[an error occurred while processing this directive]
BBC News
watch One-Minute World News
Last Updated: Thursday, 23 June, 2005, 12:21 GMT 13:21 UK
June Moon dazzles skywatchers
Moon over St Petersburg, Russia     Image: AP
Skygazers from St Petersburg (pictured) to the UK could see the effect
Observers were treated to a spectacular show in the evening sky last night when the full moon appeared bigger than it has done for several years.

The effect is down to an optical illusion that means a full Moon close to the horizon appears much larger than when it is high in the sky.

It coincides with the summer solstice, when the Sun is highest in the northern sky and the Moon is very low.

This, and other factors, conspired to make the Moon seem exceptionally big.

During midsummer, at the time of the solstice, the Sun sails as high as is possible across the sky during daytime, while the Moon skims low over the horizon.

Another factor is that the Moon's orbit around the Earth is known to wobble slightly. An 18.6-year cycle in this wobble took the Moon even lower in the night sky than usual for this time of year.

Peter Bond of the Royal Astronomical Society told the Daily Mail newspaper there was an easy way of demonstrating that the effect was just an optical illusion.

"If you hold a coin at arm's length, you can compare it with the size of the Moon and you will find that the Moon stays resolutely the same size in relation to the coin whether it is low or high in the sky," he said.




SEE ALSO:
Priceless Moon samples on display
26 Feb 05 |  Southern Counties
Europe probe arrives at the Moon
16 Nov 04 |  Science/Nature
Noah's Ark plan from top Moon man
08 Sep 04 |  Science/Nature


RELATED INTERNET LINKS:
The BBC is not responsible for the content of external internet sites


PRODUCTS AND SERVICES

News Front Page | Africa | Americas | Asia-Pacific | Europe | Middle East | South Asia
UK | Business | Entertainment | Science/Nature | Technology | Health
Have Your Say | In Pictures | Week at a Glance | Country Profiles | In Depth | Programmes
Americas Africa Europe Middle East South Asia Asia Pacific