The Sky Above You – September 2021

By Duncan Lunan

The Moon will be New on September 7th, and Full on September 21st, the day before the Autumn equinox.  The crescent Moon will be near Venus on the 10th .   On the 25th the waning Moon will be below the Pleiades, and to the left of the Hyades cluster and Aldebaran, the brightest star in Taurus, on the 26th

The planet Mercury is below Venus to the right, very low in the early evening sky, and at its greatest elongation from the Sun on the 14th.  The very thin crescent Moon is near Mercury on the 9th.   

Venus is low in the west, still near Spica in Virgo, setting at 8.30 pm.  Venus is to the left of the Moon and closest to it on the 9th.  Unusually, there were consecutive flybys of Venus on August 9th and 10th, by ESA’s Solar Observer and its BepiColombo Mercury spacecraft.  Both flybys were for course corrections, but it will be interesting to see what data they picked up.

Mars is behind the Sun, no longer visible and in conjunction with the Sun next month.  After its planned five test flights, the Ingenuity helicopter is now acting seriously as a scout for the Perseverance rover, and has completed its twelfth and longest flight checking out rough terrain ahead of them both. 

Jupiter is moving westward in Capricornus and sets around 4 am, passed by the Moon on September 17th and 18th.  Earth is still close to Jupiter’s equatorial plane and there will be more transits of its major moons across the face of the planet – details are in the September issue of Astronomy Now.  NASA’s Juno probe has passed the 10th anniverary of its launch, on August 5th,  2011.  The mission was to have ended in 2016 with very close approaches to the planet, but due to a problem with the propulsion system, it remains in orbit over Jupiter’s poles and is now making close passes of Jupiter’s large moons, with Europa next in its sights.  Juno now has a ‘go’ for at least 44 more orbits, extending the missions to 2025 at least.  

Saturn in mid-Capricornus, to the right of Jupiter, sets at 2.30 am, passed by the Moon on the 16th

Uranus in Aries rises at 9 pm. Uranus is near the Moon on the 24th.   

Neptune is in the sky all night, in Aquarius near the boundary with Pisces, and is at opposition, nearest the Earth and due south at midnight GMT, on September 14th.
Duncan Lunan’s most recent book, The Other Side of the Interface, was published by Other Side Books at the beginning of the year, and is available through Amazon or through bookshops, or from the publishers.  For details and for his other books see Duncan’s website,

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