It’s autumn and the Sun is now setting before 7pm which means more time for observing. This is exaggerated even more at the end of the month, when, on the 25th of October summer time ends and the clocks go back 1 hour.
October nights can get very chilly so it’s time to start taking out the heavy clothes again. Wrapping up and keeping warm can be the difference between enjoying a night’s astronomy and coming inside early.
Mars will be the main feature in the sky in October this year. The red planet reaches opposition on the 13th October. Opposition is when the Sun, Earth and planet make a line, as seen from above, where the Sun and planet are on opposite sides of the Earth. This is generally a good time to view the planet.
Interestingly this month will also have 2 full moons. One on the 1st October and on 31st October, meaning we will have a full moon on Halloween! The second full Moon in a month is traditionally known as the blue moon, although the Moon will not actually be blue.
Sun and Moon
|Date||Sunrise (Irish Time)||Sunset (Irish Time)|
Not visible this month.
September is a great month to spot Venus. The only catch is that you will have to stay up very late or get up very early. It rises about 4 hours before sunrise and will be extremely bright in the east. It will be unmistakable.
Mars is at opposition on 13th October and will dominate the sky through October. It will appear as a salmon – pink coloured star and will have already risen when the sky gets dark. It will start off in the east and move towards the west as the night goes on and will be very bright.
Jupiter remains in the sky in October but is low in the west as darkness falls. It will be close to Saturn and will be the brighter of the two.
Saturn is visible close to Jupiter, it will also be low in the west as darkness is falling. It will be the dimmer of the two stars.
Stars and Constellations
The above sky chart is for 23:00 on 15/09/2020. You can click on the chart to open a new tab and bring you to Heavens Above. On this website you can generate a custom chart for the time and date you wish. The spring constellations are gone and the winter constellation are appearing on the eastern horizon after sunset.
High overhead are Cepheus (the house), Cassiopeia (the queen), Andromeda and Pegasus (the flying horse). Andromeda is the location of the Andromeda galaxy which is the furthest object that can be seen with the naked eye. Although, you will need very dark skies to see it. Andromeda and the Milky way galaxy are headed for a collision and will collide in an estimated 4.5 billion years.
In the south at this time of year, is the constellation of Pisces (the fish) and Aquarius (the water bearer). Mars is also in this area of the sky. Over in the east we have the winter constellations rising. You will see Taurus (the bull) which has a distinctive “V” shape and beside it the Pleiades or M45.