The closest stars to our Solar System probably haven't been discovered because it's likely they're of a cool, dim class of failed stars called brown dwarfs. But a new mission from NASA called the Wide-field Infrared Survey Explorer (WISE) has recently been approved for development, and it should be able to locate them. Scheduled for launch in 2008, and costing $208 million, WISE will scan the entire sky in infrared, looking for brown dwarfs, planet-forming disks around nearby stars, and colliding galaxies. Eventually it will build up a database of more than one million images, containing hundreds of millions of objects.

Astronomers using the Gemini observatories have got themselves a bit of a mystery. They've found a binary system at EF Eridanus, located 300 light-years away from Earth, where one of the objects defies classification. It's about the size of Jupiter but it's way too massive to be a planet. It's the temperature of a brown dwarf, but its light doesn't match a brown dwarf's characteristics. The researchers believe that the object was once a regular star, but then it had most of its material stripped away by the gravity of the larger star over the course of 5 billions years. Eventually it just couldn't give any more.

A problem with the wheels on NASA's Spirit rover has stopped it dead in its tracks on the surface of Mars. For some reason, the rover's right-front and left-rear wheels stopped operating as commanded on Oct. 1. NASA engineers have performed a series of diagnostic tests to understand which systems could be affected, and they're still analyzing the results. One fix would be to permanently disable the brakes on those wheels, but it could put the rover at an increased risk. Spirit has now traveled 3.6 km (2.2 miles) across the surface of Mars; much further than it was designed for, so it's no surprise it's starting to have some mechanical problems.

On October 9, 1604, a new star appeared in the sky as bright as any of the planets. Johannes Kepler, who discovered the laws of planetary motion, was one of the astronomers at the time who tried to study this supernova, before telescopes were even invented. Now NASA has turned its Great Observatories (Hubble, Chandra, and Spitzer) on the supernova remnant, and produced an image that shows it in many different wavelengths of light. The combined image shows a bubble-shaped shroud of gas and dust 14 light-years wide expanding at 6 million kph (4 million mph).

Arianespace has announced that they will be launching a cluster of 50 nanosatellites in 2007 to commemorate the 50th anniversary of the first satellite launch of Sputnik in 1957. Each tiny satellite will weigh only 1 kg (2.2 lbs), and contain a scientific package developed by a single country - all 50 will be launched at the same time, on one rocket. The nanosats will last in orbit for about 2 years.

NASA has had two momentous changes in the last few years. One is the loss of the Columbia shuttle. Two is the replacement of administrator Daniel Goldin by Sean O'Keefe. In their book New Moon Rising, Frank Sietzen and Keith Cowing claim that the consequence of these changes is that NASA finally has things right and will accomplish their new vision; to send humans to live in space. This is a very bold claim and though there is not much factual content to support this, the book does provide good detail on the process by which NASA obtained this vision.

Astronaut Gordon Cooper, who piloted missions in both the Mercury and Gemini programs, died on Monday at his home in Ventura, California; he was 77. Cooper was the youngest of the original 7 Mercury astronauts, and his mission on May 15, 1963 - the final one in the Mercury program - lasted more than 34 hours and 22 orbits. Cooper and Pete Conrad flew the third flight of the Gemini program in 1965, and stayed in space for 191 hours, establishing a new space endurance record.

NASA is considering a new space-based telescope that would be the equivalent of a 40-metre (120 ft) observatory. The proposed Space Infrared Interferometric Telescope (SPIRIT) mission would consist of two infrared telescopes at opposite sides of a rail that could be positioned perfectly to combine their images into a single, giant telescope. SPIRIT is being considered as part of NASA's Origins program, which is looking to answer fundamental questions about the beginning of the universe. If selected, it would launch in 2014.

A NASA-funded study has predicted 15 of California's 16 largest earthquakes this decade, demonstrating that scientists are finally getting a handle on the warning signs that lead to big quakes. The team looked at historical earthquake data back to 1932, and then used this to build a model that predicts earthquake hotspots in California. One warning sign that a big quake is going to happen is when there's a series of small earthquakes above magnitude 3 which indicate that pressure is building up; another is when the fault appears to stop entirely.

