PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of lakes and icy mountains on an alien moon orbiting an Earth-like planet (top). Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of lakes and icy mountains on an alien moon orbiting a ringed Earth-like planet (top). Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of an Earth-like planet as seen from its moon. The planet's parent star is also seen at right. Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of an Earth-like planet as seen from its moon. The planet's parent star is also seen at right. Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of arid mountains on an alien moon orbiting an Earth-like planet (top). The planet's parent star is seen at lower right. Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of lakes and icy mountains on an alien moon orbiting a ringed Earth-like planet. The planet's parent star is also seen at top left. Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of lakes and icy mountains on an alien moon orbiting a ringed Earth-like planet. The planet's parent star is also seen at top left. Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of water and icy rocks on an alien moon orbiting a Jupiter-like gas giant planet (top). Another moon is seen close by at upper left.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of icy rocks on an alien moon orbiting a ringed Earth-like planet (top). Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of icy rocks on an alien moon orbiting a ringed Earth-like planet (top). Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien landscape. Computer artwork of lakes and mountains on an alien moon orbiting an Earth-like planet (top). Earth-like planets capable of supporting life are found only in a star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien planet and star. Computer artwork of an alien (extrasolar) gas giant planet orbiting its parent star. Numerous large gas giant planets have been discovered around other stars. Most of them are larger than Jupiter and orbit much closer to their parent star than any of the planets in our Solar System. They are known as hot Jupiters.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien planet and star. Computer artwork of an alien (extrasolar) gas giant planet orbiting its parent star. Numerous large gas giant planets have been discovered around other stars. Most of them are larger than Jupiter and orbit much closer to their parent star than any of the planets in our Solar System. They are known as hot Jupiters.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien planet and star. Computer artwork of an alien (extrasolar) gas giant planet orbiting its parent star. Numerous large gas giant planets have been discovered around other stars. Most of them are larger than Jupiter and orbit much closer to their parent star than any of the planets in our Solar System. They are known as hot Jupiters.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Alien planet and star. Computer artwork of an alien (extrasolar) gas giant planet and its moon orbiting their parent star. Numerous large gas giant planets have been discovered around other stars. Most of them are larger than Jupiter and orbit much closer to their parent star than any of the planets in our Solar System. They are known as hot Jupiters.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Colliding galaxies. Computer artwork of colliding galaxies seen from an alien planet. Collisions between galaxies are fairly common. The collision distorts the shape of both galaxies, often casting off streamers of stars. Despite the fact that the galaxies may pass through each other, collisions between actual stars are exceedingly rare. Also seen is an extrasolar gas giant planet (left). Gas giants are large planets that have a rocky or metallic core, but the majority of their mass is a mixture of gases.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Extrasolar planet Gliese 581c. Computer artwork of Gliese 581c (upper right) and its moon. This planet is one of three that orbit the star Gliese 581 (left). Another one of the planets is seen crossing the parent star. Gliese 581c is the most Earth-like alien planet yet discovered. It lies in the star's habitable zone, a region around a star where the surface temperature of a planet is suitable for liquid water. Gliese 581 lies about 20.5 light years from Earth in the constellation Libra.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Medical nanorobot. Computer artwork of a nanorobot with rod-shaped bacteria. Nanotechnology is an area of science concerned with producing mechanical entities on the scale of nanometres (billionths of a metre). It is hoped that robots of this size will one day have medical applications, such as being used at a cellular level to remove cancerous cells or to fight illness.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Medical nanorobot. Computer artwork of a nanorobot with rod-shaped bacteria. Nanotechnology is an area of science concerned with producing mechanical entities on the scale of nanometres (billionths of a metre). It is hoped that robots of this size will one day have medical applications, such as being used at a cellular level to remove cancerous cells or to fight illness.

PHOTO: EAST NEWS/SCIENCE PHOTO LIBRARY Medical nanorobot. Computer artwork of a nanorobot with rod-shaped bacteria. Nanotechnology is an area of science concerned with producing mechanical entities on the scale of nanometres (billionths of a metre). It is hoped that robots of this size will one day have medical applications, such as being used at a cellular level to remove cancerous cells or to fight illness.