The Solar System in July 2016

Dates and times shown are NZST (UT + 12 hours) unless otherwise stated.

Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

Sunrise, sunset and twilight times in July

                            July  1  NZST                    July 31  NZST
                    morning  evening                 morning  evening
       SUN: rise:   7.44am,  set:  5.04pm    rise:   7.27am,  set:  5.27pm
Twilights
  Civil:    starts: 7.16am,  ends: 5.33pm    starts: 7.00am,  ends: 5.55pm
  Nautical: starts: 6.42am,  ends: 6.08pm    starts: 6.27am,  ends: 6.28pm
  Astro:    starts: 6.08am,  ends: 6.41pm    starts: 5.54am,  ends: 7.01pm

July phases of the Moon (times as shown by GUIDE)

          New moon:      July  4 at 11.01 pm (11:01 UT)
  First quarter: July 12 at 12.52 pm (00:52 UT)
  Full moon:     July 20 at 10.57 am (July 19, 22:57 UT)
  Last quarter   July 27 at 11.00 am (July 26, 23:00 UT)

The planets in July

All five naked eye planets are visible during some part of the evening by late July. Mercury becomes easily visible in the early evening sky towards the end of the month. Venus will be lower Mercury from the second part of July. Mars remains prominent although fading a little while Jupiter gets lower to the east. Saturn will not be far from Mars.

Mercury is at superior conjunction on July 7, when it will be 47 million km (0.314 AU) beyond the Sun and 199 million km (1.33 AU) from the Earth. Before conjunction Mercury will be too close to the Sun to observe, after conjunction it becomes an evening object setting after the Sun. By the end of July the planet will set nearly 2 hours later than the Sun. On the evenings of the 30th and 31st Mercury will be less than a degree from Regulus with Mercury at magnitude -0.1, 1.5 magnitudes brighter than Regulus. About an hour after sunset the two will be 7° up in a direction half way between west and northwest.

Earlier in July on the 16th, Mercury and Venus will be less than a degree apart. But the two planets will set only 45 minutes after the Sun, making observation difficult. At 5.30 with the Sun only 4° below the horizon, the planets will be a low 4° above it. Venus at magnitude -3.9 May be detectable, Mercury's magnitude being-1.1.

Venus, in the very early evening sky will set less than half an hour after the Sun on the 1st and about 50 minutes after the Sun on the 31st. So it will be a very low object at best.

Venus starts the month in Gemini, moves across Cancer between July 10 and 26 and ends the month in Leo heading towards Regulus.

Mars remains a prominent evening object although loses a little of its brightness during July as the Earth recedes from it. By the end of the month it will still be bright at magnitude -0.8.

The planet will be in Libra moving rather slowly to the east after being stationary at the end of June. By the end of July, Mars will be poised to cross into Scorpius, heading towards its rival Antares.

The moon passes Mars mid month, but the two do not get very close. They are about 10° apart on the nights of July 14 and 15.

Jupiter becomes an early evening object during July, setting just after 9pm on the 31st. It remains in Leo.

The 25% lit crescent moon will be just over 1° from Jupiter on July 9. An occultation of the planet is only visible from the Southern Ocean to the south of Australia and parts of Antarctica beyond.

Saturn is well paced for evening viewing during July, a bright object about 6° from Antares which it will outshine by nearly a magnitude. The colour of the two makes a contrast. The planet is in Ophiuchus moving slowly in a retrograde sense to the west.

The 87% lit moon will be just under 4° from Saturn on the evening of July 16.

Outer planets

Uranus, at magnitude 5.9, is a morning object in Pisces although it will rise just before midnight by the end of July. It is stationary on the 30th , with its position changing only slightly during the month.

Neptune rises near 10 pm at the beginning of the month advancing to 8am by the month's end. The planet, at magnitude 7.9, is in Aquarius and will be about half a degree from the 3.7 magnitude star lambda Aqr. In the mid to late evening Neptune will be to the right of the star early in the month gradually moving up to be at the star's upper right by the end of the month. There are no stars as bright as Neptune between them to cause confusion.

Pluto at magnitude 14.3 is also in evening sky during July. The planet remains in Sagittarius. It moves away from the 2.9 magnitude star pi Sgr during July, starting only 8 arc-minutes from the star on the 1st, the distance increasing to almost a degree by the 31st.

Minor planets

(1) Ceres, is in Cetus during July moving to the east. It brightens slightly through the month, from 9.2 to 8.9.. It rises at 1.30 am on the 1st and close to midnight on the 31st.

(4) Vesta rises 100 minutes before the Sun on July 1 and just after 5 am on the 31st. Starting the month in Taurus, Vesta will be less than half a degree from the magnitude 3 star zeta Tau on the morning of the 14th. On the 21st the asteroid will cross into Orion.

Brian Loader  
New Zealand

The Solar System in June 2016

Dates and times shown are NZST (UT + 12 hours) unless otherwise stated.

Rise and set times are for Wellington. They will vary by a few minutes elsewhere in NZ.

The southern hemisphere winter solstice is on June 21 with the Sun furthest north at about 10am.

