Images Dated 30th August 2002

LM of human sperm fertilising an egg

Sperm fertilising egg. Light micrograph of a human egg with sperm at its surface attempting to penetrate and fertilise it. The large size of the rounded egg is seen in relation to the tiny sperm at upper frame. Around the egg is a thick zona pellucida layer. Women usually produce one egg (ovum) for fertilisation, whereas men release some 300 million sperm (spermatozoa) which travel with whiplash movements of their tail through the uterus to reach the egg. Only one sperm succeeds in penetrating the egg's wall and fertilises the egg by fusing with its nucleus. When this occurs, the egg membrane forms a barrier to other sperm. Magnification: x260 at 5x7cm size. x130 at 35mm size

© DR YORGOS NIKAS/SCIENCE PHOTO LIBRARY

Two Voyager 2 images of the planet Uranus

Voyager 2 images of Uranus taken on 17 January 1986, when the spacecraft was 9.1 million kilomet- res (5.7 million miles) from the planet. The left true-colour image was composed from a series taken with blue, green & orange filters. The darker shading corresponds to the day-night boundary. The blue-green colour results from absorption of red light by methane gas in Uranus's atmosphere. The right image uses false colour & contrast enhancement to bring out details in the polar region. A dark polar hood is visible surrounded by progressively lighter concentric bands. This might be due to a brown smog being arranged into bands by zonal motions of the upper atmosphere. NASA 5x4 photo number 86 HC 82

© NASA/SCIENCE PHOTO LIBRARY

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2002 Belgian Grand Prix - Friday Practice
Spa-Francorchamps, Belgium. 30th August 2002
World Copyright - LAT Photographic
ref: digital file only