In preparation for tonight's lunar eclipse: What you need to know and where to see it

A total lunar eclipse occurs when the Earth enters the sun and the moon and covers the moon with its shadow. When that happens, the moon can turn red, giving it the nickname of a blood moon.

Total eclipses of the moon occur at the full moon when the sun, the Earth and the moon are aligned to form a line. The astronomical term for this type of alignment is syzygy, which comes from the Greek word to be paired.

The moon does not have its own light but shines because its surface reflects the sun's rays. The moon has no clean light – it shines because its surface reflects sunlight. During a total lunar eclipse, the Earth moves between the sun and the moon and cuts off the light supply of the moon. When that happens, the surface of the moon takes on a reddish glow instead of becoming completely dark.

The reason the moon takes on a reddish color throughout is a phenomenon called Rayleigh scattering – the same mechanism responsible for colorful sunrises and sunsets, and for the blue-looking sky.

The second total lunar eclipse of 2018 will be visible in large parts of Australia, Asia, Africa, Europe, and South America. The totality will last 103 minutes, making it the longest eclipse of the 21st century

Eclipse in Cork

18:14: The penumbral eclipse begins (when the moon moves in the weak part of the Shadow of the Earth). Below the horizon Not directly visible

7.24pm: The partial eclipse begins (when the Earth moves between the sun and the full moon, but they are not aligned precisely). Below the horizon Not directly visible.

8:30 pm: The total eclipse begins. Below the horizon Not directly visible.

21h21: Maximum eclipse. Below the horizon Not directly visible.

20h.22: Moonrise. Below the horizon Not directly visible.

21h26: Maximum in Cork. That's when the eclipse reaches its greatest magnitude while the entire moon is over the horizon in Cork. The true maximum can not be seen in Cork because the moon is then below the horizon. The board of timeanddate.com is reaching a climax or finding an unobstructed area with free view to the east / southeast for the best view.

22.13pm: The total eclipse ends. Moon close to the horizon, make sure to have free view to the southeast

11:19: End of the partial eclipse

12.28am: End of the penumbral eclipse.

Star Events

July 27: The observatory of CIT Blackrock Castle will host a series of free events to mark the eclipse, including observations of the moon and planets by telescope. Join us from 19:30 on Friday.

More info here

Aug 11: Hook Lighthouse organizes an evening of star gazing for the meteor shower of the Perseids. The most spectacular meteorite shower of the year takes place in Ireland every month of August, the Earth cutting in two the tail of the comets that are also orbiting the sun and the Perseid meteor showers have place.

On August 11, the Lighthouse Visitor Center will remain open late to provide visitors with a star-watching evening. Perseids are created when the Earth crosses the tail of Swift-Tuttle, a comet that takes 133 years to orbit the sun

Meteors are created when tiny particles of dust and debris enter the Earth's atmosphere at nearly 60km second creating a shock wave. They burn quickly in the atmosphere leaving the impression of a huge fireball. The lighthouse will remain open until 11 pm, offering hot chocolates and coffee snacks.

For more details, see here

This story first appeared in the Irish Examiner.