Space physicists from the University of Leicester are part of an international team that has identified the impact of the Sun on Mars' atmosphere.

Writing in the AGU journal Geophysics Research Letters, the scientists report that Mars is constantly losing part of its atmosphere to space.

The new study shows that pressure from solar wind pulses is a significant contributor to Mars's atmospheric escape.

The researchers analysed solar wind data and satellite observations that track the flux of heavy ions leaving Mars's atmosphere. The authors found that Mars's atmosphere does not drift away at a steady pace; instead, atmospheric escape occurs in bursts.

Anxiously awaited follow-up observations with NASA's Hubble Space Telescope have confirmed the presence of two new moons around the distant planet Pluto. The moons were first discovered by Hubble in May 2005, but the science team probed even deeper into the Pluto system last week to look for additional satellites and to characterize the orbits of the moons.

Though the team had little doubt the moons are real, they were happy to see the moons show up very close to the locations predicted from the earlier Hubble observations. The initial discovery is being reported today in this week's edition of the British science journal Nature.

For 1,400 years, a stash of Anglo-Saxon artefacts remained buried - until it was found last year by a man with a metal detector. It throws fascinating new light on clashes in the Dark Ages, but now we must win the fight to keep this precious hoard in Britain

It's a misty dawn in Middle England, some time in the 7th century. A small band of armed men struggle up a wooded hill. At the summit they pause. While one keeps watch, the others tip their loot on to the ground. They divide up the jewels and coins, then they turn to the rest of the booty: swords, crosses, saddle fittings, which are mostly gold and exquisitely made. They hammer at them with stones and the hilts of their knives, they rip the pommels from the swords and stuff the blades into their jerkins, smash the helmets and bend the arms of the crosses until they look like nothing more than twisted pieces of metal. They stuff the small gold and bejewelled fragments into leather pouches, grub out a hole in the earth, and bury their cache. Then they disappear over the hill as swiftly as they came.

Centuries pass: William the Conqueror's Normans arrive; the Tudors squabble over national control; Queen Victoria and the British Empire come and go. The hoard remains untouched - until 1,400 years later, when an amateur collector, Terry Herbert, rediscovers it on what is now a farm. Since Terry came across the treasure, now known as the Staffordshire Hoard, using a simple metal detector last July, the story behind it has captured the public imagination. The items he discovered - more than 1,500 pieces of beautifully crafted gold and silver - have been described as the most important Anglo-Saxon archeological evidence ever found in Britain. The battle to keep the bling in the country is well under way. The government would be unlikely to grant an export licence but it could still be split up and taken abroad illegally by a private collector. Despite all the furore, the hoard poses as many questions as it answers.

The DNA tests that revealed how the famed boy-king Tutankhamun most likely died solved another of ancient Egypt's enduring mysteries - the fate of controversial Pharaoh Akhenaten's mummy. The discovery could help fill out the picture of a fascinating era more than 3,300 years ago when Akhenaten embarked on history's first attempt at monotheism.

During his 17-year rule, Akhenaten sought to overturn more than a millennium of Egyptian religion and art to establish the worship of a single sun god. In the end, his bold experiment failed and he was eventually succeeded by his son, the young Tutankhamun, who rolled back his reforms and restored the old religion.

Researchers have uncovered the courses of ancient river systems under the Simpson Desert in Central Australia.

Professor Mike Hutchinson from the Australian National University says the systems are approximately 50 million years old and about 35 metres below the surface.

The regenerating liquid-metal robots in the Terminator movies have a cosmic relation: incoming asteroids that quickly reassemble if blasted by a nuclear bomb.

If a sizable asteroid is found heading towards Earth, one option is to nuke it. But too small a bomb would cause the fragments to fly apart only slowly, allowing them to clump together under their mutual gravity. Simulations now show this can happen in an alarmingly short time.

Don Korycansky of the University of California, Santa Cruz, and Catherine Plesko of the Los Alamos National Laboratory in New Mexico simulated blowing up asteroids 1 kilometre across. When the speed of dispersal was relatively low, it took only hours for the fragments to coalesce into a new rock.

A new study has shown that Arctic reindeer have abandoned use of the internal clock that drives the daily biological rhythms in other organisms, in order to live under extreme conditions in the Arctic.

"Our findings imply that evolution has come up with a means of switching off the cellular clockwork," said Andrew Loudon of the University of Manchester.

"Such daily clocks may be positively a hindrance in environments where there is no reliable light-dark cycle for much of the year," he added.

Light-dark cycles drive hormone rhythms via a circuit that involves the eye and nervous system projections to structures involved in regulating hormone rhythms, in particular melatonin, Loudon explained.

Photos newly released by NASA this February show the most detailed pictures of Pluto that have ever been taken. The Hubble telescope captured these images using its Advanced Camera for Surveys as recently as 2003. To put this in perspective, each picture is only a few pixels in size, and through computer analysis, the pictures were overlaid and enhanced to create a composite image of higher quality.

The significance of these pictures comes in comparisons. These new pictures were studied as part of a collection that included Hubble images from 1994, 2002 and 2003, as well as ground-based telescope images taken in 1988 and 2002. Among the changes observed over this time span are a doubling of the mass of Pluto's atmosphere, as well as a brightening of the North pole of the planet, and a darkening of the Southern hemisphere.

Pluto's surface has regions of different materials, resulting in the orange, white and black blotches of color. The atmosphere of Pluto is dynamic, resulting in this change in appearance. The increase in atmospheric mass is likely due to melting of nitrogen ice, which releases gas into the atmosphere.

Pluto's seasonal changes differ greatly from those on Earth. The eccentricity of Pluto's orbit makes it such that its seasons are not equal in length, since the planet accelerates as it gets closer to the sun. By comparison, Earth's orbit is relatively circular, resulting in seasons of equal length and intensity based on the tilt of Earth's axis.

One year on Pluto is equal to 248 Earth years, making each season on Pluto very long. Since its discovery, less than half a Pluto-year has elapsed.

In 1.5 million years time, the solar system could be in for a rough ride.

An orange dwarf star named Gliese 710 is powering in our direction and an astronomer has calculated an 86 percent chance of the interstellar interloper smashing through the Oort Cloud, located in the outermost reaches of our solar system.

This could have the devastating effect of scattering the icy Oort Cloud objects (or OCOs), causing them to plunge toward the sun and the inner planets, potentially bombarding Earth with comets.

Vadim Bobylev of the Pulkovo Astronomical Observatory in St Petersburg has published revised calculations of local star positions and velocities to arrive at this prediction.

At first glance it looks like aliens are using the sun for target practice. A string of bullet-shaped streaks of light appear to be shooting straight toward the sun.

These are proverbial snowballs in Hell, plunging 300 miles per second toward a fiery end in the sun's atmosphere.