A global team of radio astronomers think they might have found the youngest black hole or neutron star approximately 30 million light-years from Earth. A supernova in exactly the same location was found to have exploded some time around 1983, and subsequent observations have found a brightly-emitting object at the very centre of the supernova remnant. They still can't tell if it's actually a black hole, or just a neutron star or pulsar, so further measurements will be required.

NASA's Cassini spacecraft is set to make its first and only flyby of Saturn's moon Phoebe on Friday at 2056 UTC (4:56 pm EDT). The tiny moon is only 220 km (137 miles) across, and Cassini will get within 2,000 kilometres (1,240 miles). This picture was taken on June 10 - one day before its closest encounter - when Cassini was still 658,000 kilometres (409,000 miles) away, so the resolution of the image is going to get much much better. Cassini will reach Saturn at the end of the month.

When Galileo went past Jupiter's moon Io, it found parts of it reached temperatures as high as 1,610 degrees Celsius (2,910 Fahrenheit). The moon is so hot because it's continually being squeezed by Jupiter's immense gravity - the friction from the tidal interaction keeps it warm. Observations from Galileo and Earth-based telescopes have seen that the volcanoes are so hot they're vapourizing sodium, potassium, silicon and iron into the moon's atmosphere.

Here's a 1024x768 wallpaper of a region of Mars called Mangala Valles taken by the ESA's Mars Express spacecraft. The region is located on the southwest Tharsis Bulge, and it looks like it was significantly shaped by liquid water some time in the distant past. Similar regions are here on Earth, where volcanic activity causes underground water and ice to suddenly burst forth in a catastrophic flood. In addition to the large outflow channels, there are smaller ones off to the side that could have been caused by rainfall.

The 8-metre Gemini South telescope has been coated with pure silver to give it more resolution when viewing objects in the infrared spectrum. A total of only 50 grams (2 ounces) of the precious metal were required to coat the entire glass mirror, which had previously been covered with aluminum. It didn't require much silver, but it was extremely difficult to apply. Workers used devices called magnetrons which surround a pure metal bar with a cloud of gas which knocks atoms of silver and allows them to deposit on the mirror at a perfect thickness of 0.1 microns (1/200th the thickness of a human hair).

Astronomers have used the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite to detect molecular nitrogen in interstellar space. Nitrogen is common in the Earth's atmosphere, and believed to be the fifth most abundant chemical in the Universe, but astronomers hadn't been able to find it in interstellar molecular clouds, where it's believed to be very common. This discovery should help astronomers better understand the formation of stars and planets out of clouds of dust and gas.

The European Space Agency has decided on how it will contribute to the construction of the next generation James Webb Space Telescope (JWST), due for launch in 2011. The Europeans will work with the USA on the Mid-Infrared Instrument (MIRI), which is one of four instruments on board JWST. MIRI will be used to study old and distant stellar populations, dust obscured regions of star formation, and comets and Kuiper Belt objects. JWST will be three times larger than Hubble and be able to resolve objects 10 to 100,000 times better depending on the wavelength and type of observation.

Since its existence was first theorized in the 1960s, scientists have been searching for the mysterious Higgs boson. This subatomic particle is believed to be responsible for mass, and would help explain why objects feel inertia and have momentum. Unfortunately, physicists were unable to find the particle in the 1990s using the world's largest atom smashers. A new estimate for the particle's mass from Berkeley Lab explains why it might have eluded discovery. Fortunately, CERN's new Large Hadron Collider, due to start up in 2007 should have the ability to find the Higgs particle at a heavier mass.

Now only three weeks from entering orbit around Saturn, it's time for Cassini to begin making some close up observations. Its first target is the tiny moon Phoebe, which is only 220 kilometres (137 miles) across. The images are already better than anything taken by Voyager 2, and show a varied surface, with mountains and craters. Cassini will get its best view on June 11 when it zooms past the moon at a distance of only 2,000 kilometres (1,240 miles). It should have enough resolution at the point to see objects the size of office buildings.

