On 27th July 2018 a total eclipse of the Moon will be visible from Africa, Europe and western Asia. As seen from Britain, the Moon will rise totally eclipsed in the south-east at about 9.00 p.m., appearing as a dim coppery globe directly above brilliant red Mars. The Moon will start to reappear at about 10.15 p.m. The eclipse will be the longest of the 21st Century, with totality lasting for 1 hour and 43 minutes. From start to finish, the Moon will take nearly 4 hours to cross the Earth's dark umbral shadow.

What is a total lunar eclipse? A lunar eclipse occurs when the Earth comes between the Moon and the Sun, causing the Earth's shadow to cover the Moon. According to NASA, the Moon often turns reddish during totality because the sunlight bending through the Earth's atmosphere during sunsets and sunrises is then reflected onto the Moon.


The Cardiff Astronomical Society (CAS) is a thriving society located in South East Wales. It has been in existence for over 40 years and is one of the largest amateur astronomical societies in the UK. CAS continues to provide a range of facilities for both Society members and the public at large including a varied programme of talks on Thursday evenings (except in August) at the Physics and Astronomy Department of Cardiff University. In addition, regular night sky (and occasional solar) observing sessions are held at the Society's own Observatory at Dyffryn Gardens.

Our members come from all walks of life and their knowledge of astronomy ranges from complete beginner to advanced. You don't need any specialist knowledge to join us and neither do you need to own a telescope or binoculars. It's also possible to try us out before joining!

More details about the Society and what it does are available here

We are keen to get more Society members on board to assist with the running of CAS events - please see here how you can Help Us

Upcoming CAS Events

  • Next Talk

Thursday, 6th September 2018 - "The Wonderful 20th Century - How Astronomy was Transformed" to be given by Dr Allan Chapman, Oxford University

From 7.30 p.m. till 9.30 p.m. (at the latest) at Cardiff University's School of Physics and Astronomy, Queen's Buildings, The Parade, Cardiff CF24 3AA venue for talks

  • Next Observing Session

Friday, 7th or Saturday, 8th September 2018 - please click here

See below a map of the night sky at 9.30 p.m. on 7th/8th September. Left click on it to enlarge it and it can then be printed off, if you wish!

  • Next Star Party

Friday, 7th September from 7.30 - 9.30 p.m. at Dyffryn Gardens - please click here

How you can support CAS when shopping online

If you chose to do so, every time you shop online via 'easyfundraising' at one of 3,300 retailers - see opposite - a donation will be made to the Society and it won't cost you a penny extra. It's really simple to get started but please click here for more information including an important tip.

Sign up for free with easyfundraising

Come and join some of the Society's 300-plus members at one of our talks or observing events.
We promise a warm and friendly welcome for all.
Only £15.00 per annum also means you can make use of our Library.

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