Europe's innovative Goce satellite has switched on the super-sensitive instrument that will make ultra-fine measurements of Earth's gravity.

The sophisticated gradiometer will feel the subtle variations in Earth's tug as it sweeps around the globe.

Female finches from Northern Australia are controlling the sex of their offspring, according to the head colour of their male counterpart.

The finding, published today in the journal Science, is one of the first to clearly show that birds are capable of biasing the sex of their offspring to overcome genetic weaknesses.

Lead author Dr Sarah Pryke, of the Department of Brain Behaviour and Evolution at Macquarie University in Sydney, admits the mechanism by which the birds do this is not yet known.

Astronomers have captured the sharpest image of a young binary star in the heart of Orion, in which one can clearly distinguish the two stars of the system.

The new image of the double star, Theta 1 Orionis C, was taken with the European Southern Observatory's Very Large Telescope Interferometer (VLTI), astronomers from the Max-Planck-Institute for Radio Astronomy in Bonn, Germany, reported in the journal Astronomy and Astrophysics on Thursday.

Theta 1 Orionis C represents the brightest and most massive star in Orion Trapezium Cluster, the nearest high-mass stars-forming region to Earth, and scientists describe it as a unique laboratory for studying the formation process of massive stars in detail.

Gary Anderson was not around to see a backhoe tear up the buffalo grass at his ranch near Akron, Colorado. But he was watching a few weeks later when the technicians came to dump instruments and insulation into their 2-metre-deep hole.

What they left behind didn't look like much: an anonymous mound of dirt and, a few paces away, a spindly metal framework supporting a solar panel. All Anderson knew was that he was helping to host some kind of science experiment. It wouldn't be any trouble, he'd been told, and it wouldn't disturb the cattle. After a couple of years the people who installed it would come and take it away again.

He had in fact become part of what is probably the most ambitious seismological project ever conducted. Its name is USArray and its aim is to run what amounts to an ultrasound scan over the 48 contiguous states of the US. Through the seismic shudders and murmurs that rack Earth's innards, it will build up an unprecedented 3D picture of what lies beneath North America.

Lasers might be pushing 50, but they are still the youthful pin-ups of fundamental physics. Since the first one was unveiled in 1960, the more apocalyptic predictions of how they might be used - as death rays, for example - have proved to be overblown. Their peaceful application, on the other hand, can be seen everywhere from cutting and welding to combating cancer and cataracts, to powering telecoms and consumer electronics, and has mushroomed into an industry worth $6 billion in 2007. Advances in the laser lab translate into gadgets in our homes at astonishing speed: think of the progression from CD to DVD and now Blu-ray technology in just a few decades.

So here's a heads-up for you: we could be about to witness the next stage in the laser's evolution, a sea change in how laser light is produced. A new wave of devices looks likely to exploit particle-like packets of energy to produce their light - packets that are neither light, nor matter, but both. It's early days, but advances in taming these exotic beasts are proceeding apace. "I keep expecting progress to end," says physicist Jeremy Baumberg at the University of Cambridge, one of the pioneers. "But it just keeps going." The pay-offs could be immense: not just lasers that use less juice than ever before and new low-power lighting technology but maybe even a way to make the semi-mythical, superpowerful quantum computer.

Beltway for electrical energy solves long-standing problem

MIT engineers have created a kind of beltway that allows for the rapid transit of electrical energy through a well-known battery material, an advance that could usher in smaller, lighter batteries -- for cell phones and other devices -- that could recharge in seconds rather than hours.

The work could also allow for the quick recharging of batteries in electric cars, although that particular application would be limited by the amount of power available to a homeowner through the electric grid.

The work, led by Gerbrand Ceder, the Richard P. Simmons Professor of Materials Science and Engineering, is reported in the March 12 issue of Nature. Because the material involved is not new -- the researchers have simply changed the way they make it -- Ceder believes the work could make it into the marketplace within two to three years.

Swift's primary job is to quickly alert astronomers about new gamma-ray bursts - powerful explosions from distant dying stars. "But Swift's rapid response and flexibility allow us to perform other science while the spacecraft is waiting for gamma-ray bursts to occur," said presenter Geronimo Villanueva, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

From its orbital perch, Swift can view targets using ultraviolet wavelengths, visible light, and X rays -- and it's the only observatory that sees them at the same time. Between bursts, astronomers task Swift to survey the entire sky at X-ray wavelengths, monitor exploding stars, image galaxies, and study comets.

