UK astronomers have used the Jodrell Bank Observatory to discover an entirely new class of objects. These new kinds of stars are similar to pulsars, as they produce brief radio flashes which only last for a few milliseconds. Unlike pulsars, however, they stay silent for much longer periods of time, ranging from 4 minutes to 3 hours. Astronomers think these objects build up energy over hundreds of rotations, and then release it in a single burst - and then build back up again.

This false colour image of Saturn's moon Enceladus shows incredible features across its surface, invisible in natural colour. The bluish southern regions are deposits of large grains of poure ice, which show that the moon's southern hemisphere is relatively young compared to the meteor pounded northern hemisphere. Cassini took this photo on January 17, 2006 when it was 153,000 kilometers (95,000 miles) from Enceladus.

Australian astronomers have used the powerful Gemini observatory to measure the amount of dark matter in the heart of galaxy NGC 3379. They made their estimate by observing 22 globular clusters near the galaxy's central halo, and then measured their distance from the galactic centre. They were then able to calculate how much dark matter in the galaxy's dark halo was nearby to keep them in this orbit.

When stars near the end of their lives, they expel their outer layers into space. This gas expands and cools, and some of it condenses into grains of dust; eventually this dust comes together to form stars and planets. NASA scientists have built a stardust factory at the Goddard Space Flight Center to model what kinds of conditions are required to generate this dust. It turns out that stars can make this dust at much higher temperatures than previously believed.

In ancient times, skywatchers knew of 5 planets: Mercury, Venus, Mars, Jupiter and Saturn. The fact that Earth was another planet didn't occur to anyone for a few more years. Uranus was discovered in 1781, Neptune in 1846, and tiny Pluto was finally located in 1930. That brought the total number of planets to 9. We were all raised to believe that there are 9 planets. That's it, case closed. Right? Wrong... maybe.

The first astronauts wanted to be more than passengers in their spaceships. However, undertaking an active role meant that systems, interfaces and controls need be suited for human use even though the environment was completely unknown. Mary Jane Chambers and Dr. Randall Chambers in their book Getting Off the Planet provide a first hand account of some of the challenges that were mastered in resolving this issue and in meshing human to machine. As they note, with judicious testing and training, there was much greater confidence in the success of all the space missions.

Greetings, fellow SkyWatchers! With the Moon exiting the early evening scene it's back to deep sky as we have a look at open clusters, supernovae, and protostars. The weekend serves up a galactic dish and a meteor shower to wash it down. Time to turn an eye to the sky, because...

Here's what's up!

Since it's often hidden by the glare of the Sun, you don't get many chances to see Mercury. Well, now's your chance. From now until March 1, Mercury will be clearly visible in the west as twilight turns to night. Friday, February 24th will be the best night to look for Mercury, and a thin crescent moon will be close to the planet on March 1st. NASA's Messenger spacecraft is on its way to Mercury, and is expected to arrive in 2008. Until then, make sure you get outside, look west, and enjoy a view of this tiny planet.

The iron meteorites whizzing around the Solar System are probably remnants of objects that helped form the Earth and the other rocky planets. When they fall down to Earth, scientists get an opportunity to study some of the primordial building blocks of our planet. Although many of the Solar System's asteroids are found in the asteroid belt, they probably emerged out of the same disk of planetary debris that formed the Earth, and then drifted out to their current location.

Scientists at the University of Chicago have received their first samples of cometary dust from NASA's Stardust mission, which returned back to Earth in mid-January. The samples consist of several thin slices of a single dust grain, as well as a larger piece which can be sliced up even finer. Mission scientists believe that the spacecraft collected a total of 2,300 particles larger than 15 micrometres across (1/3rd the width of a human hair).

Astronomers now know that the haze of the Milky Way is actually the combined light of millions of stars. The Milky Way has a similar haze in the X-ray spectrum, and that also seems to be coming from a multitude of point sources. Astronomers pooled together 10 years of observations from the Rossi XTE orbital observatory, and they were able to determine that the emissions are coming from a million white dwarf stars, and hundreds of millions of stars with active coronas.

In orbit for more than a year and a half now, NASA's Cassini spacecraft is only just now getting around to imaging Saturn's northern hemisphere. It's winter in northern Saturn right now, and scientists want to know if the two hemispheres experience different weather patterns depending on the seasons. Cassini took this image on January 6, 2006 when it was 2.9 million kilometers (1.8 million miles) from Saturn.

Astronomers have been puzzling over a mystery for a few years now, and they think they might have an answer. Everywhere you look, there's a diffuse glow of background X-ray radiation - but where's it coming from? Astronomers pointed the Chandra X-Ray Observatory at a patch of sky for a total of 23 days over a 2-year period, and resolved 600 separate point sources. This isn't a background glow at all, but the X-ray radiation from hundreds of millions of supermassive black holes, like the one at the heart of the Milky Way.

There are many icons that represent the universe: brilliant stars, the rings of Saturn or something as familiar as Earth's own Moon. But for many, one of the images that best symbolizes the awe and mystery of deep space is the haunting beauty of the Sombrero Galaxy, also known as M-104.

Mars' moon Phobos casts its shadow across the surface of the Red Planet in this photograph captured by ESA's Mars Express. Phobos is only 27 kilometres by 22 kilometres in size (17 x 14 miles), and it orbits Mars once every 7.5 hours. To an observer on the ground, this eclipse would look similar to one on Earth; however, Phobos would only cover about 20% of the Sun's surface. And it would be over quickly - the shadow moves at 7200 km/h (4400 mph).

Cassini captured two of Saturn's moons in this image: Titan and Tethys. Titan is in the upper left, and is shrouded by a thick atmosphere that protects it from most impacts. Tethys, on the other hand, has no atmosphere, and has suffered numerious impacts, including the enormous impact that dug out the crater Odysseus. This image was taken on January 6, 2006, when Cassini was 2.7 million km (1.7 million miles) from Tethys, and almost double that distance from Titan.

ESA's Mars Express spacecraft has spotted evidence of auroras over the night time side of Mars. These auroras make v-shaped structures of accelerated electrons and ions, similar to what we see here on Earth. Mars doesn't have a planetary magnetic field, so the discovery of auroras came as a surprise; however, it does have magnetic regions - the remnants of an old planetary magnetic field. Since Mars is always lit from our vantage point here on Earth, it required a spacecraft to find the auroras, which are only detectable at night on Mars.

After 100 days of travel, ESA's Venus Express tested its main engine for the first time. The burn only lasted 3 seconds, and changed the spacecraft's velocity about 3 metres/second (10 feet/s). The engine test worked perfectly, and Venus Express was able to reorient itself after the burn, and correctly point its high-gain antenna back at Earth. The engine will be used again on April 11, when it will fire for 51 minutes, putting it into orbit around Venus.

According to new research published by NASA scientists, Greenland's glaciers are losing ice at an accelerating rate. In the period from 1996 to 2005, the island's glaciers doubled the amount of ice they're shedding annually into the world's oceans. This acceleration is due to a global rise in temperature. Once Greenland's glaciers are all gone, scientists estimate world sea levels will have risen approximately 7 metres (23 feet).

Our five senses are all we have to allow our brains to interact with the world outside our bodies. Space exploration relies almost entirely on one, the sense of sight. Space probes send us images of planets, moons and other objects which we then have to decipher as best we can. Richard Greenberg in his book Europa, The Ocean Moon uses recent images of Europa, together with our understanding of celestial mechanics and plate tectonics, to unravel this little moon's mysteries. For Europa's biggest mystery is whether it harbours life who may be looking right back at us from their own little world.