The Moon is New on April 30th and May 30th. On April 30th there will be a partial solar eclipse, visible only from south-west South America and the nearby Pacific, and Porrima (gamma Virginis), will be occulted by the Moon on May 13th, disappearing soon after 1.46 a.m. and reappearing soon before 2.36 a.m.. The Moon will be Full on May 17th (UK), during which there will be a total lunar eclipse visible on the 16th from South America. If you watched the recent BBC production of Around the World in 80 Days, you’ll understand the difference in dates.
The planet Mercury was at greatest elongation from the Sun on April 29th, and close to the Pleiades that night, on the 30th and on May 1st. Mercury will be close to the Moon on the 2nd. Though growing fainter, it will still be brighter than Aldebaran in Taurus, setting to its left. Growing still fainter and setting about 10 p.m., Mercury will disappear in mid-May, at inferior conjunction on this side of the Sun on May 21st, and will reappear in the morning sky mid-June.
Venus rises about 4.00 a.m. in May, and will be very near Jupiter on May 1st. The Moon, Jupiter, Mars and Venus are all close from May 25th to 27th, with Venus nearest to the Moon on the 27th, and occulted by it as seen from southeast Asia and China.
Mars rises at 3.30a.m. in May in Capricornus, below and to the right of Venus, passing on into Aquarius and then Pisces. On April 24th – 27th the waning crescent Moon passed below Saturn, Mars, Venus and Jupiter, all low down in the twilight and best seen with binoculars, and the event will repeat on May 25th – 27th. Mars will be within a degree of Jupiter on May 28th, closer still on the 29th and 30th, after passing Neptune on the 18th.
Jupiter returned to the morning sky in April, in Pisces, in good time for its close encounters with Venus on April 30th and Mars on May 29th..
Saturn, also in Capricornus, rises in the morning sky about 2.30 a.m., and joins the predawn grouping of the planets above for May and June, near the Moon on the 22nd. Vesta, the brightest of the asteroids, will be 2 degrees southwest of Saturn at the beginning of May and passes 0.6 degrees to the south of it on May 7th.
Uranus in Aries is the only planet not taking part, having disappeared by May and in superior conjunction on the far side of the Sun on the 5th.
Neptune is in Pisces, rising about 3.30 a.m. in May, near the Moon on the 24th. Neptune’s morning encounter with Mars on May 18th is its only planetary encounter in this quarter.
Before dawn on May 31st there may be a spectacular meteor shower from Comet Schwassman-Wachman 3 – though as usual with such events, nothing is guaranteed, even for places where it will be dark (see below). The comet is in a short-period orbit, captured by Jupiter into a relatively tight ellipse around the Sun with a period of 5.4 years. It was discovered in 1930, when it made a close pass by the Earth, and there were unconfirmed reports of a brief meteor shower. The meteors were designated the ‘Tau Herculids’, as they appeared to be coming from near that star, but subsequent observations put the radiant on the east of Boötes, near Corona Borealis. In 1995 the comet flared in brightness and split into three pieces. In 2006 the largest piece was to have been the target of the US Contour spaceprobe, but that failed in flight. Images that year by the Hubble Space Telescope and others showed that the comet had continued splitting into a long trail of at least 68 fragments, like those of Comet Shoemaker-Levy before they hit Jupiter in 1994.
On May 31st the Earth may encounter dust streams emitted by the comet in 1882, 1887 and 1995, occurring in reverse order at 5.55, 6.04 and 6.17 a.m. British Summer Time. There will be no interference from the Moon, which will be New, but – you guessed it! – in Orkney the Sun rises at 4.12 that morning, and at 4.41 here in Troon, so there’s no chance of seeing any meteors unless they’re very bright. At this time of year there’s a better chance of seeing noctilucent clouds, in the north around midnight, in June or July.
News of the James Webb Space Telescope continues to be good, with all the instruments now cooled down to operating temperature, including the final cryogenic cooling of the Middle Infrared Instrument (MIRI), which is now at its design temperature, 7 degrees above Absolute Zero. Testing and fine tuning of the instruments will continue, but it’s still anticipated it will be complete some time during June.
Duncan Lunan’s most recent book, The Other Side of the Interface, was published by Other Side Books at the beginning of 2021, and is available through Amazon or through bookshops, or from the publishers. For details and for his other books see Duncan’s website, www.duncanlunan.com.
May Sky Map can be downloaded here: