Weymouth Astronomy

The Planets - September 2020

Observing the planets can be extremely rewarding. Everyone remembers the first time they observed Saturn and it's rings or the gas giant Jupiter and it's Galillean Moons. Solar System


Mercury, the innermost planet is barely visible this month lying very low above the horizon to the east of the Sun at sunset.


Venus was at greatest elongation east on August 12th but still dominates the pre-dawn sky rising around three and a half hours before sunrise. In Gemini as September begins, it passes into Cancer on the 4th and Leo on the 23rd of the month.


This is the first of two great months to observe Mars which has its closest approach to Earth on October the 6th. Lying in Pisces, Mars can be seen towards the south-east at the start of the month rising at 9:45pm BST as September begins and 2 hours earlier by the months end.


Jupiter is now visible towards the south as darkness falls and crosses the meridian. Sadly, even when due south it will only have an elevation of 16 degrees above the horizon so the atmosphere will limit our views. On September 12 Jupiter ends its retrograde westwards motion and moves eastwards across the sky again.


Saturn following Jupiter into the sky (approx 8 degrees behind) and crosses the meridian at 10:18pm BST at the start of the month and at 20:19pm BST by the end and lies in Sagittarius near the border of Capricornus.

Information collated from Jodrell Bank and Astronomy Now magazine