The Earth's magnetic field concentrates solar radiation into a series of regions called the Van Allen belts. Any spacecraft or astronauts passing through these regions must take precautions or be showered with radiation. But NASA scientists have learned that a "safe zone" between the belts actually moves around depending on the amount of solar activity reaching the Earth. The measurements were made using several meteorological satellites which periodically dipped into the Van Allen belts and through these safe zones.

When President Bush announced his new Vision for Space Exploration in January 2004, he set NASA on a new course to return to the Moon, and maybe even set boots on the surface of Mars in the next few decades. Instead of a quick course change, NASA would work within a modestly increased budget to develop the new Crew Exploration Vehicle, while completing the International Space Station and retiring the Space Shuttle. Science, such as the Hubble Space Telescope, Mars rovers, and climate research wouldn't be affected.

Pluto and its three moons were likely formed together when two large objects collided millions of years ago. Charon has been observed for decades, but the two new smaller moons, discovered last year, also orbit in the same plane as Charon and have a similar orbital resonance. It's even possible that Pluto has a ring system. Astronomers now believe that many Kuiper Belt Objects have multiple moons, and even higher order systems will probably be discovered in the years to come.

This image of the lunar crater Billy was captured by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft. With a diameter of 46 kilometres (29 miles), crater Billy is located on the southern fringes of the Oceanus Procellarum. The floor of Billy has been filled by basaltic lava with a very low albedo, leaving a dark surface. This image was taken on the 14th Jan. 2006, from a distance of about 1260 kilometres.

NASA's Spitzer Space Telescope has uncovered a hot extrasolar planet orbiting a nearby star. Planet HD 189733b orbits its parent star only 63 light-years from Earth, making it the closest extrasolar planet ever detected directly. It moves in an extremely tight orbit - less than 3% of the distance from the Earth to the Sun - completing a tour around its star in just over 2 days. And it's scorching hot, reaching temperatures of 844 Celsius (about 1,551 Fahrenheit) on its surface.

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.