Dates and times shown are NZDT (UT + 13 hours). Rise and Set times are for Wellington. They will vary by a few minutes elsewhere in NZ. Data is adapted from that shown by GUIDE 9.1

THE SUN and PLANETS in OCTOBER 2020, Rise & Set  Mag. & Cons.
          OCT 1        NZDT           OCT 30        NZDT  
      Mag  Cons    Rise    Set     Mag  Cons    Rise    Set
SUN  -26.7  Vir   6.52am  7.28pm  -26.7  Lib   6.06am  8.03pm
Merc  -0.0  Vir   7.41am  9.45pm    1.8  Vir   5.41am  6.54pm
Venus -4.1  Leo   5.19am  4.03pm   -4.0  Vir   4.51am  5.05pm
Mars  -2.5  Psc   8.33pm  7.57am   -2.2  Psc   5.56pm  5.30am
Jup   -2.4  Sgr  12.25pm  3.28am   -2.2  Sgr  10.42am  1.41am
Sat    0.5  Sgr   1.03pm  3.53am    0.6  Sgr  11.09pm  1.58am
Uran   5.7  Ari   9.55pm  8.21am    5.7  Ari   7.51pm  6.19am
Nep    7.8  Aqr   5.36pm  6.22am    7.8  Aqr   3.35pm  4.23am
Pluto 14.5  Sgr  12.45pm  3.47am   14.5  Sgr  10.48pm  1.50am

              OCTOBER 1  NZDT          OCTOBER 30  NZDT
Twilights    morning     evening       morning     evening
Civil:    start 6.27am, end 7.55pm   start 5.39am, end 8.31pm
Nautical: start 5.55am, end 8.27pm   start 5.03am, end 9.07pm
Astro:    start 5.21am, end 9.01pm   start 4.24am, end 9.46pm

  Full Moon:     OCT  2 at 10.05am (Oct  1, 21:05 UT)
  Last quarter:  OCT 10 at  1.39pm (00:39 UT)
  New Moon:      OCT 17 at  8.31am (Oct 16, 19:31 UT)
  First quarter: OCT 24 at  2.23am (Oct 23, 13:23 UT)
  Full Moon:     Nov  1 at  3.49am (Oct 31, 14:49 UT)


MERCURY starts the month at its greatest elongation, 26° east of the Sun. As a result it will be well placed (for Mercury) for evening viewing with an altitude 13° an hour after sunset. With a magnitude 0.0 it should be an easy object just south of due west.

After its greatest elongation the planet's motion slows so that its distance from the Sun begins to decrease. But Mercury is still 20° from the Sun when stationary on the 14th. After that the planet starts moving back towards the Sun so that their separation rapidly decreases.

By October 26 the planet is at inferior conjunction between the Sun and Earth, when it is less than a degree from the Sun. For the rest of October the planet becomes a morning object rising before the Sun, but is too close to the Sun to observe.

VENUS is a morning object easily visible to the northeast an hour before sunrise, although rather low. Early in the month it passes close to the 1.4 magnitude star Regulus. On the morning of the 3rd they will be about a quarter degree apart an hour before sunrise. They are closer during daylight hours near midday with a 5 arc-minute separation.

The crescent moon is some 4° from Venus, on the 14th the two being closest about 5 pm NZDT. Their closest approach visible from New Zealand is in the early morning of the 14th when the two are some 7° apart.

MARS is slightly brighter than Jupiter for most of the month. It starts October at magnitude -2.5 with Jupiter at -2.4.

The planet is closest to the Earth on the night of 6/7 October, 62.1 million km, 0.41 AU, from the Earth. It is at opposition a week later. Mars will then be 62.7 million km, 0.42 AU away. Mars's magnitude will be 2.6 on these dates. By the end of October it will be a similar brightness to Jupiter, both at 2.2.

JUPITER and SATURN are well placed in the evening sky during October. They start the month just over 7° apart with Jupiter leading the way across the sky, but closing in on Saturn as the month progresses. By the end of the month they are 2° closer.

The first quarter moon will be just over 2° from Saturn early evening on the 23rd.

PLUTO remains between Jupiter and Saturn during October, now somewhat closer to Jupiter. At magnitude 14.5 it will only be visible in a moderate telescope.

URANUS is in Aries, rising during the evening in October. The moon, less than 3 days after being full, is just under 3° from the planet at about 11pm on October 4, while the two are fairly low. At magnitude 5.7, Uranus is an easy binocular object

NEPTUNE rises before sunset so is well up by the time she sky darkens. Its encounter with the moon is on the 27th, the two are closest at about 10 pm. The moon, three days short of full, will then be about 3.5° from the planet.


                   OCT 1 NZDT          OCT 30 NZDT  
                Mag  Cons  transit    Mag  Cons  transit
(1)  Ceres      8.2   PsA  11.07pm    8.7   Aqr   9.05pm
(4)  Vesta      8.4   Leo  10 16am    8.2   Leo   9.04am
(8)  Flora      8.6   Cet   3.41am    8.0   Cet   1.23am

CERES is in the evening sky. It moves from Piscis Austrinus to Aquarius mid month and is stationary on November 23

VESTA is a morning object rising about 100 minutes before the Sun on the 1st and about 140 minutes before on the 31st. It starts October 7° from Venus but the latter steadily pulls away from the asteroid over subsequent evenings during the month.

FLORA has two close encounters with bright stars in Cetus during October. It starts the month 1.35° from the 2.5 magnitude star Menkar, alpha Ceti. The two are closest, just under 1° apart on the 8th and 9th, when they rise about 9.30 pm. On the 9th, at about 11 pm, Flora will be to the left of Menkar. The two will then be about 17° up to the east-north-east.

On the night of October 30/31, Flora passes very close to the binary star gamma Cet, Kaffaljidhma. The pair of stars have magnitudes 3.5 and 6.1 with a separation 2.5 arc-second. Flora and the star are closest about 3:50am on the 31st, with a separation 3.2 arc-minutes. By then Flora will be near opposition at magnitude 8.0 making it temporarily the brightest asteroid.

Brian Loader