Sunrise, Sunset and Twilight Times in June

                            June  1  NZST                    June 30  NZST
                    morning  evening                 morning  evening
       SUN: rise:   7.34am,  set:  5.02pm    rise:   7.45am,  set:  5.04pm
Twilights
  Civil:    starts: 7.06am,  ends: 5.31pm    starts: 7.16am,  ends: 5.33pm
  Nautical: starts: 6.32am,  ends: 6.05pm    starts: 6.42am,  ends: 6.07pm
  Astro:    starts: 5.58am,  ends: 6.39pm    starts: 6.08am,  ends: 6.41pm

June Phases of the Moon (Times as Shown By Guide)

          New moon:      June  5 at  3.00 pm (03:00 UT)
  First quarter: June 12 at  8.10 pm (08:12 UT)
  Full moon:     June 20 at 11.02 pm (11:02 UT)
  Last quarter   June 28 at  6.19 am (June 27, 18:19 UT)

The Planets in June

Mars, Saturn and Jupiter will be prominent in the evening sky with the latter low by late evening. Mercury will start June as an easy morning object in the dawn sky. It will brighten during the month but get too close to the Sun to observe towards the end of June.

Venus is at superior conjunction on June 7, it then becomes an evening object but remains too close to the Sun to observe.

Mercury starts June as a morning object rising more than 2 hours before the Sun on the 1st. With a magnitude 0.9 it will be 10° up an hour before sunrise. Look for Mercury in a direction nearly 30° north of east. The planet is at its greatest elongation 24° west of the Sun on the 5th. During the rest of June Mercury will slip back towards the Sun but also gain in brightness, reaching a magnitude -1.6 on the 30th. But by then it will rise only 30 minutes before the Sun.

On the morning of June 4 a very thin crescent moon will be 6° from Mercury, the moon to the lower right of the planet. An occultation of Mercury by the moon, shortly before midnight NZ time, will only be visible from parts of the southern Atlantic Ocean including South Georgia.

Venus is close to the Sun all month. Too close for observation. On the first it rises into the morning sky only 7 minutes before the Sun.

The planet is at superior conjunction on the far side of the Sun on June 7. At this conjunction Venus will pass behind the Sun as "seen" from the Earth. In fact the "occultation" of Venus by the Sun lasts from about 11 am on June 6 (June 5, 23hr UT) to 9am on June 8 (June 7, 21 hr UT), that is for some 46 hours. At conjunction Venus will be 108 million km (0.72 au) beyond the Sun

After conjunction Venus will become an evening object. By the end of June it will set only 25 minutes after the Sun.

Mars starts June at magnitude -2.0, the same as Jupiter. But the colours are very different, Mars being distinctly orange. Following conjunction late in May, the Earth will be pulling away from Mars during June. As a result the planet will dim a little, but still be at magnitude -1.6 on the 30th.

During June Mars will be in Libra moving to the west towards alpha Lib and away from Antares and Saturn. The planet is stationary on June 30.

The 90% lit moon will be at its closest to Mars for the month on the evening of the 17th when the two will be a little over 8° apart..

Jupiter will be best placed for viewing early evening as it sets shortly after midnight on the 1st and at 10.42 pm on the 30th. The planet remains in Leo, its position changes little during the month, being stationary on June 10.

The 41% lit moon will be about 5° below Jupiter an hour or so before they set on June 11. They will be considerably closer, while below NZ's horizon, a few hours later.

Saturn is at opposition on June 3, so will be rising close to the time of sunset and setting near the time the Sun rises. At opposition Saturn will be 1.35 billion km from the Earth (9.01 AU) and a further 150 million km from the Sun.

The planet is in Ophiuchus moving slowly to the west a few degrees below Antares, as seen in the evening. With a zero magnitude Saturn is noticeably brighter than Anatares or any other star near it. Mars, brighter still, is 18° from Saturn.

The moon passes Saturn on the 19th but the two will be closest soon after midday. By the time they are visible in the evening the almost full moon will be 5° below Saturn. The latter will be about 22° up to the east.

Outer Planets

Uranus is a morning object in Pisces at magnitude 5.9. It rises about 4 hours before the Sun on June 1 and 6 hours earlier on the 30th. The moon passes Uranus twice during June.

On the morning of June 2 at about 7am, the 15% lit crescent moon will be just over 3° from Uranus. The planet will be to the left of the moon and a little higher. It should be easy to spot Uranus using binoculars, there are two stars a little fainter than Uranus between the two.

The moon passes Uranus again on the 29th. This time the two are closest at midday, at 7am they will again be just over 3° apart, with the 38% lit moon above and a little to the left of Uranus..

Neptune rises at midnight on June 1 and nearly 2 hours earlier on the 30th. So the planet is beginning to move into the evening sky, but will still be best placed for viewing in the morning a while before sunrise. The planet, at magnitude 7.9, is in Aquarius.

Neptune is stationary on June 14 after which it will start to move slowly to the west. It will be about half a degree from the 3.7 magnitude star lambda Aqr. The planet will be to the upper right of the star. No stars as bright as Neptune are between the two.

Pluto at magnitude 14.3 rises early evening during June, less than half an hour after sunset by the end of the month. The planet remains in Sagittarius. It passes the 2.9 magnitude star pi Sgr during June, with the two only 3 arc-minutes apart, one-tenth the diameter of the full moon, on the 25th.

Minor Planets

(1) Ceres, magnitude 9.3, is in Cetus during June. It rises at 2.45 am on the 1st and just under an hour earlier by the 31st.

(4) Vesta is a dawn object in Taurus. At the beginning of June it rises half an hour before the Sun, by the end of the month some 95 minutes before the Sun. Mercury passes Vesta during June as the two move east. They are closest on the mornings of June 22 and 23 when Vesta (magnitude 8.4) will be 2° to the upper right of Mercury (magnitude -0.8)

Brian Loader
New Zealand