October 2021 Skies

October 2021 Skies

October Skies

Spring is here! Spring brings out the wildflowers and some new things to see in the amazing sky! Scorpius and Sagittarius slowly leave our night skies to be replaced by Orion and its nebulae, and bright star Sirius. The Southern Cross will be low on the southern horizon before rising again in summer and we can only see the head of the Emu as the brightest part of the Milky Way fades until next March. But the Magellanic clouds (two galaxies orbiting our own Milky Way) will be visible in the South. To find these two galaxies – you will need a dark sky. So face due south, and let your eyes travel up from the Southern Cross towards the only bright star high above in the south (Achernar),  you should then be able to spot a cloudy patch of light and just below that you will see a slightly bigger cloudy patch.

The Indigenous people of the Adelaide plains saw them as ashes of two celestial parrots sneakily killed and eaten. To the peoples of the lower Murray the bright patches are two brolgas escaping the celestial Emu. In some stories, the brolgas act as guides for lost humans. Some stories have them as the campfires of an elderly couple. The Gundidjmara people in Victoria see the larger cloud as a ‘gigantic crane’, the smaller cloud being the female equivalent. A similar version isalso been recorded by the Kamilaroi people here in North West NSW. As with their terrestrial counterparts, these celestial spirit beings migrated according to the season. In the winter sky, the cranes are seen lying to the southeast and then south of the Milky Way. In summer they shift towards the western side

 It can still get cold at night, so don’t forget to rug up before heading out.

Also don’t forget Daylight Saving starts in New South Wales, Victoria, South Australia, Tasmania, the Australian Capital Territory and Norfolk Island on October 3rd and clocks go forward and hour so all times this month are in AEDT (Australian Eastern Daylight Time)

However, for now, let’s think about what is in the sky this month.

The Moon this Month

(All times are in Australian Eastern Daylight Time)

New Moon:                    10:05 pm October 6th

First Quarter:                 02:25 pm October 13th

Full Moon:                      01:56 am October 21st

Last quarter:                  07:05 am October 29th

At 2am on October 9th the Moon will be at Perigee which is the closest it gets to the Earth each month. This Month is will be a mere 363,386km away. On the 24/25th  at midnight the Moon will be at apogee its furthest point from Earth this month at 405,615 km.

Figure 1: early evening sky on 8 October at 8pm AEDT showing Venues with a tiny crescent Moon from Stellarium

Planets in October

This months fun fact about the planets:

Did you know? Wind speeds on Neptune are among the fastest recorded in the Solar System. Some may reach up to 2,160 km per hour.  They are five times stronger than the strongest winds on Earth. The winds on Saturn are the second-fastest.

Mercury begins the month slightly to the south of the bright star Spica in the western evening twilight. Spica is the brightest star in the constellation of Virgo. It then quickly descends toward the Sun and inferior conjunction when it will be between the Earth and the Sun the 10th making it impossible for us to see until it returns to the early morning sky when it will be hard to spot just above the eastern horizon on the 25th before sunrise.

Venus, shining brilliantly in the western evening sky and you certainly can’t miss it.  Venus will be in the constellation of Libra for the first week of October before moving into Scorpius and finally into Ophiuchus. On the 9th and 10th, it will very close to the Delta (δ) Scorpii which is the middle star of the three-star line that makes up the claw region of the Scorpion. A nice colour contrast will be seen on the 16th and 17th when Venus appears very close to Antares (Alpha (α) Scorpii). Antares is the brightest star of the constellation and distinctly reddish and is known as the heart of the Scorpion.

Figure 2: Venus and Antares looking west on 15 October at 8.34pm AEDT

Mars is in conjunction with the Sun on the 8th and will not be visible until its reappearance in the morning sky during late November in Libra.

Jupiter is in a perfect position for observing this month, appearing high in the early north-western evening sky. On the 15th, the 10-day old waxing gibbous Moon pretty close to Jupiter (see Figure 3). Jupiter has been in Capricorn since August now on the 18th it will appear stationary as it comes to the end of four months of retrograde motion. It will then  resume its west to east motion across the sky and head back towards Aquarius.

