Atmosphere Gallery

Global water and air volume

Global water and air volume. Conceptual computer artwork of the total volume of water on Earth (left) and of air in the Earth's atmosphere (right) shown as spheres (blue and pink). The spheres show how finite water and air supplies are. The water sphere measures 1390 kilometres across and has a volume of 1.4 billion cubic kilometres. This includes all the water in the oceans, seas, ice caps, lakes and rivers as well as ground water, and that in the atmosphere. The air sphere measures 1999 kilometres across and weighs 5140 trillion tonnes. As the atmosphere extends from Earth it becomes less dense. Half of the air lies within the first 5 kilometres of the atmosphere

© Adam Nieman/Science Photo Library

Io and Jupiter, Cassini image

Io and Jupiter, Cassini image. Io, the round object at left, is one of the largest of the moons of Jupiter. Clouds in Jupiter's atmosphere form the backdrop to this image. Io has a diameter of 3642 kilometres, but Jupiter, the solar system's largest planet, dwarfs its moon, with a diameter of 142, 984 kilometres. Io is the innermost of the four Galilean moons, orbiting Jupiter at a distance of 350, 000 kilometres from its cloudtops. Image obtained on 1 January 2001 by Cassini's Imaging Science Subsystem (ISS)

© NASA/JPL/UNIVERSITY OF ARIZONA/SCIENCE PHOTO LIBRARY

Aurora borealis and Moon

Aurora borealis and Moon over mountains and trees by a river. This coloured light display (the northern lights) is visible in the night sky at high latitudes. It occurs when charged and energetic particles from the Sun (the solar wind) are drawn by Earth's magnetic field to the polar regions. Hundreds of kilometres up, they collide with gas molecules and atoms, causing them to emit light. Photographed by the Koyukuk River, near Wiseman, Alaska, USA

© CHRIS MADELEY/SCIENCE PHOTO LIBRARY