Scheduled for launch in 2006, the New Horizons mission will finally get a close up view of Pluto, the only planet never visited by spacecraft. On board the robotic spacecraft will be the Solar Wind Around Pluto (SWAP) instrument, which will measure the interactions between Pluto and the high-speed stream of particles flowing out from the Sun called the solar wind. Since it'll be so far from the Sun, SWAP will be largest aperture device ever built to measure the solar wind. It'll have lots of time to measure; the trip to Pluto will take 9 years.

A new simulation of galaxy formation developed at the University of Chicago does a much better job of predicting what astronomers actually see when they look through their telescopes. The simulation is based on an extension of the Big Bang theory called the "cold dark matter theory" that describes how early galaxies collided and merged to create the different objects we see today. Dwarf galaxies which orbit larger galaxies seem to be a key to this process.

Satellites are giving scientists a bird's eye view of deforestation in the Brazilian rainforest, and the impact this is happening on the local environment. The researchers studied many years of data gathered by NASA's Tropical Rainfall Measuring Mission (TRMM), and found that the land heated up more quickly in the deforested areas. The increased temperatures let to more evaporation and greater rainfall during normally drier seasons. This challenges previous theories that said deforestation would lead to more arid conditions.

Opportunity has been gingerly testing the edge of Endurance Crater to make sure it's stable enough for the rover to roll in without slipping down the slope. If that works out, the rover will enter the crater today and begin 2-3 weeks of scientific study, analyzing exposed layers of rock to get a better picture of water that covered the area millions of years ago. Scientists are expecting the crater will return a tremendous amount of scientific data because it's much deeper than Eagle Crater, which Opportunity first landed in when it arrived on Mars.

When life first arose on the Earth, 4.6 billion years ago, the Sun was putting out 20-25% less energy - our planet should have been an iceball... why wasn't it? Evidence from ancient rocks shows that there was a large amount of carbon dioxide and methane in the Earth's atmosphere, which would have helped warm the planet. But these levels were tied to early weather and plate tectonics which carried the greenhouse gasses into and out of the atmosphere, leading to several early ice ages. New research from Stanford has turned up rocks that give an accurate picture of how these gas levels rose and fell over the first few billion years.

NASA's Opportunity rover is continuing to circle the rocky rim of Endurance Crater, searching for the right place to try and go in. At its deepest point, the crater descends 20 metres (66 feet), so operators are looking for a sheet of stable rock that will stop the rover from slipping in the Martian sand. So far, it looks like the slope is 18 to 20 degrees, which is within the rover's ability to climb back out - just barely. In Eagle crater, where Opportunity landed, the rover was unable to get out from a 17-degree slope because of fine dust at the top of the crater's rim.

Astronomers studying the famous Whirlpool Galaxy (M51) have discovered important clues which support theories of how spiral arms can last so long in a galaxy without winding themselves too tightly. M51 is seen face on, so astronomers can see the galaxy's entire structure. A group from the National Radio Astronomy Observatory analyzed clouds containing carbon monoxide molecules and found that they regularly pass through a region of higher density and temperature. This stirs up the gas and prevents it from collapsing into regions of active star formation, and allows the spiral formation of the galaxy to last longer.

The "X" on this image of Saturn indicates the spot where Cassini will cross the ring plane when it goes into orbit around the Ringed Planet. This image of Saturn's rings was taken on May 11, 2003, when Cassini was 26.3 million km (16.3 million miles) from the planet. There are also two moons visible in this image: Janus and Pandora. Cassini will arrive on June 30, 2004.

We're just hours away from the first transit of Venus across the surface of the Sun since 1882. Sky watchers across Europe, Africa and Asia will be perfectly situated to watch the transit as it happens during the day. Venus' first contact begins on June 8 at 0513 UTC (1:13 am EDT) and completes approximately six hours later. You can watch the transit if you've got the right equipment (a properly set up telescope with a solar filter), but it can be extremely dangerous to watch with the unprotected eye. The Americas won't have a good view this time around, but don't worry, there's another coming in 8 years.