Planets on display
Saturn is best placed this month, while Venus reaches its brightest at magnitude -4.6
Even though it is quite faint and never gets very high in the sky, Saturn is still the planet best placed for observation this month. At magnitude 0.4 it is an easy naked-eye object, brighter than most of the stars in the sky, but its low altitude means it will appear fainter than that figure suggests. The planet is also embedded in the frothy star clouds of the Milky Way’s almost-central region, so there is less contrast between it and the sky behind it, further reducing its immediate visual impact.
Saturn is still lovely to look at this month and is visible from sunset through to the late evening hours. To the naked eye it will look like a gold-hued star low in the southern sky during twilight, shining just above and to the right of the famous ‘Teapot’ asterism formed by Sagittarius’ brightest stars. Binoculars will enhance its subtle warm colour, and if you have a small telescope you’ll be able to see the planet’s famous ring system wide open too, looking like a huge hula hoop thrown over the planet. The larger the telescope you look through, the more detail you will see within the rings; with enough magnification and a large enough aperture you will be able to see several dark gaps in the bright rings, and many of the planet’s extended family of moons too. With a large telescope you will also be able to see some features on the planet itself, such as its dark pole, cloud bands on its disc and even the ink-black shadow of the rings cast on its disc.
A pair of binoculars or a telescope will also show you some interesting and well-known deep-sky objects close to Saturn. This month Saturn is never farther than two degrees – just four Moon widths – away from M8, the Lagoon Nebula, a huge cloud of glowing gas divided by a striking dark dust lane. This is a region in space where stars are being born, and you will see it as a small misty patch to the lower right of Saturn. Just above M8 is M20, another starforming region known as the ‘Trifid Nebula’ because it is split into three distinct areas by its dust lanes. M20 is smaller and less obvious to the eye than M8, which is hardly surprising seeing as it is more than a thousand light years further away from us. Saturn will form an attractive triangle with both of these nebulae throughout the month.
This month Saturn will also have a very attractive close encounter with the Moon. On the evening of 17 September the two worlds will be just two degrees apart, with the waxing gibbous Moon shining to the upper left of Saturn, making a very attractive pairing low in the southern sky.