Skynotes May 2017


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Month Highlights

Jupiter is looking stunning in the evening sky and it is joined by Saturn rising in the east. Mars is hard to find low to the north-west horizon after sunset. By morning, brilliant Venus leads the way to Mercury.

Regulus Hides Behind the Moon

During the early evening on the 4th, the Moon will pass directly in front of the bright star Regulus. The star will be hidden behind the Moon for just over an hour.

Every 9 years, the Moon’s path aligns with the star Regulus, in the zodiac constellation of Leo the lion. For a period of time, we see the Moon pass directly in front of or occult the bright star as the Moon passes by each month.

There was an occultation back in February but it was clouded out for most of Australia. This one occurs during the early evening, making it nice and easy to catch.

The Moon will meet up with Regulus at 8:09pm, when the star will disappear behind the dark or unlit side of the Moon. The star will emerge from bright part of the Moon at 9:21pm. The Moon will be easy to see in the northern sky. It’s best to observe a few minutes before Regulus disappears and it should be possible to see Regulus a few minutes after the expected reappearance time. The reappearance will be the most difficult to spot against the bright light of the Moon.

Discover the Night Sky

The Melbourne Planetarium presents its popular astronomy sessions each Thursday night. All evenings include a glass of wine with cheese, the opportunity to chat to the Planetarium’s astronomer, Dr Tanya Hill, and to be immersed in a planetarium experience. You will finish the evening stargazing through telescopes (weather permitting). For more information, pricing or bookings please call the Scienceworks Booking Office on 9392 4819 or see the What's On.

Thursday 4th: Ticket to the Universe – come on a tour of our amazing universe.

Thursday 11th: The Milky Way Galaxy – what do we know about the galaxy we call home?

Thursday 18th: Dark Energy – we don’t know what makes up most of the universe, but that’s where the fun begins.

Thursday 25th: Black Holes and Gravitational Waves – gravitational waves can teach us about black holes and so much more.

Sunrise & Sunset Times

Date Rise Set
Monday 1st 7:00 5:33
Thursday 11th 7:09 5:22
Sunday 21st 7:18 5:14
Wednesday 31st 7:25 5:09

Moon Phases

Phase Date
First Quarter Wednesday 3rd
Full Moon Thursday 11th
Last Quarter Friday 19th
New Moon Friday 26th

The Moon will be at perigee (closest to Earth) on Friday 26th, at a distance of 357,209 km.

The Moon will be at apogee (furthest from Earth) on Saturday 13th, at a distance of 406,210 km.

Let The Moon Be Your Guide

The Moon can be used as a pointer to find other objects in the sky:

  • The waxing crescent Moon is near the twin stars of Gemini, Castor and Pollux after sunset on the 1st.
  • At 8:09pm on the 4th, the waxing gibbous Moon will pass in front of the bright star Regulus (Leo, the lion) briefly hiding it from view. The star will reappear at 9:21pm.
  • On the night of the 7th, the Moon is near bright Jupiter.
  • The Full Moon on the 11th sits at the head of Scorpius.
  • Throughout the night of the 13th, the waning gibbous Moon is near Saturn.
  • Before sunrise on the 23rd, the waning crescent Moon sits below bright Venus.
  • Then on the 24th, the Moon is just above faint Mercury.
  • After sunset on the 27th, low to the western horizon the waxing crescent Moon can be found above Mars.
  • On the 29th, the Moon is back with Castor and Pollux (Gemini) in the evening sky.
  • After sunset on the 31st, the Moon is near bright Regulus.


Mercury can be seen low to the north-east horizon before sunrise. You can look for it below bright Venus. On the 24th, the crescent Moon will sit just above Mercury.

Venus is the lovely morning star, shining brightly in the north-east before sunrise. The thin crescent Moon sits just below Venus on the 23rd. Passing by Venus, but much too faint for the eye to see is the dwarf planet Eris.

