If you would like to become familiar with the night sky, go outside, settle down, and dress reasonably warmly - August is still in winter so it can get cold at night. Make sure you’re familiar with the cardinal directions - east, west, north, south - and also, do have a sky map, possibly downloaded from the Sydney Observatory blog, www.sydneyobservatory.com/blog.

Then you’ll need a torch with a bit of red taped in front of it. You can attach a bit of red tissue paper, or red cellophane, in front of the torch to give you red light, because red light does not destroy your adaptation to the dark. You can attach it with a rubber band.

What I would like to do is tell you about what you can see if you go outside on, basically, any night during the month. At the end of the podcast, I will tell you about a major astronomical event this month, which is a total eclipse of the Moon. And this is the first one for quite a number of years that’s happening at a convenient time in the evening, and it’s a very spectacular event. I’ll come back to that at the end of this guide.

So if you look directly upwards, you will see the constellation of Scorpius, the Scorpion. This is one of the most easily recognisable constellations in the sky, and it’s one of the main features of the Australian winter sky. It’s a curved group of bright stars, and it’s one of the few constellations, or star pictures, in the sky that actually doesn’t look too far from what its name is. Scorpius means scorpion, and - with a little bit of imagination - it does look like a scorpion.

In the northern sky, we have the claws of the scorpion, and in the southern part, we can see the actual tail of the scorpion. One of the stars at the end of the tail is known as Shaula, which, in Arabic, means ‘to sting’. And that does represent the position of the star in the curved tail of Scorpius.

There’s also the bright star Antares, which represents the heart of the scorpion. And very appropriately, Antares is a reddish star, one of the few stars in the sky of which the colour is obvious. And it is reddish because it’s a fairly cool star. It’s a giant star which is bloated near the end of its life cycle, but its outer surface, as it expanded and became larger, cooled down.

And it’s relatively cool, cooler than the surface of our own Sun; hence, it has this reddish colour. Its name means ‘the rival of Mars’, which is because it has a similar red colour to the planet Mars. The planet Mars can, on occasion, from our vantage point on earth, appear to move past Antares, very close to Antares, and then the similarity between the two objects, between the red planet Mars and the red star Antares, is very striking.

Antares is also very large; as I said, it’s a giant star. If it was placed instead of our own Sun, it would be so large that it would engulf the Earth, and not only the Earth, but also the planet Mars. And, of course, this will happen also to our own Sun in the end of its life cycle - hopefully, not for another five thousand million years. But at that period, it will expand and become a red giant similar to Antares.

Now just below Antares, or a little bit towards the east of Antares, is the planet Jupiter, which is a very bright whitish colour, quite unmistakable. Through a small telescope, we can see the banding of the planet, and we can see its four small Galilean moons. The actual number of Jupiter’s moons is something like 63 moons, but the four brightest ones, the Galilean moons, are what we can pick up with a small telescope.

You can even see them with a pair of binoculars, but the trick with binoculars is to hold them very steady. And normally, if you hand-hold a pair of binoculars, there’s a little bit too much shaking to be able to see such delicate features as the four little moons surrounding Jupiter. But if you can place binoculars on a tripod, or some other way that’s very firmly supported, then you have a good chance of actually, even through a pair of binoculars, seeing those four little moons.

Let’s go over to the eastern part of the sky. There, fairly prominent, is the constellation of Sagittarius, the Archer. The stars are not as bright as the stars of Scorpius, but they’re just below Scorpius, so they’re not difficult to find due east.

They’re also known to many people as the Teapot. So instead of Sagittarius, the Archer, those stars are known as the Teapot. The four stars below represent the handle, then the star to the left, or north, represents the lid of the teapot, and above are the stars forming the spout of the teapot. Quite unmistakable, once you pick it out the first time.

To the left, or north, and a little bit below Sagittarius, we find the constellation of Aquila, the Eagle. And that constellation, that group of stars, is easily recognisable through the bright star Altair, and that’s a nice bright star. It’s a star known because it spins very fast. In fact, some rather complex telescopic observations have indicated that its shape is not spherical, but it’s elongated. And it’s elongated because it’s spinning so fast.

