Skynotes April 2017

Skynotes

Share this

Month Highlights

Mars is hard to find, very low to the western horizon after sunset but over in the east Jupiter is stunningly bright as it reaches opposition on the 8th. Saturn rises late in the evening and is found high overhead by sunrise. By the middle of the month, Venus joins Saturn in the morning sky.

Planetarium Event

On the evening of Wednesday 12th, the Planetarium will join the world-wide celebration to mark humanity’s first trip into space - the flight of Russian cosmonaut, Yuri Gagarin. Yuri’s Night Space Party will feature a DJ, an engaging discussion on space exploration and a planetarium show that will take you on a journey to the far reaches of the universe.

School Holidays

Scienceworks is open daily from 10am – 4:30pm during the school holidays (1–17 April, excluding Good Friday). Planetarium session times are:

12pm: Tycho to the Moon - meet Tycho, a dog who doesn't just howl at the Moon but wants to go there!

1pm: Tilt - come on a whirlwind adventure to find out how the seasons work.

2pm: Capturing the Cosmos - a new way of looking at the sky to better understand our universe.

3pm: Our Living Climate - explore the science of Earth's amazing and ever-changing climate.

See the Melbourne Planetarium's What's On listing for more details.

Sunrise & Sunset Times

Date  Rise Set
Saturday 1st 7:33* 7:13*
Tuesday 11th 6:42 5:59
Friday 21st 6:51 5:45
Sunday 30th 7:00 5:34
*Daylight savings ends at 3am, Sunday 2 April

Moon Phases

First Quarter Tuesday 4th
Full Moon Tuesday 11th
Last Quarter Wednesday 19th
New Moon Wednesday 26th

The Moon will be at perigee (closest to Earth) on Friday 28th at a distance of 359,323 km.

The Moon will be at apogee (furthest from Earth) on Saturday 15th at a distance of 405,477 km.

Let the Moon Be Your Guide

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

  • After sunset on the 1st, the waxing crescent Moon is very close to Aldebaran (Taurus, the bull).
  • On the 4th, Pollux and Castor, the twin stars of Gemini, are just below the First Quarter Moon.
  • The waxing gibbous Moon is to the right of the star Regulus (Leo) on the 7th.
  • The Full Moon rises below Jupiter and Spica (Virgo) on the night of the 11th.
  • During the early hours of the 17th, the waning gibbous Moon sits below Saturn.
  • Before sunrise on the 24th, the waning crescent Moon is to the right of Venus.
  • After sunset on the 28th, the waxing crescent Moon sits between the red giant star Aldebaran and the red planet Mars, low to the western horizon.
  • On the 30th, the large and bright star Betelgeuse (Orion) is above and to the left of the thin crescent Moon.

Planets

Mercury is too close to the Sun to be seen this month.

Venus returns to the morning sky by the middle of the month and can be seen low towards the eastern horizon. The thin crescent Moon sits to the right of Venus on the 24th.

Mars is very low to the western horizon and will be hard to see with the glow of evening twilight.

Jupiter can now be found rising in the east at sunset, with the bright star Spica (Virgo) sitting to the right. Jupiter is lovely and bright throughout the month because it reaches opposition on the 8th. This means it lies in the opposite part of the sky to the Sun and we will see Jupiter all night long. Jupiter is also closest to us during opposition because Jupiter and the Earth are located together on the same side of the Sun. The Full Moon travels across the sky with Jupiter on the 11th.

Saturn rises late in the evening and can be seen high in the north before sunrise. It is in chase of Scorpius, one of the most easily recognisable constellations due to its curving line of stars. On the morning of the 17th, the Moon sits below Saturn.

Meteors

The Lyrids is the main meteor shower in April. It is centred near the bright star Vega, which appears low to the northern horizon around 3am. The Lyrids is active between the 16th and the 25th, with a peak around the 22nd. Its hourly rate typically reaches 10, but there was an outburst in 1982 when the meteor rate peaked briefly at 90 meteors/hour.

The Pi-Puppids is better placed for us but it is not a persistent shower. It is associated with Comet Grigg-Skjellerup and, being a relatively new shower, has periods of inactivity when the comet is far from the Sun. It peaks around the 23rd and the centre of the shower lies low in the south-west to the right of the bright star Canopus in Carina, the keel.

The delta Pavonids, which began in March, peaks on the 6th. This shower is centred on the little known constellation of Pavo, the peacock, which lies near the South Celestial Pole.

There should also be some meteor activity centred on Scorpius and Sagittarius that is best seen after midnight. Meteor activity in this region of the sky runs from the 15th through until July, with several peaks within this time.

Stars & Constellations

The Southern Cross can be found high in the south-east with the Two Pointers trailing behind. To the right of the Cross, in the south-western sky, is the star Canopus, the second brightest star in the night sky. Low in the south is Achernar, the head of the river Eridanus. Achernar never sets in Melbourne and is called a circumpolar star, along with the Southern Cross and the Two Pointers (Alpha and Beta Centauri).

April is the month for catching both the summer constellation of Orion, the hunter and the winter constellation of Scorpius in the sky together for a brief time after sunset. Orion can be seen lying on his side low in the west below Sirius, the brightest star in the night sky. Scorpius can be found rising in the east with the red star Antares marking the Scorpion’s heart.

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:

6:04am – 6:13am, Monday 3rd April.

The Station will appear in the west near bright Jupiter and travel across to the south-east, passing very close to Alpha Centauri.

Predictions of when to see the ISS can be obtained from the Heaven's Above website.

On this Day

1st 1948, Alpha, Bethe and Gamow publish their famous paper analysing the 'hot Big Bang'.

2nd 1845Fizeau and Foucault take the first photograph of the Sun.

3rd 1966Luna 10 (USSR) became the first spacecraft to orbit the Moon.

4th 1979Voyager 1 (USA) discovered the rings of Jupiter.

7th 1795, France adopts the metric system.

11th 1970Apollo 13 (USA) was launched on its ill-fated mission.

12th 1961Yuri Gagarin (Vostok 1 USSR) became the first human in space.

12th 1981Columbia (USA) was the first space shuttle to be launched.

14th 1611, The word "telescope" is first used, by Prince Frederico Cesi.

18th 1971Salyut 1 (USSR), the first space station, was launched.

23rd 1971, First manned docking with a space station (USSR) was performed.

24th 1990, The Hubble Space Telescope (HST) was launched on the space shuttle Discovery.

26th 1920, Harlow Shapley and Heber Curtis debated "The Scale of the Universe".