Travellers have relied on accurate timekeeping for navigation since the development of the marine chronometer in the eighteenth century. Galileo, Europe’s twenty-first century navigation system, also relies on clocks – but they are millions of times more accurate than those earlier timepieces.

The operational Galileo satellites will carry two types of clocks – passive hydrogen masers and rubidium atomic frequency standards.

"HD 149026b is simply the most exotic, bizarre planet. It’s pretty small, really dense, and now we find that it’s extremely hot."

Using Spitzer, NASA’s infrared space telescope,Joseph Harrington of the University of Central Florida. and his team observed the tiny planet disappear behind its star and reappear. Although the planet cannot be seen separately from the star, the dimming of the light that reached Spitzer told the scientists how much light the hot planet emits. From this they deduced the temperature on the side of the planet facing its star. The team’s findings were published online in Nature today.

Photo: NASA/JPL-Caltech.

ESA’s X-ray observatory XMM-Newton has revealed a new class of exploding stars – where the X-ray emission ‘lives fast and dies young’.

The identification of this particular class of explosions gives astronomers a valuable new constraint to help them model and understand stellar explosions.

XMM-Newton image of M 31. Credit: ESA

A plateau on Mars known as Home Plate shows evidence of long-past explosive volcanic activity, say scientists on NASA's Mars Exploration Rover mission. And data collected during the rover Spirit's initial pass across the 90-meter (295 feet) wide plateau also supports earlier findings indicating that water once existed at or beneath the planet's surface.

Using data from the SCIAMACHY instrument aboard ESA's environmental satellite Envisat, scientists have determined that the carbon monoxide hovering over Australia during the wildfire season largely originated from South American wildfires some 13 000 kilometres away.

Using SCIAMACHY, Annemieke Gloudemans from SRON Netherlands Institute for Space Research and her colleagues at Utrecht University, the Vrije Universiteit Amsterdam and the Netherlands Meteorological Institute (KNMI) witnessed large quantities of released carbon monoxide (CO) above the southern continents. They also saw increased concentrations of carbon monoxide above Central Australia, a desert region that is not prone to forest fires.

The brightest stellar explosion ever recorded may be a long-sought new type of supernova, according to observations by NASA's Chandra X-ray Observatory and ground-based optical telescopes. This discovery indicates that violent explosions of extremely massive stars were relatively common in the early universe, and that a similar explosion may be ready to go off in our own Galaxy.

Credit: Illustration: NASA/CXC/M.Weiss; X-ray: NASA/CXC/UC Berkeley/N.Smith et al.; IR: Lick/UC Berkeley/J.Bloom & C.Hansen

COROT has provided its first image of a giant planet orbiting another star and the first bit of ‘seismic’ information on a far away, Sun-like star- with unexpected accuracy.

The unanticipated level of accuracy of this raw data shows that COROT will be able to see rocky planets - perhaps even as small as Earth - and possibly provide an indication of their chemical composition.

This is an artist’s impression of a Jupiter-sized planet passing in front of its parent star.
Such events are called transits. When the planet transits the star, the star’s apparent brightness drops by a few percent for a short period.

Astronaut Walter M. "Wally" Schirra Jr., one of the original Mercury Seven astronauts and the only man to fly on all three of NASA's early space missions, has died at the age of 84, a NASA official confirmed Thursday.

Schirra, who commanded the first rendezvous of two spacecraft in orbit, died of natural causes, according to NASA.

"We have spoken with his family and we can confirm he did die of natural causes.

Chefs have long used a simple trick to differentiate between a raw and hard-boiled egg. By spinning an egg and watching how it behaves when the spin is disrupted, it's easy to tell whether its interior is solid or liquid.

Applying a similar test to the planet Mercury, astronomers have found strong evidence that the planet closest to the sun has a fluid core. The research, led by Jean-Luc Margot, assistant professor of astronomy at Cornell, appears this week on the Web site of the journal Science.

New observations by the NASA/ESA Hubble Space Telescope have overturned conventional ideas about the early life of some massive globular clusters, showing that they can go through several periods of intense stellar formation rather than the previously accepted single burst. The analysis of Hubble data from the massive globular cluster NGC 2808 provides evidence that star birth occurred over three generations early in the cluster's life.

This NASA/ESA Hubble Space Telescope image of a dense swarm of stars shows the central region of the globular cluster NGC 2808. Astronomers were surprised when Hubble spied three generations of cluster stars.