Limerick Astronomy Club - The June night sky

The month of June showcases the first of two solar eclipses this year. On June 10 the orbit of the Moon will pass in front of the Sun. However, due to the fact that the Moon will be at its furthest distance from the Sun (known as apogee), the Moon will not completely cover Sun, leaving an outer ring of the Sun visible.

This type of solar eclipse is known as an annular eclipse or ‘The Ring of Fire’. Unfortunately, unless you are in parts of Russia, Greenland or northern Canada, you won’t get to witness the annular eclipse but from Limerick you will experience a partial eclipse. Beginning at approximately 10am you will see the Moon start to pass in front of the Sun.

The partial eclipse will peak around 11am when approximately 30% of the Sun will be covered. In total the partial eclipse will last approximately two hours finishing just after noon. If you wish to view this event it is important to be prepared. Never look at the Sun during an eclipse as this could permanently damage your eyes. You can view the eclipse safely by projecting it onto a sheet of white paper or card using a very simple, and easy to make, pinhole projector.

You will notice that as the nights get longer, it is getting much later before we can observe even the brightest of stars. This is because for a period of weeks around the summer solstice the Sun is less than 18 degrees below the horizon and as such we don’t experience full darkness, only astronomical twilight. It is only when the Sun is more than 18 degrees below the horizon that full darkness is achieved. Nevertheless, there is still plenty to see in the night sky. In particular, you may be fortunate enough to witness a display of noctilucent clouds (NLC).

Resembling thin, wispy cirrus clouds, NLCs are only observed in the northern sky, close to the horizon and shine a highly distinctive iridescent bluish silver colour. They are the highest clouds in the atmosphere, generally occurring at altitudes of 80-85 km in a layer known as the mesosphere.

Because these icy clouds are so high, it means that they are illuminated by the Sun long after it has set providing the perfect observing conditions for us.

For more, email limerickastronomyclub@gmail.com