What’s in the Sky - May 2021
Last Quarter 4th
New Moon 12th
First Quarter 20th
Full Moon 26th
Mars is in the northwestern sky after sunset in the constellation of Gemini.
Mercury returns to the western evening twilight sky for a short time from the middle of the second week of May before becoming lost once again in the twilight at months end. Mercury is in the constellation Taurus.
Venus: is low in the western twilight sky, moving from the constellation Aires to Taurus in the middle of the first week of May.
Saturn is visible high in the eastern morning sky in the constellation Capricornus. Saturn will remain in Capricornus until 2023.
Jupiter is also high in the eastern morning sky below Saturn and is in the constellation Aquarius.
Worth a Look:
4th: The waning crescent Moon is to the right (south) and slightly above the ringed planet, Saturn.
5th: The waning crescent Moon is to the right (south) and above the largest planet in our Solar System, Jupiter.
7th: The Eta Aquarid meteor shower (see below for details).
13th: The thin crescent Moon is just above and slightly to the right (north) of Venus. Mercury is slightly above and to the north of the Moon. With both planets and the Moon close to the horizon, this provides a good opportunity for widefield photographers. 16th: The waxing crescent Moon is just below and slightly to the right (north) of the red planet, Mars.
26th: A total lunar eclipse occurs in the evening (see details below). This is an excellent opportunity for photographers.
7th: The Eta-Aquarid meteor shower which Halley’s Comet and is one of the most popular in the southern hemisphere. Meteor showers occur when the Earth crosses the orbit of a comet and encounters a trial of debris/dust left by the comet and we see lots of meteors appearing to come from one area of the sky. This is called the radiant and each shower is named after the constellation or bright star near which the radiant appears. In this case it’s the constellation Aquarius and the radiant is near the star Eta Aquarii. The shower is active from 19th April until 28th May with the peak occurring on the morning of the 7th May. The best time to observe any meteor shower is after midnight, usually a few hours before dawn, so on the morning of the 7th, look towards the east. At its peak the rate will often be around 50 per hour. The Eta Aquarids are usually very swift and are a striking yellow colour. They are also known for their trains with about 25% of meteors leaving a train behind. There will be a waning gibbous Moon in the early hours of the morning which may interfere with observations, however the brighter meteors should still be visible especially if you are away from city lights.
The Eta-Aquarids have a history of good performance. In 1975 there was an hourly rate of 95 and in 1980, an hourly rate of 110!
Despite the lighter skies from the moonlight, it provides a good opportunity for wide-field imagers, though with the Eta Aquarids being fairly swift moving, it will take patience and a wide angle lens with short continuous exposures to capture a meteor or two!
Total Lunar Eclipse
26th: This month your eyes are all you the equipment you will require to see a special astronomical event. A lunar eclipse is an event that anyone can enjoy and this month we are especially lucky that we see a total lunar eclipse on Wednesday 26th May.
Lunar eclipses occur when our closest celestial neighbour in space, the Moon passes through the Earth’s shadow and can only occur at Full Moon. This time, the Moon does not pass deep into the Earth’s shadow so it will likely turn a light coppery hue. Observers Australia and New Zealand will have the best view as they will see the entire eclipse.
Lunar eclipses are an excellent opportunity for photographers as no special equipment (solar filters etc.) are required to view and image the event.
Timings for the eclipse in Australia are listed in the table below.
Eclipse EST WST NZST UT (26 May) (26 May) (26/27 May) (26 May)
Penumbral Begins 6:47pm 4:47pm 8:47pm 08:47
Partial Begins 7:45pm 5:45pm 9:45pm 09:45
Totality Begins 9:10pm 7:10pm 11:10pm 11:10
Mid-Eclipse 9:19pm 7:19pm 11:19pm 11:19
Totality Ends 9:28pm 7:28pm 11:28pm 11:28
Partial Ends 10:53pm 8:53pm 12:53am* 12:53
Penumbral Ends 11:49pm 9:49pm 01:49am* 13:49
* 27th May.
It is difficult to predict the colour of totality in advance and this is perhaps one of the most magical aspects of total eclipses of the Moon. Whether this is your first eclipse or one of many, this unpredictability makes each and every eclipse exciting and definitely worth a look. Make sure you don’t miss out on your chance to view something a little different this month!
Want to know more about lunar eclipse? Check out my lunar eclipse page here.
You can download a star map for April here.
Dawes G., Northfield P., Wallace K. (2020). Astronomy 2021 Australia, Quasar Publishing.
Lomb, N. (2020). 2021 Australasian sky guide. Ultimo, NSW: Museum of Applied Arts and Sciences Media.
NASA (2013). Lunar Eclipses: 2021 - 2030. NASA. Accessed 24 April 2021, https://eclipse.gsfc.nasa.gov/LEdecade/LEdecade2021.html.