MERCURY rises more than two hours before the sun at the beginning of May making it a fairly easy object in the early dawn sky. 45 minutes before sunrise the planet will be some 15° above the horizon in a direction about half way round from east to northeast.

On the morning of May 1, Mercury will be 3.5° to the lower right of Venus and 8° to the right of a thin crescent moon making its location quite easy. At magnitude 0.9, Mercury will be brighter than any nearby star, although Venus will of course be much brighter, as will Jupiter 7° below it. Early in May, Mercury will be at its greatest elongation from the Sun, reaching 27° east of the Sun on May 8.

During the first 10 days of May, Venus will move down towards Mercury. On the 7th the two planets will be level, Sky chart for May 7 by the 11th Venus will be closer, only 1.5° to the lower left of Mercury. Jupiter will have moved up to be just below the two. The following morning the three planets will be almost in line, with Jupiter half a degree to the left of Venus. Sky chart for May 12

During the next week or so Mercury and Venus will move down the sky together keeping about the same distance apart. Mercury will also get a little brighter. At first Mercury will be slightly higher than Venus, but as it begins to move back to the sun faster, it will catch up with Venus until the two are again at the same level on May 20. By then the two will be only a couple of degrees above Mars.

Two mornings later, on the 22nd, Mercury will be 2° to the right of Mars with the two 2.5° apart the next morning. Sky charts for May 22 and 24 For the rest of May, Mercury will draw further ahead of Venus as it heads back toward the Sun. By the 31st, Mercury will be 6° below Venus, less than 5° up 45 minutes before sunrise, but also have brightened to magnitude -0.9.

VENUS will rise about 2 and a half hours before the sun at the beginning of May but a little under 2 hours earlier at the end of the month. So it will remain an easy object in the dawn sky although getting noticeably lower. It will pass close to three other planets during May.

Venus starts May a little above Mercury but the two planets are level by the morning of May 7. Sky chart for May 7. After that the two move through the stars as a close pair with Venus slightly lower until May 20 when they are again at the same level. After this Mercury drops below Venus and with the distance between them increasing more rapidly.

Venus, accompanied by Mercury, will pass Jupiter on the 12th when the two brightest planets will be 35' apart, just a little more than the diameter of the full moon. They will make a brilliant pair. Naturally the two are close for a morning or two either side of this date, so even if it's cloudy on the 12th, there should be a chance of seeing the pair some time close. Sky chart for May 12.

The conjunction of Venus and Mars occurs on May 23. As seen from New Zealand, the two will be 1° apart on the morning of the 23rd and 24th. Mars will be a lot fainter than Venus and to its left. Sky charts for May 22 and 24

Not to be outdone, the moon will pass Venus twice in May. On the first morning of the month the moon will be 7° to the lower left of Venus, a very thin crescent only 5.5% lit. Then on the last day of the month, the moon will be 5.5° to the left of Venus, with the moon an even finer crescent only 4% lit.

During May, Venus will be moving away from the Earth as it journeys round the sun. At the beginning of the month it will be 214 million km from us, by the end of May 235 million km. As a result it will appear to get a little smaller and its apparent distance from the sun will decrease. But the fraction lit will increase from 88% to 93% resulting in little change in brightness.

MARS, with Jupiter, joins in the conjunctions right at the beginning of May. On the morning of the 1st the two planets will be only 24' apart, less than the diameter of the full moon. Jupiter will, of course, be far brighter than Mars. Sky chart for May 1

It will be 3 weeks later when Mercury and Venus are in conjunction with Mars. Mercury is closest to Mars on the morning of the 22nd, when the planets will be just over 2° apart. Venus will be above the pair, only 1.2° from Mars. Two morning later Venus and Mars will be at their closest, just over 1° apart and almost level. Mars at magnitude 1.3 will have only 1% of the brightness of Venus, but will still be brighter than any nearby star (but not as bright as Mercury about 2.5° away to the lower right of the pair). Sky charts for May 22 and 24

JUPITER starts May with a low altitude conjunction with Mars, Sky chart for May 1. Jupiter gets steadily higher in the morning sky during the month. In the process it passes Venus and Mercury on the 12th, when it will be 35', just over the diameter of the full moon, to the left of Venus with Mercury beyond Venus and 2° from Jupiter. Sky chart for May 12

During the rest of May, Jupiter will move away from the other three planets, so that by the last morning it will be 19° above Venus and the crescent moon, a little less above Mars. The moon, 9% lit, will be closer to Jupiter the previous night when it 7.5%deg; below and slightly left of the planet. The previous morning, the moon with a little thicker crescent, will be 9.5° to the upper left of Jupiter.

SATURN will not be taking part in the conjunctions. It will be best seen in the evening sky. At the beginning of May the planet will be due north and highest at about 10.30pm for NZ, about two hours earlier by the 31st. The planet will be 13° to 14° from the star Spica, which will be to the right of Saturn early evening but, as the sky rotates during the evening, be more nearly above the planet.

Following opposition in April, the Earth will be moving away from Saturn. Their separation will be 1305 million km on May 1, increasing to 1357 million km by May 31. One effect of the increasing distance is to make the rings appear slightly less open as seen from the Earth.

The 87% lit moon will be just over 7° above and left of Saturn on May 14. The following night the moon will be 2.5° above Spica.

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Planets in the Morning Sky

The charts below show the grouping of the planets as seen to the east-north-east on a number of mornings during May. The circle on each chart represents a 5° field of view, which is typical of many binoculars.
Planets on May 1 and 7  |  Planets on May 12 and 16  |  Planets on May 22 and 24  | 

The circle on the chart represents a field 5° in diameter, typical of binoculars.

The circle on the chart represents a field 5° in diameter, typical of binoculars.

The circle on the chart represents a field 5° in diameter, typical of binoculars.

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