Astronomy afficianados applauded as they were plunged into darkness on Sunday as the moon passed in front of the sun in a brilliant "ring of fire" eclipse. Astronomers and enthusiasts in Argentina were among the first to see the so-called annular eclipse as it crossed South America shortly after 1200 GMT, on course for Africa.
Staring up through special telescopes, protective glasses or homemade cardboard pinhole devices, they watched the Sun all but disappear briefly as the Moon crossed its path.
The eclipse was to be most visible in a 100-kilometre band across Chile, Argentina, Angola, Zambia and the Democratic Republic of Congo. More than 100 stargazers gathered on Sunday morning in the southern city of Sarmiento, the point in Argentina where the eclipse was expected to be most visible.
"I have already seen six annular eclipses and each one was different," said Josep Masalles Roman, an enthusiast who came all the way from Barcelona in Spain. "This one is going to be very fine and it is possible that we will be able to clearly see Baily's Beads," a string of points of light produced as the sun's beams break through peaks on the moon's surface.
The spectacle will reach Angola south of the town of Benguela around 1515 GMT, then move to Zambia and DR Congo just before the Sun sets and the light show ends. An annular solar eclipse occurs when the Earth, Moon and Sun line up. But even when perfectly aligned, the Moon is too far from Earth to completely block out the Sun, creating instead the impression of a fiery ring.
Terry Moseley of the Irish Astronomical Associationwarned that viewers should not observe the eclipse with the naked eye. According to the Astronomical Society of Southern Africa(ASSA), the eclipse can be safely observed using a basic pinhole projector.
Punch a tiny hole in a piece of paper with a sharp pencil, hold it into the Sun, and project the image onto a second sheet. The gaps between tree leaves make for a similar effect onthe ground, says the ASSA website, calling this "the coolest and safest way to watch a solar eclipse".
"As about 90 per cent of the Sun is covered, you'll notice a distinct drop in temperature and brightness, and a change in the quality of the light which is hard to describe," Moseley told AFP.
Locals in the province of Chubut around Sarmiento said they noted changes in the height of the tide and animals acting unusually. Experts say that as the day darkens, birds and animals enter a night-time routine, thinking sunset is nigh. At the height of the eclipse the Moon is right in the middle of the Sun, leaving a perfect ring of light around theedge.