ESA’s Rosetta will be the first mission to orbit and land on a comet, one of the icy bodies that travel throughout the Solar System and develop a characteristic tail when they approach the Sun. Rosetta is scheduled to be launched on-board an Ariane-5 rocket in January 2003 from Kourou, French Guiana. A decision on the launch date will be taken by Tuesday 14 January (see Arianespace press release N° 03/02 of 7 January 2003 or at http:www.arianespace.com).

The mission’s target is Comet Wi

A vast, but previously unknown structure has been discovered around our own Milky Way galaxy by an international team of astronomers. The announcement is being made at the American Astronomical Society’s meeting in Seattle, Washington, on behalf of Drs Annette Ferguson, Rodrigo Ibata, Mike Irwin, Geraint Lewis and Nial Tanvir. Their observations suggest that there is a giant ring of several hundred million stars surrounding the main disk of the Milky Way. Despite its size, the ring has not been

University of Colorado at Boulder researchers have found, ironically, that two pollutants – carbon dioxide and hydrocarbons emitted from agricultural forest trees – offset each other somewhat in mitigating air quality problems.

Carbon dioxide, believed by scientists to be a major factor in greenhouse warming, has been shown to reduce “agriforest” emissions of hydrocarbons that contribute to ground-based ozone pollution, according to CU-Boulder doctoral candidate Todd Rosenstiel of the envir

An Australian geologist has identified what could be the first ever active flow of fluids through gullies on Mars.

University of Melbourne geologist, Dr Nick Hoffman, identified recent gully and channel development near the polar regions of Mars from images taken by the Mars Global Surveyor spacecraft. But contrary to the majority of scientific opinion which suggests that such features were carved by liquid water, Hoffman says the flow is most likely frozen carbon dioxide.

This Chandra X-ray Observatory image of the supermassive black hole at the Milky Way’s center, a.k.a. Sagittarius A* or Sgr A*, was made from the longest X-ray exposure of that region to date. In addition to Sgr A* more than two thousand other X-ray sources were detected in the region, making this one of the richest fields ever observed.

During the two-week observation period, Sgr A* flared up in X-ray intensity half a dozen or more times. The cause of these outbursts is not understood

Scientists from Johns Hopkins and the University of Wisconsin have discovered that a protein called Sir2, which is found in nearly all living cells, has a new function that might help explain how calorie restriction can increase lifespans for some animals, the scientists say. Their report appeared in the Dec. 20 issue of Science.

A number of laboratories have shown that restricting total calorie intake extends the lifespans of organisms ranging from yeast to laboratory animals. Others have