Skynotes January 2013

Month Highlights

Jupiter is the planet to see this month, outshining all the evening stars. Mars is also in the evening sky but low to the western horizon. In the early morning, Saturn can be found high in the east, Venus is low to the eastern horizon and Mercury is only visible for a few days.

Summer School Holidays

Scienceworks will be opened daily from 10am – 4:30pm during the school holidays (26th December – 29th January). 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: Stories in the Stars: the night sky of the Boorong people – see Victorian constellations come to life

2pm: Tilt – discover the reasons for seasons

3pm: Black Holes: Journey into the Unknown – a place where the unimaginable becomes reality

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

Winning sky photographs - 2012 David Malin Awards

Spectacular images of the night sky are on show at the Melbourne Planetarium. This display features the winners and selected entries from the annual photography competition inspired by the world-renowned astronomy photographer and competition judge, Dr David Malin. The exhibition was developed by the Central West Astronomical Society and toured by the Powerhouse Museum, Sydney.

Sunrise & Sunset Times

Moon Phases

The Moon will be at apogee (furthest from Earth) on Tuesday 22nd at a distance of 405,311 km.

The Moon will be at perigee (closest to Earth) on Thursday 10th at a distance of 360,047 km.

Let the Moon be Your Guide

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

• The waning gibbous Moon sits above the star Regulus, on the morning of the 2nd.
• During the early hours of the 6th, the Moon is very close to Spica.
• On the morning of the 7th, the waxing crescent Moon sits above Saturn.
• The Moon is near red Antares (Scorpius) on the morning of the 9th.
• Before sunrise on the 10th the Moon sits above Venus.
• The waxing crescent Moon sits to the right of Mars after sunset on the 14th.
• The waxing gibbous Moon is near the star cluster Pleiades on the evening of the 21st.
• Then on the 22nd, the Moon can be found near Jupiter.
• On the 26th, the almost full Moon sits above the twin stars of Gemini – Castor and Pollux.

Planets

Mercury can only be seen for a few days at the start of the month. It is very low to the eastern horizon at sunrise. Look for bright Venus and Mercury sits below and to the right. Mercury will reappear in the evening sky next month.

Venus is low in the east before sunrise, but remains lovely and bright. On the 1st, Mercury can be seen below Venus and on the 10th the thin crescent Moon sits above Venus.

Earth will be at perihelion (closest approach to the Sun) on Wednesday 2nd, at a distance of 147 million km. However, this is not why summer is warm. The seasons happen because the Earth’s axis is tilted and as the Earth moves along its orbit, the tilt changes the Sun’s position in the sky. During summer, the Sun travels high in the sky, the sunlight hitting the ground is more concentrated and the days are longer.

Mars can be found low in the west after sunset and by the end of the month it disappears in the glow of twilight. On the 14th, the thin crescent Moon sits to the right of the red planet.

Jupiter is shining brilliantly in the evening sky after sunset. It is paired up with the red star Aldebaran in the north-eastern sky. To the left of Jupiter is the bright star cluster Pleiades. The Moon sits near Jupiter on the 22nd.

Saturn is high in the east at sunrise with the bright star Spica sitting above and to the left. Across to the right is the constellation of Scorpius. Look for three bright stars that form a triangle around Saturn – red Antares (Scorpius), white Spica (Virgo) and orange Arcturus (Bootes). On the 7th, the Moon sits just above Saturn.

Meteors

The year starts slowly for meteor showers. The month’s most active shower, the Quadrantids, is a strong Northern Hemisphere shower. Sometimes it is possible to spot some long-pathed meteors around the peak of the shower on the 4th.

The shower best suited for viewing in the Southern Hemisphere is the Eta Carinids which is active from 14th to 27th. The meteors are typically faint, with hourly rates of only 2 or 3 at the shower’s peak around the 21st. The shower is centred near the faint star Eta Carina, which is one of the most massive stars in our Galaxy. Eta Carina is found near the Southern Cross and is high in the south from midnight to dawn, the ideal time for meteor observing.

Stars and Constellations

Orion, the hunter, is now high in the north-eastern sky and easily located by the three bright stars that form his belt. In Australia, we recognise the belt as the base of the Saucepan. The handle of the Saucepan (also known as the sword of Orion) contains a spectacular nebula that is a birthplace of new stars. This cloud of glowing gas is 1,500 light-years away but is still easily visible through binoculars. Above the Saucepan is the blue-white supergiant star Rigel and below is the red supergiant star Betelgeuse.

On the western side of Orion is the hunter’s prey Taurus, the bull. A small triangle depicts the face of the bull with the brightest star in the group being the red giant, Aldebaran. Aldebaran sits in front of a widely spread cluster of about 200 stars called the Hyades. Taurus also contains a second cluster, the Pleiades (or Seven Sisters), which is the brightest and most famous star cluster in the sky. Approximately seven stars can be seen with the naked eye but binoculars reveal many more.

The Southern Cross and the Two Pointers are low in the south-east, which means that the Magellanic Clouds, two of our nearest galaxies, are high in the sky. They sit opposite the Southern Cross and away from city lights, they appear as two fuzzy patches or ‘clouds’.

International Space Station

The ISS orbits the Earth every 90 minutes at an average distance of 400 km. The ISS appears as a bright star that steadily moves across the sky. It can often be seen from Melbourne, for example at:

9:57pm – 10:03pm on Friday 4th January

The Station will appear above the north-west horizon and travel past Jupiter and Sirius before disappearing in the south-east.

Predictions of when to see the ISS can be obtained from the website: www.heavens-above.com

On this Day

1st 1801, the first asteroid, Ceres (now called a dwarf planet), was discovered by Giuseppi Piazzi (Italy).

2nd 1839, Louis Daguerre (France) takes the first photograph of the Moon.

2nd 1959, Luna 1 (USSR) was launched and became the first spacecraft to fly by the Moon and orbit the Sun.

4th 1958, the first satellite, Sputnik (USSR), fell back into the atmosphere and disintegrated.

5th 1972, the Space Shuttle (USA) program was launched.

6th 1892, an aurora was first photographed.

7th 1610, Galileo Galilei discovered the Jupiter's four largest moons: Io, Europa, Callisto and Ganymede.

9th 1839, Thomas Henderson (South Africa) is the first person to measure the distance to a star other than the Sun, Alpha Centauri.

9th 1998, an international team including Australians announces the discovery that the expansion of the Universe is accelerating.

10th 1946, the US Army Corps bounce a radar signal off the Moon, showing that radio waves could penetrate the atmosphere.

11th 1787, Sir William Herschel discovered the first moon of Uranus.

22nd 1997, Lottie Williams (USA) becomes the only person known to have been hit by space junk when she is struck in the shoulder by a piece of metal, believed to have been part of a Delta II rocket.

24th 1986, Voyager 2 (USA) made the first flyby of Uranus and sent back close-up pictures of the planet.

27th 1967, the Apollo 1 (USA) fire kills crew of 3.

28th 1986, the space shuttle Challenger (USA) explodes after lift-off killing all seven crew members.

31st 1958, Explorer 1, was the first USA satellite launched.