Mars continues to hover low in the north-west during evening twilight. It’s the hardest of the planets to see this month. If you have a great view of the horizon, try spotting the thin crescent Moon sitting above Mars on the 27th.

Jupiter continues to dazzle, shining brilliantly in the north-east after sunset. By late in the evening Jupiter can be found high in the north. The bright star to the right of Jupiter is Spica (Virgo, the maiden). The Moon sits to the left of Jupiter on the 7th. As a point of interest, two dwarf planets Haumea and Makemake sit below Jupiter this month. They are towards the bright star Arcturus (Bootes, the herdsman) although they are too faint to be seen, even with an amateur telescope.

Saturn moves into the evening sky, rising a couple of hours after sunset. It can be found near the brightest part of the Milky Way which marks the centre of our Galaxy. Above Saturn is Scorpius the most easily recognisable of all the winter constellations. The Moon joins Saturn on the night of the 13th.


The Eta Aquarids is linked to Comet Halley and is usually a good shower for the southern hemisphere, with typical rates reaching 30 meteors per hour. The peak of the shower is on the 6th. Eta Aquarids are often very fast, usually yellow in colour and with persistent trains. The meteors appear to come from the constellation Aquarius, which can be found in the north-east before sunrise.

There are also some minor meteor showers centred on the constellations of Scorpius and Sagittarius that can be seen until July. The best time to look for meteors is between midnight and dawn.

Stars & Constellations

The constellation of Scorpius can be seen rising in the south-east. The scorpion's heart is marked by the red star Antares. This is a very rich area of the Milky Way and the scorpion's tail contains many beautiful star clusters that can be seen with binoculars.

The brightest star in the night sky, Sirius, is low to the western horizon. Lying above and to the south of Sirius is Canopus, the second brightest star in the night sky. Canopus belongs to the constellation Carina (the keel).

Prominent in the northern sky is the constellation of Leo, the lion. We view Leo upside down compared to the Northern Hemisphere, so to find Leo, look for an upside down question mark or sickle shape. The brightest star in this constellation is Regulus, meaning ‘little king’.

International Space Station

From Earth, the ISS appears as a bright star that steadily moves across the sky. It can often be seen from Melbourne, for example at:

6:27pm – 6:33pm, Tuesday 2nd May.

The Station will appear towards the north-west and travel below the bright stars Betelgeuse (Orion) and Sirius (Canis Major) before disappearing in the south-east below the Southern Cross.

Predictions of when to see the ISS can be obtained from the website:

On This Day

1st 1958, the powerful Van Allen radiation belts (concentrations of electrically charged particles that surround Earth) are discovered.

4th 1989, Magellan the first planetary mission launched from the Space Shuttle, is sent to study Venus.

5th 1961, Alan Shephard Jr (Mercury 3) became the first American to be launched into space.

7th 1992, the Space Shuttle Endeavour blasts off on its maiden voyage. It was the 47th shuttle mission.

8th 1963, the first transatlantic colour TV pictures were sent via Telstar 2 (USA).

9th 1962, a laser beam was bounced off the Moon from Earth by MIT scientists.

11th 1916, Albert Einstein’s ‘General Theory of Relativity’ was first presented.

14th 1973, Skylab 1, the USA’s first space station was launched.

16th 2011, the Space Shuttle Endeavour was launched on its 25th and final mission.

18th 1991, Helen Sharman, the first Briton in space, blasts off on board a Soyuz spacecraft.

18th 1969, Apollo 10 was launched. It was a full dress rehearsal for the Apollo 11 mission without actually landing on the Moon.

19th 1919, Sir Eddington (UK) observes a total solar eclipse and validates Einstein's General Theory of Relativity.

20th 1990, The Hubble Space Telescope sent its first photograph from space, an image of a double star 1,260 light years away.

25th 1961, President John F. Kennedy launches the USA’s race to the Moon.

28th 1959, Rhesus monkey Abel and squirrel monkey Baker were launched for a brief suborbital space flight in the nose cone of Jupiter Missile AM-18.