Comets are clumps of frozen gases mixed with dust sometimes called "dirty snowballs." These icy bodies cast off gas and dust whenever they venture near the sun. Most recently, Swift observed Comet Lulin as part of a study led by Jenny Carter at the University of Leicester, U.K. Lulin was faintly visible to the naked eye when it passed 38 million miles from Earth --- or about 160 times farther than the moon - in late February.

Enormous cosmic voids and giant concentrations of matter have been observed in a new galaxy survey, one of the biggest completed so far. One of the voids is so large that it is difficult to explain where it came from.

Called the Six Degree Field Galaxy Survey (6dFGS), the project scanned 41% of the sky, measuring positions and distances for 110,000 galaxies within 2 billion light years of Earth.

No previous survey has covered as much of the sky at such a distance. The Sloan Digital Sky Survey (SDSS), which is based in the northern hemisphere, has probed about twice as far but covers only 23% of the sky.

A team led by Heath Jones of the Anglo-Australian Observatory in Epping, Australia, announced the completion of the survey on Friday. The project used the 1.2-metre UK Schmidt Telescope in Australia and as a result looked only at parts of the sky visible from the southern hemisphere.

Asteroid impact is a very real threat to the earth. While the statistics on the probability of such occurrences vary in certainty, it is generally accepted that objects 5-10m in diameter hit the earth once every year while the odds of a devastating asteroid strike is approximately one in ten chance of hitting per century. Clearly, with the potentially monumental costs of such a devastating strike occurring, it is in our best interest to know as much as we can about potential strikes. Any ability to see such a catastrophe in advance has the potential to be of civilization saving significance, which brings us to the unprecedented observations made of 2008 TC3, an asteroid that fell to Earth late last year.

Back in early October the observers at the Catalina Sky Survey near Tuscon, Arizona discovered a world first. It saw an object in outer space that, after a brief calculation of its orbit, had a 100% chance of hitting the earth. The sense of urgency was increased when they discovered it was going to strike the earth within 20 hours. Luckily the object, cheerfully named 2008 TC3, turned out to be only four meters across, so the worst case scenario was that it would rain down a few small rocks over a small area. While you wouldn't want one to accidental hit you as it was falling, it was of no significant risk to human life or the Earth. It was however our first chance to study an object in space that was also going to be observable after it had entered the Earth. It was a chance to test the accuracy of our space observations.

Seven pyramids have been identified on the African island of Mauritius. Remarkably, in construction, they are identical to the ones found on the island of Tenerife, an island on the opposite side of the continent. It underlines the likelihood that one civilisation sailed to various islands off the coast of Africa and constructed these structures.

The island of Mauritius is part of the Mascarene Islands and is in the Indian Ocean, about 900 kilometres (560 miles) east of Madagascar. The island is 61 km long and 47 km wide, and sits just north of the Tropic of Capricorn. In origin, it is a volcanic island. The historical record shows that the island was known to Arab and Austronesian sailors as early as the 10th century; Portuguese sailors first visited in 1507. Mauritius was first plotted on a map in 1502, made by the Italian Alberto Cantino. The Arabs called the island Dina Harobi, while the planisphere identifies all three Mascarene islands (Reunion, Mauritius and Rodrigues) and calls them Dina Margabin, Dina Harobi and Dina Morare.

It is suspected that prior to the Arabs, Mauritius was known to certain people living on the African shores, as well as the famous Sea Peoples, a confederacy of seafaring raiders, which included the proto-Phoenicians. The Greek account of Periplus [The Periplus of the Erythraean Sea] relates the story of Hanno (Hannan), the Carthaginian navigator, who lived in the 5th century BC, and who traversed the Straits of Gibraltar at the command of ships that would explore the African coastline along the Atlantic Ocean. Herodotus describes a Phoenician expedition leaving the Red Sea and traversing the "sea of the south", and, following the orders of the Egyptian Pharaoh Necho II (610-595 BC), entered back into the Mediterranean Sea through the Straits of Gibraltar, which means they circumnavigated Africa.