December Gallery

Red dwarf star

Red dwarf star. Artwork representing the intense activity of a red dwarf star. These are among the least massive stars in the universe ranging from 0.1 to 0.7 solar masses. The star shown here belongs to a subclass of red dwarf stars, known as the flare stars, which are characterised by frequent (3-4 per hour) flares. These are seen as sudden brightenings with a typical rising time between 1s and 1min and a slower fading time between 1min and 1 hour. During a flare, filaments of gas in the atmosphere are accelerated outwards with speeds up to 1000km/s. Such speeds are greater than the escape velocity and therefore the matter ejected will be lost from the parent star

© JULIAN BAUM/SCIENCE PHOTO LIBRARY

Us-Space-Earth-Moon

This 16 December, 1992 NASA file image captured 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near- infrared filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. AFP PHOTO/ NASA / AFP PHOTO / NASA / NASA

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