Twin eclipses in May 2003
British skywatchers had a double treat with a total lunar eclipse followed two weeks later by an annular solar eclipse. Both these events were visible from the UK.
Total lunar eclipse
On 16 May 2003 astronomers watched a total eclipse of the Moon that finished just before sunrise.
Total lunar eclipses occur when the full Moon is exactly in line with the Earth and Sun and moves into the Earth's shadow. They can be seen wherever the Moon is above the horizon and so from a given spot on the Earth's surface are much more common than solar eclipses, although they are still infrequent events.
This eclipse was visible from much of Western Europe (including the whole of the British Isles), western Africa and the eastern half of the Americas. From the UK the Moon sunk towards the south-west horizon as the eclipse progressed.
The Moon will entered the lighter, penumbral shadow of the Earth at 02.05 BST. At 03.03 BST the Moon entered the darker, umbral shadow. The shadow of the Earth then appeared to steadily move across the Moon until it was totally eclipsed by 04.13 BST. Totality lasted until 05.06 BST and from London the Moon set at 05.17 BST. Below the horizon from the UK, the Moon will left the umbra at 06.17 BST and finally the penumbra at 07.15 BST when the eclipse ended.
During the total eclipse the Moon darkened considerably but did not disappear. Unlike solar eclipses, it is perfectly safe to look at the Moon before, during and after a lunar eclipse and everyone is encouraged to do so!
Annular solar eclipse
Just two weeks later an annular eclipse of the Sun is visible at sunrise from northern Scotland.
Like total solar eclipses these are only seen at new Moon and when the Earth, Moon and Sun are exactly in line so only happen every 18 months or so. In an annular eclipse the Moon is too far away to completely cover the Sun and a bright ring of sunlight remains around the lunar silhouette.
Annular eclipses are rare – the last one in the UK was seen back in 1921 and the next one will be in 2093. This month annularity is visible from much of northern Scotland including the Hebrides, Orkney and Shetland islands. The rest of the UK will see a less spectacular partial eclipse.
The annular phase of the eclipse begins shortly after sunrise on 31 May when the Sun will appear as a spectacular deep red 'ring of fire' with a dark centre. From Kirkwall sunrise is at 04.13 BST when the partial eclipse will already be well under way and the Sun will appear to have a large 'bite' taken from it. Annularity begins at 04.46 BST and ends just 1 minute and 40 seconds later. The Moon then slowly reveals more of the Sun, which appears to grow in size until the eclipse ends at 05.45 BST.
Observers should not attempt to view the solar eclipse directly. Although the Sun will be very low in the sky and will appear relatively dim, looking directly at it with a telescope or the unaided eye is extremely dangerous and can lead to permanent eye damage or even blindness. The safest method of observation is to use a pinhole projector or eclipse filters purchased from reputable astronomical suppliers.
