Category: What’s Up?

Looking at the Last Quarter Moon during the early morning hours of June 13, it can be seen passing within a few degrees of the red planet Mars. (Another planet, Neptune, is also there, but invisible without binoculars).
On June 19, just before sunrise, low in the east the almost-New Moon will be next to brilliant Venus, in the vicinity of the distinctive ‘V’ pattern of stars which includes the conspicuous star Aldebaran. Western astronomers know this as part of the constellation Taurus the Bull.

The Boorong people of north-west Victoria were reputed to be keen and renowned astronomers. Tragically they and their culture were displaced, dispersed or destroyed as their lands were taken, and we have only second hand accounts of their knowledge. It is believed they saw Aldebaran as part of the constellation of Gellarlec the Songman, who keeps the essential knowledge of the people. Gellarlec’s name may be derived from that of the pink cockatoo, also a songster, and whose salmon colouring corresponds to that of Aldebaran’s.

Just west of Melbourne, the Wathaurong people have left physical traces of their astronomy, at Wurdi Youang. This is an arrangement of about a hundred large basalt stones in a shape somewhat like the silhouette of an ice-cream in a cone. The two straight sides of the cone point directly to the midsummer and midwinter sunsets, with the line of symmetry between them pointing directly East-West. Sadly much knowledge of this construction was suppressed by missionaries and lost.

Midwinter Solstice occurs this year on June 21. It may be of interest to learn that, whereas the Winter Solstice is the day with the least hours of daylight, it is usually not the day with the latest sunrise and earliest sunset. Due to the elliptical orbit of the Earth, these may occur a few days either side of the Solstice.

The opposition of Earth and Jupiter, when the two planets are at their closest, occurs on July 14, and the opposition of Earth and Saturn, on July 21. With more than a year until the next oppositions and the two planets’ proximity in the early night sky (in the east from dusk onwards), mid-July is the perfect time to view these magnificent gas giants. If you have access to a telescope there is a wealth of viewing objects: Jupiter’s four moons, its weather (particularly the Great Red Spot, the largest known cyclone in the Solar System), Saturn’s eight moons, and, of course, the Rings. (If you are looking at any of these moons, there are charts available so that you can identify them.) Even for the unaided eye, Jupiter is brighter than any of the stars in the night sky – but it will be upstaged on the evening of July 5, when the Full Moon, Saturn, and Jupiter will make an outstanding line-up.

By Vlack

By Vlack

If you are outside at about 2 a.m. under a clear sky in April, face the east, and you will see a striking trio of planets lined up above: reddish-orange Mars, yellowish Saturn, and the highest and brightest, Jupiter. Mars is relatively close to Earth now, and with binoculars, you may see it as a disc, not just a red dot; and you may also see the rings of Saturn and the moons of Jupiter. Between the 15th & 17th of April,the Moon, in its Last Quarter phase, will be passing near these three planets.

If you’re watching later on in the morning, say around 6 a.m., you can see another planet added to the view: Mercury, which rises about 5 a.m. in mid
April. For the planet-watcher, Mercury can be elusive, usually hidden by -or outshone by- the Sun. But now, for a few weeks, we have the best views of it until much later in the year. On April 22nd the Moon will be very close to Mercury- although with the Moon almost New, and only just above the horizon at dawn, it may be hard to spot this.

The evening sky also has its attractions. Venus will be prominent, low in the western sky in April twilights, and on the 3rd and 4th of April, the constellation of Pleiades, or the Seven Sisters, will appear to become an octet as Venus passes through. Look for this immediately after sunset. Venus is so bright that it can be seen in daylight – although this is difficult if you don’t know where to look.

Speaking of the daytime skies, don’t look at the Sun! (even with sunglasses) – but we must mention that it is currently going through a major upheaval as its South and North Magnetic Poles change places. This sounds alarming, but happens regularly about every 11 years, and is part of a cycle related to sunspot activity. This solar magnetic activity has been observed through 24 such cycles, but the mechanics of it are still poorly understood. However, as it affects the Earth’s ‘space weather’, radio transmissions, the amount of UV radiation reaching the Earth and possibly terrestrial weather and climate, it is a vital area of study. The Parker Solar Probe, orbiting well within Mercury’s orbit, will continue to gather information on this subject over several years.

In Australia, the autumn equinox is on March 20. Not only are day and night of equal length, but the equinoxes are the only days when the Sun rises exactly in the east and sets exactly in the west. For the other days of the year, this cannot be said to be strictly true.

(Note: stated times are in Australian Eastern Standard Time, not Australian Eastern Daylight Time – add an hour for daylight saving, i.e., up to 5th of April)