THE SOLAR SYSTEM IN APRIL 2018

Dates and times shown are NZST (UT + 12 hours) unless otherwise stated. Times are for Wellington. They will vary by a few minutes elsewhere in NZ. Data adapted from that shown by GUIDE 9.
NZDT ends at 3 am on April 1 when. All local times are given in NZST

THE SUN and PLANETS in APRIL 2018, Rise & Set, Mag. & Cons.

      April  1         NZST          April 30    NZST  
      Mag  Cons    Rise    Set     Mag  Cons    Rise    Set   
SUN  -26.7  Psc   6.33am  6.15pm  -26.7  Ari   7.04am  5.31pm
Merc   5.9  Psc   6.48am  6.01pm    0.3  Cet   4.44am  4.35pm
Venus -3.9  Ari   8.14am  7.04pm   -3.9  Tau   9.24am  6.49pm
Mars   0.3  Sgr  10.41pm  1.53pm   -0.4  Sgr   9.56pm 12.59pm
Jup   -2.4  Lib   7.54pm 10.09am   -2.5  Lib   5.52pm  8.00am
Sat    0.5  Sgr  10.50pm  1.48pm    0.4  Sgr   8.56pm 11.54am
Uran   5.9  Psc   7.57am  6.54pm    5.9  Ari   6.08am  5.01pm
Nep    8.0  Aqr   4.17am  5.14pm    7.9  Aqr   2.28am  3.22pm
Pluto 14.5  Sgr  11.46pm  2.37pm   14.4  Sgr   9.52pm 12.43pm

              April  1  NZST              April 30  NZST
Twilights    morning     evening        morning     evening
Civil:    start 6.08am, end 6.41pm   start 6.38am, end 5.58pm
Nautical: start 5.36am, end 7.13pm   start 6.05am, end 6.31pm
Astro:    start 5.04am, end 7.45pm   start 5.33am, end 7.03pm

APRIL PHASES OF THE MOON, times NZDT (& UT)

  Full moon:     April  1 at 12.37am (Mar 31, 12:37 UT)
  Last quarter   April  8 at  7.18pm (07:18 UT)
  New moon:      April 16 at  1.57pm (01:57 UT)
  First quarter: April 23 at  9.46am (Apr 22, 21:46 UT)
  Full Moon:     April 30 at 12.58pm (00:58 UT)

Strictly the full moon of April 1 occurs before the end of NZDT, at 1.37 am.

MERCURY is at inferior conjunction on April 2 at ca 5am. It will then be nearly 3° north of the Sun as "seen" from the Earth. The planet will be just over 89 million km, 0.60 AU from the Earth and 0.40 AU from the Sun. After conjunction Mercury becomes a morning object. At its best, towards the end of April, it rises 140 minutes before the Sun. At 6am, an hour before sunrise, Mercury will be some 13° above the horizon in a direction 15° to the north of east. This will be the best morning apparition of Mercury in 2018 for southern hemisphere viewers.

VENUS, is a low evening object briefly visible soon after sunset, best positioned at the end of April. It moves from Aries into Taurus on April 20 and is 3° above the Pleiades on the 25th. While Venus may be visible some 7° up at about 6 pm, the Pleiades may be too faint to see.

MARS, is well south of the equator, rising late evening and not setting until early the following afternoon. It starts the month close to Saturn, the two being 1.3° apart on the 3rd. Over the next few days Mars rapidly draws away from Saturn. The moon, a few hours short of last quarter passé the two planets on the morning of the 7th. On the night of April 26/27 Mars will be just over 1.4° from Pluto.

JUPITER will be visible much of the evening, by the end of the month rising only 20 minutes after the Sun sets. It will be moving in a retrograde sense, towards the west. The moon passes Jupiter early in April, the two being closest, 4° apart on the morning of the 4th.

SATURN, in Sagittarius, is stationary on April 18. It then begins to move in a retrograde sense, almost retracing its path, to end the month close to where it started. See also under Mars.

URANUS is at conjunction on April 18 so is virtually unobservable all month. At conjunction it will be just under 20 AU beyond the Sun and one more from the Earth, at 3126 million kilometres. After conjunction Uranus starts to move into the morning sky.

NEPTUNE moves further up into the morning sky, to rise more than 4.5 hours before the Sun by the end of April. The crescent moon is at its closest to Neptune on the morning of April 13 when it will be 2.5° above the planet as seen an hour before sunrise.

PLUTO, in Sagittarius is stationary on April 23 when it begins to move in a retrograde sense. By the end of the month it will rise late evening and be close to Mars.

BRIGHTEST ASTEROIDS in APRIL, magnitude, constellation, time of transit

                APRIL 1                APRIL 30   
            Mag  Cons   transit    Mag  Cons   transit
(1) Ceres   8.0   Cnc    8.27pm    8.4   Cnc    6.53pm
(2) Pallas  9.1   Eri    4.03pm    9.1   Ori    3.05pm
(4) Vesta   7.1   Sgr    5.40am    6.5   Sgr    4.06am

(1) CERES, in Cancer, is an evening object setting shortly after midnight on the 1st and at 11:08 pm on April 30th.

(2) PALLAS is an early evening object, setting at 9.20 pm by the end of April.

(4) VESTA is moving into the evening sky during April, rising at 10.31 on the 1st and just before 9 pm on the 30th when it will be 6.6° from Saturn. The moon will be just over 3° from Vesta an hour before sunrise on April 7.

 

Brian Loader