NASA scientists flew a small aircraft equipped with a special infrared camera above Mount Saint Helens last week to see if this perspective would give any insights into what's happening underneath the surface. Shortly after they took this image, the volcano spewed out a large blast of steam. The team had actually been planning this mission for quite a while, so it was a complete coincidence that they arrived when the volcano was about to erupt.

This image was taken by the European Space Agency's Mars Express spacecraft on June 4, and it shows a series of parallel fault lines in the western part of Solis Planum. These fault lines can be traced for several hundred kilometres to the northern Tharsis shield volcanoes.

Living at the centre of the Milky Way would be beautiful, but dangerous, according to research from the Harvard Smithsonian Center for Astrophysics. Every 20 million years or so, a ring of gas and dust 500 light-years away from the middle of the galaxy collapses, beginning a furious period of star formation, which then sets off a series of supernovae. A planet in the area would be completely sterilized of life as star after star explodes. The next starburst period in the Milky Way is likely to happen in about 10 million years, but don't worry, we're far enough away that nothing would happen to the Earth.

A common science experiment for young kids is to build a pinhole camera. Researchers from the University of Colorado at Boulder think NASA should build a gigantic one in space and use it to find planets orbiting other stars. The "New Worlds Imager" would be a football field-sized opaque light shade with a small opening right at the centre to let light through. A detector spacecraft would sit thousands of kilometres back and collect the light that comes through the opening. The shade would block the light from the star and let astronomers detect planets orbiting it. The proposal was one of 12 advanced concepts recently selected for further study by NASA.

Supernovae are easy to see - after they've gone off. But it's impossible to find the stars beforehand, so you can study their final moments. Astronomers think they've found a warning sign that a star is about to explode: X-ray flashes. NASA's High-Energy Transient Explorer (HETE-2) has spotted three different powerful blasts of x-ray radiation over the last few weeks, and if astronomers' models hold true, these are precursors to much more powerful gamma-ray bursts, which have been linked with supernovae. Many telescopes around the world will be studying the regions that these x-ray flashes happened, hoping to catch a supernova in the act of exploding.

Traveling in space could be hard on your immune system, according to a new study funded by NASA. Researchers tested 25 astronauts before and after various space shuttle missions of varying lengths, and found that white blood cells increased after the astronauts returned from space. The increased number of white blood cells meant that the astronauts bodies were working overtime to fight off various microbes and diseases. And it appears that these effects probably increase as missions get longer and more difficult.

This photo, taken by NASA's Cassini spacecraft, shows the tiny moon Prometheus, which serves as a shepherd to the inside edge of Saturn's knotted F ring. It's only 102 km (63 miles) long, so Cassini had to take several images of it, which were then stitched together on computer to enhance resolution and reduce noise. It was first discovered during the Voyager mission, and scientists saw a hint of the ridges, valleys and craters that marred its irregular surface. Cassini is expected to make a much closer flyby of the tiny moon later in its mission.

Here's a 1024x768 desktop wallpaper from a deep field image taken by the Canada-France-Hawaii Telescope to celebrate its 25th anniversary. This part is actually just a fraction of the full image that contains more than half a million galaxies in just a one-degree square field of the sky. Once one of the larger telescopes in the world, the 3.6-metre instrument has been updated regularly with state of the art technology including adaptive optics and a 340 mega pixel digital camera.

NASA's Institute for Advanced Concepts has selected 12 proposals for further study as part of its goal of finding revolutionary ideas that could help the agency's plans for human space exploration. Proposals selected as part of Phase 1 will receive $75,000 for a six-month study. Those selected for Phase 2 will have two years and $400,000 to further develop their concept. Some of the Phase 1 winners include an infrared observatory on the Moon, lunar space elevators, electrostatic radiation shields and a plasma propulsion system.

As predicted, Asteroid Toutatis made its closest approach to the Earth today, passing a mere 1.5 million km (930,000 miles) away from our planet - 4 times the distance from the Earth to the Moon. The 4.6 km (2.9 mile) long asteroid hasn't made an approach this close since 1353. Since it was first discovered in 1989, Toutatis has been closely studied by astronomers because it has an orbit that brings it close to the Earth every 4 years. Unfortunately, it's still too dim to see with the unaided eye, but skilled amateur astronomers with telescopes watching the southern skies have spotted it. Toutatis won't get this close again until 2562.