The Night Sky in August

Longer but warmer nights make August the preferred month for fair-weather astronomers. The August night sky is made all the more interesting by the presence of several meteor showers, the main one being the Perseids.


Moon
The New Moon is on the 10th and the next Full Moon occurs on the 24th.


Planets
Mercury: Appears very low in the western sky in the constellation of Leo, after dusk. Best viewed early in the month.
Venus: Also best early in the month, Venus is very bright at magnitude -4.2 and it exhibits a phase of around 50%.
Mars: Slowly fading from the evening sky and best viewd early in the month with Mercury and Venus.
Jupiter: The dominant sight in the August sky. Jupiter is visible through much of the night. At its highest point, in the southern sky, a small telescope should show its North Equatorial Belt and its Great Red Spot. The South Equatorial Belt is missing – something that happens every 3 to 15 years.
Saturn: Although its rings are beginning to open out, Saturn is being lost in the evening twilight.
Uranus: Worth trying to locate at the end of the month when Uranus lies within 2 degrees of Jupiter.
Neptune: Not easy to pick out.

    Look our for Jupiter's Great Red Spot and the reappearance of the SEB

Meteors
Like most meteor showers the Perseids can be traced to the orbit of a comet, in this case that of Swift-Tuttle. The meteors consist of dust-sized particles which burn up on entering the Earth’s atmosphere, at an altitude of 60 to 70 miles, as the Earth passes through the trail left by the comet.

Its consistently impressive display can be traced as far back as 36 AD when Chinese astronomers noted high numbers of meteors.

The Perseids are visible between July 23rd and August 22nd, but peak activity is expected on the night of the 12/13th August with around 100 meteors per hour (ZHR) although, realistically, you are likely to around 30 per hour between midnight and 0300 on the 13th. The Perseids peak lies close to the festival of St Lawrence on 10th August, hence them being referred to as the ‘tears of St Lawrence’.

The best way to observe them is to look towards the northeast after dark. They appear to originate from the constellation of Perseus, which at midnight lies just below the easily recognisable ‘W’ of Cassiopeia. The highest frequency of meteors is likely just before dawn.

On the night of Wednesday 18th, the Kappa Cygnid meteor shower reaches its peak. Whilst it cannot begin to rival the Perseids for ZHR, it does occasionally produce some slow-moving fireballs.