NGC 3532, the Pincushion Cluster, is an open cluster in the constellation Carina. Its population of some 150 stars of 7th magnitude or fainter includes seven red giants and seven white dwarfs. Also commonly known as the Football Cluster, the Black Arrow Cluster and the Wishing Well Cluster, on May 20, 1990, it became the first target ever observed by the Hubble Space Telescope. Photo by MPAS member Steven Mohr
Highlights this month
- 1SatUranus in superior conjunction with the Sun — lost in the glare. (6:29am)
- 4TueThe Moon passes Saturn — 4° apart. (4:47am)
- 5WedThe Moon passes Jupiter — 4° apart. (9:55am)
- 6ThuEta Aquariids meteor shower peaks (up to 50/hr). A 26% Moon washes out fainter meteors for part of the night.
- 16SunThe Moon passes Mars — 1° apart. (2:56pm)
- 17MonMercury at greatest evening elongation (22° from the Sun, mag 0.4) — best evening apparition. (3:44pm)
- 24MonSaturn is stationary — begins retrograde (westward) motion. (5:33am)
- 30SunMercury is stationary — begins retrograde (westward) motion. (12:00pm)
- 31MonThe Moon passes Saturn — 4° apart. (1:08pm)
The beautiful section of the Milky Way around Crux, the Southern Cross – including the dark nebula known as the Coalsack – takes centre stage looking south in May. There are several fine open clusters on view in Carina, many nestled among the rich star fields of the Milky Way. NGC 3532, the Pincushion Cluster, can be seen with the naked eye, but binoculars reveal its many twinkling stars well. The magnitude 4.2 cluster NGC 3114 is an interesting target for a small telescope, while NGC 2516, the Southern Beehive, is a good target for binoculars.
The large constellation Centaurus, the Centaur, sits within the stunning star fields of the Milky Way. It is home to what is arguably the finest globular cluster in the whole night sky – the magnificent Omega Centauri, or NGC 5139.
The constellation’s two brightest stars are Alpha and Beta Centauri, known more familiarly to astronomers as Rigil Kentaurus and Hader. The constellation is fully visible between the latitudes of 25°N and 90°S. For reference, the MPAS observatory at Mount Martha is located at 38°S.
This year the annual Eta Aquariid meteor shower peaks around May 6-7 and is caused by the dust left over from Halley’s Comet entering our atmosphere and vaporising. You can expect to see roughly 30 meteors an hour if you are very lucky. The meteors appear to be coming from a point near the star Eta Aquarii in Aquarius, and tend to be quite fast-moving. The further south you are, the better view of the shower you will get.
The easiest way to find the location of the constellations is to simply download a free app to your phone, such as Stellarium, Sky Map, SkySafari, or Star Walk 2. Once installed, just hold your phone up and explore the night sky, identify stars, constellations, planets, clusters, and so on.
By Nerida Langcake
This article appeared in the May 2021 issue of the Mornington Peninsula Magazine.
The sky in detail — May 2021
Sun & twilight
| Date | Sunrise | Sunset | Day length | Astro. dark begins | ends |
|---|---|---|---|---|---|
| Sat 1 | 7:01am | 5:32pm | 10h 31m | 7:02pm | 5:32am |
| Mon 10 | 7:10am | 5:23pm | 10h 13m | 6:53pm | 5:39am |
| Thu 20 | 7:18am | 5:14pm | 9h 56m | 6:47pm | 5:46am |
| Mon 31 | 7:27am | 5:08pm | 9h 42m | 6:42pm | 5:53am |
Days shorten by about 49 minutes over the month.
The Moon
- Last QuarterTue 4, 5:50am
- New MoonWed 12, 5:01am
- First QuarterThu 20, 5:20am
- Full Moon SupermoonWed 26, 9:15pm
Apogee 12 May (406,300 km) · Perigee 26 May (356,900 km)
The planets
Rise/set for mid-month at The Briars.
| Planet | In | Mag | Rise | Transit | Set | Best |
|---|---|---|---|---|---|---|
| Mercury | Tau | 0.1 | 9:10am | 1:47pm | 6:23pm | Hidden |
| Venus | Tau | −3.7 | 8:20am | 1:10pm | 6:00pm | Hidden |
| Mars | Gem | 1.7 | 11:05am | 3:45pm | 8:26pm | Evening |
| Jupiter | Aqr | −2.1 | 12:17am | 6:58am | 1:40pm | Morning |
| Saturn | Cap | 0.5 | 10:50pm | 5:53am | 12:52pm | Morning |
| Uranus | Ari | 5.9 | 6:11am | 11:25am | 4:38pm | Hidden |
| Neptune | Psc | 7.9 | 2:09am | 8:23am | 2:38pm | Morning |
Meteor showers
- Eta Aquariids — peaks 6 May, radiant in Aquarius (up to 50/hr). Debris of Halley's Comet and one of the best showers of the year from the south — swift meteors in the pre-dawn eastern sky. A 26% Moon washes out fainter meteors for part of the night.
Computed for The Briars, Mt Martha. Times are local (Melbourne).
Generated automatically from the MPAS sky engine on 15 July 2026.
The solar system — May 2021
Evening sky Morning sky Up much of the night Lost in the Sun’s glare
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