If we go over to the northern part of the sky, then we can see this constellation of Bootes the Herdsman. And that contains the star Arcturus, which is known as the Bear Guard; the name comes from an Arabic phrase meaning ‘the Bear Guard’. And that’s a slightly reddish star.

Below Arcturus and to its right - over to the east, further on down -we find the constellation of Lyra, which means the musical instrument, the lyre, and according to Greek legend, it is the lyre given by the sun god Apollo to the musician Orpheus.

The star Vega, which is the brightest star in Lyra, is a very well-known northern hemisphere star. And being in the southern hemisphere, we do not see it very often. But in August, September, this time of the year, we get a chance to see this very well-known star for astronomers in the northern hemisphere.

Let’s go over to the west, and there, very prominent, due west, below Scorpius, we find the star Spica, and that’s the brightest star in the constellation of Virgo, the Maiden. One way of finding Spica is to look in the western sky for a group of four stars forming a somewhat distorted rectangle, and that’s the constellation of Corvus, the Crow. And two of the stars of Corvus point upwards to the star Spica. As I said, that is the brightest star in the constellation of Virgo, the Maiden.

Now, let us go to the final quadrant, final part of the sky, and that is the south. And there, of course, we find the Southern Cross, known to astronomers as Crux. So you find that on lots of star maps; you find it written as Crux. In August, in the early evening, the Southern Cross is a little at an angle from being upright. If you think of the Southern Cross representing the hour hand of a clock, it is in the one o’clock position. And it’s easily recognisable as a compact group of stars.

Pointing to it are the two pointer stars, and these are a little bit above and towards the left, or towards the east. The nearest of the pointers is Beta Centauri. And a little bit further away, a little bit further from the cross, is Alpha Centauri, the triple star system. It represents the closest star system to our own sun, and light from Alpha Centauri takes four and one-third years to reach the Earth.

Surrounding the cross is the constellation of Centaurus the Centaur, and that surrounds it on three sides. And of course, the two pointer stars, Alpha and Beta Centauri are part of the constellation of Centaurus the Centaur.

This completes the guide of what we can see in the night sky in August. But as I said at the beginning of this podcast, I would like to tell you about a major astronomical event happening this month, and that is a total eclipse of the Moon. That takes place on the evening of Tuesday, the 28th of August. And that is a total eclipse of the Moon; that is when the Moon moves into the Earth’s shadow.

One of the spectacular parts of an eclipse of the Moon is that the Moon does not become completely dark when it moves into the Earth’s shadow, but it takes on a dark, reddish colour. And this is light scattered from the Earth’s atmosphere onto the Moon.

So it’s sunlight that goes through the Earth’s atmosphere; the blue is removed by it being scattered in all directions, and what is left is the red light, and that is scattered onto the Moon and we see the Moon take on this reddish colour.

The eclipse will start on the 28th of August at 6:51pm Eastern Standard Time, and the Moon will be fully immersed in the Earth’s shadow at 7:52pm. In the next hour and 31 minutes, the Moon will be moving through the Earth’s shadow, and it will be totally eclipsed, and we should see this dark, reddish colour.

Exactly how dark and how reddish the Moon will turn is something we only find out on the actual event itself, because how dark it turns depends on the conditions in the Earth’s atmosphere. So if there’s lots of dust, it might be rather faint and the redness may not be that obvious. Totality finishes at 9:23pm, when the Moon starts moving out of the Earth’s shadow, and it will move completely out of the Earth’s shadow at 10:24pm.

For people in the eastern states, the whole eclipse is visible. For people in western Australia, the eclipse will start with the Moon rising while it’s partially eclipsed.

This completes the guide to the night sky in August of 2007. This comes from the Sydney Observatory Blog, www.sydneyobservatory.com/blog. The information on which it is based comes from the ‘2007 Australia Sky Guide’, which is published by Powerhouse Publishing. It’s available through good book shops, or directly from the Powerhouse Museum.

Source: Sydney Observatory

An airoplane passing by. All photos by Puls Polonii