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 is adapted from that shown by GUIDE 9.

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

      May  1         NZST          May 31         NZST  
      Mag  Cons    Rise    Set     Mag  Cons    Rise    Set
SUN  -26.7  Ari   7.05am  5.30pm  -26.7  Tau   7.33am  5.03pm
Merc   0.3  Psc   4.45am  4.34pm   -1.6  Tau   7.03am  4.40pm
Venus -3.9  Tau   9.26am  6.49pm   -3.9  Gem  10.15am  7.19pm
Mars  -0.4  Sgr   9.54pm 12.57pm   -1.2  Cap   8.50pm 11.45am
Jup   -2.5  Lib   5.48pm  7.56am   -2.5  Lib   3.39pm  5.39am
Sat    0.3  Sgr   8.52pm 11.50am    0.2  Sgr   6.48pm  9.47am
Uran   5.9  Ari   6.04am  4.57pm    5.9  Ari   4.14am  3.03pm
Nep    7.9  Aqr   2.24am  3.18pm    7.9  Aqr  12.29am  1.21pm
Pluto 14.4  Sgr   9.48pm 12.40pm   14.4  Sgr   7.48pm 10.41am

              May  1  NZST              May 31  NZST
Twilights    morning     evening        morning     evening
Civil:    start 6.39am, end 5.57pm   start 7.05am, end 5.32pm
Nautical: start 6.06am, end 6.29pm   start 6.31am, end 6.06pm
Astro:    start 5.34am, end 7.02pm   start 5.58am, end 6.39pm


  Last quarter   May  8 at  2.09pm (02:09 UT)
  New moon:      May 15 at 11.48pm (11:48 UT)
  First quarter: May 22 at  3.49pm (03:49 UT)
  Full Moon:     May 30 at  2.20am (May 29, 14:20 UT)

MERCURY starts May relatively well placed for morning observation, rising well over 2 hours before the Sun. On the 1st, just after 6am and an hour before sunrise, it will be 14° above the horizon and 27° from the Sun. At magnitude 0.3 the planet should be easily visible a little to the north of east.

During May the planet closes in on the Sun on a path which takes it past Uranus mid month. On the morning of the 14th Mercury, now magnitude -0.2, will be between a very thin crescent moon to its right and Uranus to its left. They should make an interesting binocular grouping 10° up an hour before sunrise.

VENUS, an evening object, starts May in Taurus some 6° below Aldebaran. At 6pm the planet will be low, only 6° up to the northwest. During the rest of May Venus makes its way across Taurus to pass between beta and zeta Tau, magnitudes 1.7 and 2.9, on the 14th.

By the end of May, Venus will be more readily visible, about 13° up half an hour after sunset.

MARS rises late to mid evening and sets near noon the following day so being in New Zealand skies for some 15 hours. At the beginning of May it is some 15° from Saturn their separation nearly doubling during the month. The planet brightens noticeably during May

The moon passes Mars on the evening of the 6th. By the time both have risen for New Zealand, near midnight, they will be 4.5° apart

JUPITER is at opposition on May 9 with a magnitude -2.5. It will then rise close to the time of sunset and set close to the time of sunrise, making it visible all night. At opposition Jupiter will be 4.400 AU, 658 million km, from the Earth and 5.4 AU from the Sun.

The moon, two days short of full, will be about 4.5° from Jupiter on the morning of the 28th. For New Zealand the two are closest at the time they set.

SATURN, in Sagittarius, moves slowly to the west in a retrograde sense during May, as the faster moving Earth begins to overtake it. By the end of the month Saturn will rise early evening, so making it readily visible by mid to late evening.

URANUS moves further up into the morning sky during May. On the morning of the 14th it will be just over 2° to the left of Mercury which itself will be 2° to the left of the crescent moon. A star, of similar magnitude to Uranus will be about 11’ to its left. All should be in the field of binoculars, best seen about an hour before sunrise, although they will be low.

NEPTUNE is a morning object during May, rising shortly after midnight by the end of the month. The moon will be some 4° from Neptune on the morning of the 10th.

PLUTO, in Sagittarius, starts May just under 3° from Mars. The latter moves steadily away from Pluto during the rest of the month.

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

                MAY 1                MAY 31   
            Mag  Cons   transit    Mag  Cons   transit
(1) Ceres   8.4   Cnc    6.50pm    8.7   Leo    5.28pm
(2) Pallas  9.1   Ori    3.03pm    9.1   Ori    2.08pm
(4) Vesta   6.5   Sgr    4.02am    5.8   Sgr    1.56am

(1) CERES, in Cancer, is an evening object setting just after 11 pm on the 1st. The asteroid crosses into Leo on the 17th heading towards the star epsilon, magnitude 3.0. The two are 1.3° apart on the 31st when Ceres sets at 10pm.

(2) PALLAS is an early evening object, setting at 9.17 pm on the 1st. It is in Orion during May, passing between the stars epsilon, mag 1.7 and zeta, mag 1.9 on the 12th. Pallas sets at 8.11 pm on the 31st.

(4) VESTA is a few degrees from Saturn and, like the ringed planet, is moving in a retrograde sense. On the night of the 4th and 5th the moon will pass between the asteroid and planet. The three are in line about 4.30 am with the moon almost midway between the two. Vesta will be at magnitude 6.5. The moon is again close to Vesta on the 31st. At 10.30 pm the moon will be just over 2° above the planet.

Brian Loader