Figure 3: Jupiter, Saturn and the Moon on 15 October

Saturn is ideally located in the early north-western evening sky for observing. It will appear stationary on the 11th as it comes to the end of its west to east motion across the sky. On the 30th the planet is at a point in its orbit known as eastern quadrature. This is where the Sun-Earth -Saturn angle is 90°. At this time as the Sun sets in the west Saturn will be at its highest altitude in the sky. It is also a favourable time to view the maximum shadow of the planet’s globe cast onto the rings giving Saturn a 3-D appearance. On the 14th, the 9-day old waxing gibbous Moon appears around 4° from the planet.

With opposition early in November, Uranus rises in the eastern sky soon after sunset, situated in a barren part of Aries the Ram, near the head region of Cetus the sea monster or near the tail of Cetus the whale.

Now past opposition, Neptune transits the meridian (is due north) around 10PM mid-month Aquarius.

Figure 4: The planets can be categorised into three groups – the gas giants; the ice giants; and the terrestrial planets
Figure 5: Morning sky on 25 October at 2.25am AEDT

Meteor Showers

The Southern Taurids are active from 10 September through to 20 November. The shower is composed of two radiant nearly equal activity ten degrees apart. The Southern Taurids peak with about 5 meteors per hour around 10 October and the Northern Taurids next month on the 12th. The Taurids are frequently bright, sloe moving and noted for occasionally producing colourful fireballs. They are associated with Comet 2P/Encke and can be seen from late evening to early morning.

At their peak, the waxing crescent Moon sets late evening leaving the morning sky Moon Free.

Southern Taurids

The Southern Taurids are a long-lasting shower that several minor peaks during its activity period. They are active from 10 September through to 20 November. The shower is composed of two radiants with nearly equal activity ten degrees apart. The Southern Taurids peak with about 5 meteors per hour around 10 October and the Northern Taurids next month on the 12th.

The Taurids are frequently bright, slow moving and noted for occasionally producing colourful fireballs. They are associated with Comet 2P/Encke and can be seen from late evening to early morning.

At their peak, the waxing crescent Moon sets late evening leaving the morning sky moon free and worth the effort of an early morning session.

Southern and Northern Taurids

Orionids

Next period of activity: October 2, 2021, to November 7, 2021

The Orionids are best seen from late evening until dawn and are visible from 2 October through to 7 November. Maximum activity is expected around the evening of the 21st through to the morning of the 22nd. Over the past twenty years or so the Orionids have produced rates around 20 meteors per hour. They are a medium strength shower that sometimes reaches high strength activity. In a normal year the Orionids produce 10-20 shower members at maximum. In exceptional years, such as 2006-2009, the peak rates were on par with the Perseids (50-75 per hour). Recent displays have produced low to average displays of this shower. With many sub-maxima, good rates can be observed on several consecutive nights around this date although the Full Moon on the 21st will hamper observation this year. The Orionids are typically very swift and often bright, with some leaving trains. The shower was first recorded by Chinese observers in 288 CE and is associated with Halley’s Comet.

Looking for Christmas Gift Ideas?

Why not grab the 2022 Astronomy calendar which also includes the amazing photos and information on the planets, moon phases and sky maps for each month –$19.95

Want to get the best information for what is in the sky each month grab your copy of Astronomy 2022 Australia also on special this month from our website. Only $29.90 for a year full of amazing information on what you can see in the sky – even without a telescope.

Clear skies until next month! Stay up to date on my Facebook page.

Donna

Donna the Astronomer

I am a keen astronomer lucky enough to live and work in Coonabarabran the Astronomy Capital of Australia! I am a ‘Drover’s Brat’ and discoverer of a couple of comets and asteroids. I operate Milroy Observatory and can show you how to best integrate dark sky experiences into your tourism, farm stay or AirBnB business.

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