April Gallery

Keck I and II telescopes on Mauna Kea, Hawaii

Keck telescopes. Domes of the Keck I (at left) and Keck II optical telescopes seen at sunset at the Mauna Kea observatory in Hawaii, USA. The Orion constellation is seen above them in the sky. Each telescope has a 10 metre diameter mirror to focus light. The mirrors, made up of 36 hexagonal units, are mounted on computer-controlled motors that make tiny adjustments to keep astronomical objects in precise focus. The two telescopes can be used to observe the same object and can have their signals combined by interferometry to obtain a more accurate image. In 1997 the Keck telescopes are the largest optical telescopes in the world

© JOHN SANFORD/SCIENCE PHOTO LIBRARY

Particle tracks on geometric patterns

Particle tracks and geometrical patterns. Computer illustration of subatomic particle tracks (white & yellow) and geometrical patterns (pink) on a starfield. The tracks result from particles moving through a bubble chamber containing a superheated liquid. The disturbance of the liquid by the particles causes it to boil, so that tracks of minute bubbles are left in the wake of the particles which can be photographed and studied. Each particle has a distinct pattern, allowing it to be easily identified. Particle physics has revealed the basic structure of the atoms from which everything is made

© MEHAU KULYK/SCIENCE PHOTO LIBRARY