Astronomers have discovered a binary system of a blue giant and a pulsar that operate as a natural particle accelerator, raising the energy levels of simple photons to some of the highest possible energies. The discovery was made by while watching how the pulsar periodically passes through disk of material ejected by the rapidly spinning blue giant. Each time the pulsar sweeps through this material, its intense magnetic field interacts with the ejected material and boosts photons from regular visible light into the range of super-high gamma rays which blast out in all directions. Some of this radiation interacts with our atmosphere, which is why we can detect it here on Earth.

All three MARSIS booms on Mars Express are now fully deployed, and the spacecraft is ready to begin searching Mars for underground sources of ice and water. The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) consists of two 20-metre (66 foot) and one 7-metre (23 foot) boom. Controllers turned on the radar and performed a brief test, but they're still planning on an extensive commissioning phase until July 4, when the instrument will be ready for full operations.

New images taken by NASA's Deep Impact spacecraft show the actual nucleus of its target, Comet Tempel 1. The nucleus is the heart of the comet, and largely composed of ice and rock. Surrounding that is a halo of gas and dust that largely obscures the view. Tempel 1 isn't a sphere, but an oblong potato-shaped object, 14 km (9 miles) long by 4.8 km (3 miles) wide. By continuing to watch the nucleus as it approaches, Deep Impact will provide scientists with a better idea of the comet's rotation and orientation, so they can fine tune the final collision on July 4.

Biographies of peoples lives can come off as a dated list of achievements and events. With a subject like Story Musgrave, who has more awards and accomplishments than most, such a list almost clamours to be made. Ignoring this call, Ann Lenehan in her book Story - The Way of Water, presents the person behind the awards. The emotions, philosophy and wishes of an over achiever and a very sensitive, warm individual.

When you look into the night sky with your eyes, or through a telescope, you're seeing the Universe in the spectrum of visible light. Unfortunately, this is a fraction of the entire electromagnetic spectrum, ranging from radio waves to gamma radiation. And that's too bad because different wavelengths are better than others for revealing the mysteries of space. Technology can let us "see" what our eyes can't, and instruments here on Earth and in space can detect these different kinds of radiation. The submillimeter wavelength is part of the radio spectrum, and gives us a very good view of objects which are very cold - that's most of the Universe. Paul Ho is with the Harvard-Smithsonian Center for Astrophysics, and an astronomer working in world of the submillimeter. He speaks to me from Cambridge, Massachusetts.

Although the Moon will be full, there will be plenty of excitement as we start the week with Mars and end with a wonderful conjunction of Saturn, Venus and Mercury. But that's not all, for there are two comets and two galaxies to study as well a meteor shower. This will be a great week for all observers, so open your eyes to the skies because...

Here's what's up!

NASA's Cassini spacecraft took this image of Saturn's F-ring, with one of its shepherd moons, Pandora also in view. Pandora is only 84 km (52 miles) across, but it clearly has a powerful effect on the ring, causing ripples, knots and twists in the ring from afar. You can see the entire shape of Pandora in this picture, because reflected light from Saturn illuminates the moon's dark side.

Does life exist elsewhere in the Universe? This question continues to puzzle scientists, but now Professor David Catling at Bristol University thinks that significant oxygen in the atmosphere and oceans of a distant planet are required for complex organisms to evolve. The fact that it took almost 4 billion years here on Earth means that other planets might not have a lot of time to evolve complex life. Since our Sun still has another 4 billion years before it dies, life has time to flourish, but planets around other, more short-lived stars might not be so lucky.

The unpiloted Progress 18 cargo ship docked with the International Space Station on Saturday, delivering a fresh batch of supplies. The spacecraft nearly connected automatically to the Zvezda Service Module, but Commander Sergei Krikalev had to take over because of communications problems between ground control and the Progress.ship. It's loaded up with food, propellant, oxygen, water, spare parts, and experiment hardware. It also brought along the new camera system that will help astronauts inspect the space shuttle for damage when it docks.

Named after Harvard University astronomer Bart Bok, Bok globules may not be the most romantic sounding phrase in astronomy, but they are widely accepted as an important step in the formation of new stars. Now a team of fourteen astronomers - headed by Ryo Kandori of the National Astronomical Observatory of Japan - reports examining ten globules in near-infrared and radio-frequency light along with previously detected data from four others, to determine how many of them are stars in the making...

Which came first, galaxies or the supermassive black holes at their centre? Most cosmologists now think the two are inextricably linked, each depending on the other. And according to researchers, including famed astronomer Sir Martin J Rees, these supermassive black holes got big, fast. By reviewing quasar data in the Sloan Digital Sky Survey (SDSS), the team has calculated that many supermassive black holes had reached 1 billion times the mass of our Sun in a very short period of time. Even for the largest, most voracious black holes in the Universe, that's an amazing feat.

The reentry module of the European Space Agency's unmanned Foton-M2 mission has returned to Earth, landing in Kazakhstan, close to the Russian border. The Foton-M2 contained 39 space experiments, including fluid physics, biology, crystal growth, meteoritics, radiation and exobiology. It remained in space for 16 days, and then was de-orbited and landed safely. The spacecraft is being returned to Europe so the various experiments can be returned to the investigators.

The European Space Agency's Mars Express spacecraft has successfully deployed its second MARSIS 20-metre (66 foot) radar boom; without a hitch this time. Learning their lesson from the first boom, which partially locked up during deployment, ESA controllers put Mars Express into a slow spin so that the boom and its hinges would be evenly warmed by the Sun as it extended. The shorter third and final boom will be deployed on June 17. Once the three booms are extended, Mars Express will be able to scan underneath the surface of Mars for deposits of water and ice.

The space shuttle Discovery has returned to launch pad 39B at Florida's Cape Canaveral to continue preparations for its July launch. The shuttle recently had its external fuel tank replaced with one that would minimize ice buildup. NASA is planning to launch Discovery during its July 15 - 31 flight window. During the 12-day mission, seven astronauts will test new hardware and techniques designed to improve the safety of the space shuttles, and they will also dock with the International Space Station and deliver supplies.

Many of the Earth's volcanic rocks might have come from melted asteroids, according to researchers from the UK's Open University. The scientists have discovered that many early asteroids were quite volcanic and would have had large magma oceans. These asteroids would have become layered with lighter rock forming near the surface while denser rocks were deeper inside. The Earth probably grew from the accumulation of these melted asteroids.

When the recent discovery of a planet orbiting Gliese 876 was announced by astronomers, much of the interest focused on how "Earthlike" it is. So, just how like our home planet is it? Well... not very. For starters, the planet orbits only .021 the distance from the Earth to the Sun, and whips around its star once every 2 days. It has 6-8 times the mass of the Earth, so the gravity would be crushing for any potential life, not to mention the terrible radiation exposure from being so close to its parent star.

Jets of material seem common in the Universe; blasting away from black holes, neutron stars, the hearts of galaxies, and even newborn stars. Unfortunately, the source of these jets are usually obscured by thick dust. Astronomers using the submillimeter array have been able to peer through this dust and see right down the throat of a nearby jet in a young star system called Herbig-Haro 211. It will eventually become a low mass star similar to our Sun, and help explain the stages stars go through in early life.