Images Dated 17th January 2006

Nuclear-powered spacecraft, artwork

Nuclear-powered spacecraft at Ganymede, computer artwork. Ganymede is one of the moons of Jupiter. The spacecraft is powered by nuclear fusion, the same process that takes place in the Sun. This is a cleaner source of energy than nuclear fission, though it is thought it will take many years to develop controlled nuclear fusion reactors. Travel to the outer planets, which involves much greater distances and travel times than for travel to the inner planets and the Moon, will probably require nuclear fusion. The crew's living quarters are at right, away from the nuclear propulsion systems at left. This minimises the exposure of the crew to dangerous radiation from the nuclear reactor

© CARL GOODMAN/SCIENCE PHOTO LIBRARY

Comet Shoemaker-Levy 9, artwork

Comet Shoemaker-Levy 9. Computer artwork of a fragment of Comet Shoemaker-Levy 9 approaching Jupiter (top right). Debris forming the tail of the comet fragment is at right. The main part of the comet fragment (bright glow, upper right) is heading towards the dark side of Jupiter. The fragments of Comet Shoemaker-Levy 9 hit Jupiter in July 1994, in a series of massive explosions that were directly observed by the Galileo spacecraft as it headed towards Jupiter, and later by other probes and telescopes. The impacts increased our understanding of both Jupiter and comets. The atmospheric turbulence that was created by the impacts remained visible for months afterwards

© CARL GOODMAN/SCIENCE PHOTO LIBRARY

Amoxicillin antibiotic drug molecule

Amoxicillin antibiotic drug, molecular model. This is a moderate-spectrum beta-lactam antibiotic. These drugs work by inhibiting the synthesis of bacterial cell walls, mainly in Gram-positive bacteria. Vulnerable bacteria include Streptococcus and Staphylococcus, and some Gram- negative bacteria such as Neisseria and Escherichia coli. Some strains of previously- susceptible bacteria have developed resistance to amoxicillin, as they produce the enzyme beta- lactamase, which destroys the drug. Hence, it is usually taken with clavulanic acid, which blocks this enzyme, a preparation called co-amoxiclav. Atoms are colour-coded: carbon (cyan), nitrogen (dark blue), oxygen (red), sulphur (yellow) and hydrogen (white)

© DR TIM EVANS/SCIENCE PHOTO LIBRARY