|Saturn||5th Jun 2017||17h 38m 31.7s||-21d 58m 50.0s||+0.1||18.3"||100||9.059||Ophiuchus|
|Saturn||15th Jun 2017||17h 35m 22.6s||-21d 57m 41.2s||0.0||18.4"||100||9.043||Ophiuchus|
|Saturn||25th Jun 2017||17h 32m 13.0s||-21d 56m 33.9s||0.0||18.4"||100||9.056||Ophiuchus|
|Uranus||5th Jun 2017||01h 40m 48.3s||09d 51m 12.3s||+5.9||03.4"||100||20.598||Pisces|
|Uranus||15th Jun 2017||01h 42m 19.2s||09d 59m 39.3s||+5.9||03.4"||100||20.466||Pisces|
|Uranus||25th Jun 2017||01h 43m 36.2s||10d 06m 43.7s||+5.9||03.5"||100||20.319||Pisces|
|Neptune||5th Jun 2017||23h 02m 22.9s||-07d 07m 25.0s||+7.9||02.3"||100||29.926||Aquarius|
|Neptune||15th Jun 2017||23h 02m 31.1s||-07d 07m 00.1s||+7.9||02.3"||100||29.758||Aquarius|
|Neptune||25th Jun 2017||23h 02m 27.2s||-07d 07m 50.1s||+7.9||02.3"||100||29.595||Aquarius|