April Moon & Planet data for 2013


Phases of the moon (times as shown by guide)

  Last quarter:  Apr  3 at  5.37 pm NZDT (04:37 UT)
  New moon:      Apr 10 at  9.35 pm NZST (09:35 UT)
  First quarter: Apr 19 at 12.31 am NZST (Apr 18, 12:31 UT)
  Full moon:     Apr 26 at  7.57 am NZST (Apr 25, 19:57 UT).

The planets in April

Only Jupiter and Saturn will be readily visible during February. By the end of the month Jupiter will set about midnight so will be low late evening. Saturn will still be best seen as a morning object, but will rise a little 11 pm at the end of the month.

Mercury and Mars will be very low in the sky immediately after sunset, while Venus will be low in the morning sky at sunrise.

Comet Panstarrs may be reasonably bright by the end of February, visible both in the morning and evening, rising before the Sun and setting after it.

The evening sky.

VENUS was at superior conjunction at the end of March. In April it is an evening object, but will set less than half an hour after the Sun so will be at best very difficult to see.

MARS is at conjunction with the Sun on April 18, so will also not be visible during April. After conjunction it will become a morning sky object.

JUPITER sets just over 2.5 hours after the Sun at the beginning of April and about 1.5 hours after it at the end of the month. 30 minutes after sunset it will be visible to the northwest, about 21° up on the 1st, reducing to 15° by the 30th. The planet remains in Taurus with Aldebaran to its left, their separation increasing from a little over 5° on the 1st to 9° during April.

The crescent moon passes Jupiter on the morning of the 15th. They are closest about 6 am while Jupiter is set in NZ. The previous evening the two will be about 6.5° apart with the moon left of Jupiter. The following evening they will be about a degree closer, but with the moon now to the right of Jupiter.

SATURN is at opposition on April 28 and becomes a good evening object during the month. On the 1st it will rise a little after 8.30 pm, NZDT. By the end of April it will rise a few minutes after 5.30 pm NZST. Two hours after it rises, the planet will be a little over 20° up to the east

Saturn is in Libra all April with the wide double star alpha Lib a few degrees to its right. Alpha Lib has a magnitude 2.7, its companion 5.2. Beta Lib will be about twice as far away to the lower right of the planet. Despite its name, beta is slightly brighter than alpha. The star Spica, will be another step further away to the upper left of Saturn. At magnitude 1.1 Spica is the brightest of the three star, but Saturn is a magnitude brighter still.

The moon, a few hours past full, will be some 5° to the right of Saturn in the early evening of April 26. During the evening the moon will slowly move further from Saturn towards the star alpha Lib. The moon will occult the star soon after 10.30 pm as seen in New Zealand, times varying by a few minutes through the country. This disappearance takes place on the lit limb of the moon making it very difficult to observe. Just over an hour later the star emerges again from the opposite side of the moon.

The morning sky: Mercury (and Saturn)

MERCURY, in the morning sky, rises more than 2 hours before the Sun during the first half of April. An hour before sunrise it will be an easy object to the east about 15° above the horizon.

It starts the month at magnitude 0.3 and brightens to -0.1 by the 15th and -0.9 by the 30th. This makes it the brightest star-like object in the eastern sky.

During the second half of April the planet will become lower in the morning sky, by the 30th it rises only 70 minutes before the Sun The lower altitude will be compensate by its increasing brightness so it should be visible 45 minutes before sunrise.

On the morning of the 21st Mercury will be 2° to the right of Uranus. At magnitude 5.9 Uranus is readily visible through binoculars as the brightest object to the right of Mercury. A star, half a magnitude fainter than Uranus will be quite close to its lower. This should present a good opportunity to view the outer planet.

SATURN in the morning sky becomes very low to the west before sunrise so will only be readily visible well before that time.

Outer planets

URANUS moves up into the morning sky. Its conjunction with Mercury on the 21st is note above.

NEPTUNE is a 7.9 magnitude, morning object in Aquarius, some 30° above and to the left of Mercury. The 14% lit crescent moon will be 6° to the left of Neptune on the morning of April 7.

Brighter asteroids:

Both (1) Ceres and (4) Vesta move away from Jupiter and Aldebaran during April.

Ceres spends the month in Auriga with a magnitude near 8.7. Vesta is in Taurus most of the month but moves into Gemini on the 26th. Its magnitude is near 8.3


Diary of events in May

The follwing table lists various solar system object events during April. A list of astronomical terms used in may be found after the table.

April 1 Moon southern most declination (-20.3 degrees)
April 3 Pluto 0.9 degrees south of the Moon Occn
Moon last quarter
April 6 Neptune 5.6 degrees south of the Moon
April 7 Venus 0.6 degrees south of Mars
April 9 Uranus 3.8 degrees south of the Moon
April 10 Moon new
Mars 2.6 degrees south of the Moon
Venus 3.1 degrees south of the Moon
April 12 Pluto stationary
April 14 Aldebaran 3.5 degrees south of the Moon
Jupiter 2.0 degrees north of the Moon
April 15 Moon northern most declination (20.2 degrees)
Moon at apogee
April 18 Mars at conjunction
Moon first quarter
April 20 Mercury 1.8 degrees south of Uranus
April 21 Regulus 5.6 degrees north of the Moon
April 25 Spica 0.1 degrees south of the Moon Occn
Moon full Eclipse
April 26 Saturn 3.4 degrees north of the Moon
April 27 Moon at perigee
April 28 Saturn at opposition
Moon southern most declination (-20.2 degrees)
April 30 Pluto 1.0 degrees south of the Moon Occn
  • apogee: Furtherest point in the orbit of a body orbiting the Earth
  • conjunction: Two astronomical objects are 'lined up' (have the same right ascension) when viewed from Earth
  • declination: 'Latitude' for celestial objects. The distance in degress above (north) or below (south) the celestial equator.
  • perigee: Nearest point in the orbit of a body orbiting the Earth