SUPERMOON SATURDAY - SUNDAY

Irish Astronomical Association MEDIA RELEASE

 

Supermoon on Saturday evening & Sunday morning: 

 

Look out for a bigger, brighter, Full Moon, this weekend!

 

The Full Moon on 6 May will happen at the time when the Moon is at its closest to the Earth all year. This means that it will appear particularly big and bright in the sky - up to 30% brighter than some other Full Moons this year. The increase in apparent size won't be quite so noticeable - it will be 14% bigger than some of the other Full Moons this year.

 

It's all due to the Moon's elliptical orbit around the Earth, which means that its distance from us is constantly varying. Closest approach to Earth is called 'perigee', and due to various other factors, some perigees are closer than others. And it so happens that the closest lunar perigee of 2012 coincides very closely with the Full Moon on May 6. In fact, Full Moon will be at 04.35, and the perigee will be at 04.33, BST. The distance of the Moon then will be 356,955 km, compared with the mean distance of 384,400 km. That's 27,445km closer than average. 

 

Thus the Full Moon will appear noticeably bigger and brighter than usual on May 5 - 6. The effect will probably be most noticeable at moonrise and moonset, because of the so-called Moon Illusion, which makes the Moon appear bigger when it is close to the horizon.

 

So have a look at Moonrise in the SE on the evening of Saturday 5th at about 8.45 p.m., and if you are up early, at Moonset on Sunday morning at about 05.20 in the SW.

 

 

NOTES TO EDITORS:

 

1. The Irish Astronomical Association is a registered charity dedicated to promoting interest in, and information about, astronomy and space and related topics. It is the oldest and largest astronomical society based in N. Ireland, and the largest amateur astronomy society in Ireland.

 

2. The Moon's orbit has an 'eccentricity' of 5.5% - in effect this is the amount by which it is an ellipse rather than a circle.

 

3. There is a lunar perigee every month, but it is rare for that to coincide with the Full Moon, and very rare for such a close perigee to coincide almost exactly (within 2 minutes) of Full Moon.

 

4. The next lunar perigee to be closer than this one won't be until 2014 Jan 14 (distance 356,923 km), but that will happen at New Moon, and so won't be visible.

 

4.  The Moon Illusion is a well-known odd effect whereby the Moon, particularly the Full Moon, always appears much larger when it is close to the horizon, i.e. rising or setting. It is a purely psychological effect, but it is a very strong one, and is not fully understood.

 

5. The IAA runs public events throughout the year, including free public lectures at QUB, and public outreach events in various locations throughout Northern Ireland, details of which are available on the website: www.irishastro.org and http://www.bbc.co.uk/thingstodo 

 

Contact:

 

Terry Moseley

PR Officer,

Irish Astronomical Association