An Ariane 5 rocket blasted off Thursday from Kourou, French Guiana carrying two satellites: Spaceway 2 broadcast satellite for DIRECTV, and the Telcom 2 communications satellite for PT Telekomunikasi Indonesia Tbk. The combined weight of the two satellites was more than 8,000 kg (17,500 pounds), making this the heaviest double payload ever launched.

NASA/Stanford's Gravity Probe B spacecraft recently wrapped up a year of gathering data about the Earth's gravity field. If Einstein was correct, the Earth's rotation should twist up our planet's gravity field like a vortex. Scientists at NASA and Stanford are now analyzing the mountains of data sent back by the spacecraft to detect any shift in its orientation, which would indicate this vortex of gravity.

Astrophysicists at Lawrence Livermore National Laboratory have developed a computer simulation that fails to support one of two major theories of star formation: the competitive accretion model. In this model, clumps form in hydrogen clouds which then collapse to form stars which compete with surrounding stars for material. The simulation showed that turbulence around the newborn star would prevent additional material from falling into the star.

NASA's Spirit Mars rover recently observed the Martian moon Phobos pass through Mars' shadow. When this event happens here on Earth, it's called a lunar eclipse, as the Moon darkens and then brightens again as it passes through our shadow. This "Phobal eclipse" lasted about 26 minutes, but Spirit was only able to capture images from the first 15 minutes.

This is the best photograph ever taken of Saturn's F ring shepherd moon Pandora, taken by the spacecraft on September 5, 2005. This tiny moon is only 84 kilometers (52 miles) across, and covered in grooves and small ridges. This indicates that it's probably coated in dust-sized material, which then fractures in places. Cassini was 52,000 kilometers (32,000 miles) from Pandora when it took this picture.

ESA's Integral gamma-ray observatory has discovered a new class of X-ray fast transient binary stars, which had gone undiscovered in previous observations. This new class of double stars systems always has a bright supergiant star with some kind of compact companion - like a black hole, neutron star or pulsar. It gives off energetic busts of X-rays which flare up quickly and then fade away. It's possible that the compact companion tangles up the supergiant's powerful solar wind with its gravity, and then feeds on it in bits and pieces.

This unique photograph, taken by NASA's Chandra X-Ray Observatory, contains not one, but two supernova remnants. The pair are known as DEM L316, and they're located in the Large Magellanic Cloud galaxy. The gas shell at the upper-left contains considerably much more iron, so it's probably the product of a Type 1a, triggered by the infall of matter from a companion star onto a white dwarf. The lower-right shell is a Type II supernova, the remains of a massive star that exploded a few million years into its short life.

In this face-on view of Saturn's rings, the darker Cassini Division is clearly visible. On the left is Saturn's massive B ring, which is has its edge maintained by Mimas, one of its moons. This photograph was taken on May 18, 2005, when Cassini was approximately 1.6 million km (1 million miles) from Saturn.

NASA has announced that its Ames Research Center will manage the agency's new Robotic Lunar Exploration Program. Before humans set foot on the Moon again, a fleet of robots will map the lunar surface in tremendous detail. NASA Ames has already sent robots to the Moon; most recently the Lunar Prospector, which was launched on January 6, 1998. The spacecraft orbited the Moon, and found evidence of water ice at its poles.

Star-forming region NGC 1333 is located 1,000 light-years away in the constellation Perseus, and is normally enshrouded by thick dust. NASA's Spitzer Space Telescope used its infrared capabilities to pierce this dust layer to reveal the young stars hidden inside. Astronomers are hoping to use Spitzer to spot any nascent planetary structures around these young stars. Now that they're getting going, the young stars are firing out jets of radiation that are steadily clearing the surrounding region of additional dust.

Greetings, fellow SkyWatchers! With plenty of Moon and Mars to go around this week, let's see what else we can find as we begin by honoring the Southern Hemisphere and 47 Tucanae. We'll explore in Cassiopeia, watch for the Leonid meteor shower, capture double stars and look at both northern - and southern - spiral galaxies. So keep your eye on the sky...

Because here's what's up!

One of the most intriguing ideas that pursued by philosophers, artists, and scientists throughout the ages is the one of other dimensions. Is it possible that there is another reality hiding right before our eyes? In his latest book Hiding in the Mirror: The Mysterious Allure of Extra Dimensions, from Plato to String Theory and Beyond, Dr. Lawrence Krauss explores the existence of extra dimensions in culture and science.

One of the most iconic images taken by the Hubble Space Telescope is of the Eagle Nebula, aka the "Pillars of Creation". NASA's Spitzer Space Telescope has taken a similar photograph of a region in the Cassiopeia constellation called W5. This region is dominated by a single massive star blowing powerful solar winds. The surrounding dust and material has been cleared, and compacted into the pillars - these contain clusters of newborn stars.

Venus is our nearest planetary neighbour. Compared to the Earth, it's nearly identical in size and distance from the Sun. But that's where the similarities end. While we enjoy our comfortable temperature, pressure and atmosphere, Venus' environment is downright hostile to life. The European Space Agency's Venus Express blasted off for our "evil twin" planet today, and will hope to help answer the question: what went wrong? My guest today is Larry Esposito from the Laboratory for Atmospheric and Space Physics at the University of Colorado. He's a member of the Venus Express science team.

One of the many hassles of returning humans to the Moon will be the lunar dust. This tiny, gritty, static-loving dust will get into everything, jamming seals, wearing down equipment, and generally causing astronauts endless headaches. Larry Taylor from the University of Tennessee is proposing that astronauts use a heated "lawn mower" to melt the surface of the Moon around their base camp to fuse the dust into larger pieces which won't be so destructive. Lunar dust will melt down with surprisingly little energy because it contains microscopic beads of pure iron which can fuse the grains together.

In this amazing image taken by NASA's Cassini spacecraft, you can see three of Saturn's moons. Dione is on the left, and it's possible to see a large impact crater on the bottom right. Tethys is in the middle, and tiny Pandora is visible against the rings. Cassini took this image on September 22, 2005 when it was 1.2 million kilometers (800,000 miles) from Saturn.

An international team of researchers have developed a new computer model that simulated Jupiter's incredible weather systems. Jupiter's weather is much different from the Earth's, as the strong winds continuously circle the planet, changing very little over time. The massive East-West winds in Jupiter's equatorial region can reach speeds of 550 kph (340 mph). The simulation predicts that the planet's hot interior powers these winds, and explains why they can stay so stable for centuries.

This Hubble Space Telescope photograph shows NGC 346, a star forming region in the Small Magellanic Cloud (SMC). The radiation pouring out of the young hot star at the heart of the nebula is pushing out the surrounding gas and dust creating the beautiful shapes in the image. The small dark globules of material point back at the star like windsocks. NGC 346 can be resolved into at least three different sub-clusters of material each of which contains several more hot, blue, high-mass stars.