Neptune Gallery

Voyager 2 image of Neptune

Voyager 2 spacecraft image of the planet Neptune, reconstructed from two images taken through green & clear filters by Voyager's narrow- angle camera. Voyager passed within 5, 000 km of Neptune during August 1989. Towards the north (top of image) is the Great Dark Spot, a giant cloud system that is accompanied by bright, white clouds which undergo rapid changes in appearance. To the south of the Great Dark Spot is a solitary white feature, the so-called "scooter". Further to the south is a smaller dark spot with a bright, white centre. Strong eastward winds cause the smaller, faster moving dark spot to overtake the Great Dark Spot every five days

© Nasa/Science Photo Library

Venus transiting the Sun, telescope image

Gliese 436b is a mid-sized exoplanet roughly the size of Neptune in our own Solar System. It orbits its parent star, the red dwarf Gliese 436, at an extremely close-in distance of just 0.03 astronomical units, taking 2.64 days to go around once. By contrast, Mercury orbits at more than 10 times this distance from the Sun and takes 88 days. Gliese 436b was found using the transit method of discovery, whereby the planet -- as seen from the Earth -- passes first in front of and then behind its parent star. During these events, called transits, the brightness of the system is modulated, enabling astronomers to infer the presence of a planet and calculate its orbital period and mass using the laws of motion

© DAVID NUNUK/SCIENCE PHOTO LIBRARY

Solar system, 1893

Solar system. Diagram of the solar system, based on the astronomical knowledge at the end of the 19th century. The Sun is at centre. The orbits of the planets out to Saturn are shown, as well as the asteroid belt (marked insminor planets) between Mars and Jupiter. The orbits of two comets are also shown, as well as the moons and rings of Jupiter and Saturn. The planetary orbits are to scale, though the orbits of the moons are not to scale. Two other planets had been discovered by this time (Uranus and Neptune), but are not shown. Halley's comet was identified as periodic in the 17th century. Faye's comet had been discovered more recently, in 1843. Artwork from Pioneers of Science (Oliver Lodge, 1893)

© SHEILA TERRY/SCIENCE PHOTO LIBRARY