Tornadic supercell thunderstorm
Tornadic supercell thunderstorm. Bolts of cloud- to-cloud lightning in a supercell thunderstorm at sunset. A tornado is seen forming at bottom centre. A supercell thunderstorm is a severe long- lived storm within which the wind speed and direction changes with height. This produces a strong rotating updraft of warm air, known as a mesocyclone, and a separate downdraft of cold air. Tornadoes may form in the mesocyclone, in which case the storm is classified as a tornadic supercell thunderstorm. The storms also produce torrential rain and hail. Photographed on 10 June 2004 in Red Cloud, Nebraska, USA.
© Chris Gullikson/Jim Reed Photography/Science Photo Library
Mauna Kea telescopes and Milky Way
Mauna Kea telescopes and Milky Way. Silhouetted against a sunset glow are the Subaru Telescope (far left), the Keck I and II telescopes (centre left and centre), and NASA's Infrared Telescope Facility (far right). These telescopes are located on the summit of the Mauna Kea volcano, on the Pacific island of Hawaii, USA. The starry band of the Milky Way and its scattered nebulae (dark areas) dominates the night sky.
© DAVID NUNUK/SCIENCE PHOTO LIBRARY
Penguin breeding colony research
Penguin breeding colony research, with researchers and photographers in the background. Located at St Andrews Bay, this is the largest breeding colony of king penguins (Aptenodytes patagonicus) on South Georgia. Recording tags attached to fledging juveniles transmit data by satellite. Studies here and at other king penguin colonies reveal the foraging patterns of these birds. This penguin is found in Antarctic and sub-Antarctic regions. It is a social animal, living and breeding in large colonies of thousands of individuals.
© CHARLOTTE MAIN/SCIENCE PHOTO LIBRARY