Monday, February 15, 1999 Published at 15:06 GMT
Haloes hang over South Pole
The halo and 'sun dogs' seen above the pole
By BBC News Online Science Editor Dr David Whitehouse
Scientists at the South Pole research base were dazzled recently by one of nature's most enchanting sights - sky haloes.
The ice crystals alter the direction of the sunlight, or moonlight, passing through.
Different-shaped ice crystals alter the light's direction by differing amounts. In this way a 22 degree and/or a 46 degree halo can be formed.
Also seen in the photographs are parhelia or 'sun dogs.' These are patches of light on either side of the halo.
The South Pole is a good place to see them. Two of the three existing record halo displays were also sighted there in 1986 and 1990.