Three new moons discovered around Saturn by the Cassini spacecraft have been given provisional names. The discoveries were made last year, not long after Cassini had arrived in orbit around the ringed planet. Two moons detected in August have been given the names Methone and Pallene, while another found in October has been provisionally named Polydeuces. Three more candidate objects are still awaiting confirmation as moons.
Space yacht rides to stars on rays of sunlight
(Feb 27, 2005)
A spacecraft that flies on sunbeams is about to begin its travels across the solar system. A group of American and Russian scientists are preparing to launch a probe with giant, wafer-thin plastic sails that can catch sunlight just as a yacht's sails fill with wind. Cosmos-1 has been designed to tack across space without using rockets and could form the forerunner of a network of solar observatories that would hover over the sun to provide early warnings of disruptive magnetic storms, or deliver instruments to remote space stations and planetary exploration teams.
Ice age bacteria brought back to life
(Feb 26, 2005)
A bacterium that sat dormant in a frozen pond in Alaska for 32,000 years has been revived by NASA scientists. Once scientists thawed the ice, the previously undiscovered bacteria started swimming around on the microscope slide. The researchers say it is the first new species of microbe found alive in ancient ice. Now named Carnobacterium pleistocenium, it is thought to have lived in the Pleistocene epoch, a time when woolly mammoths still roamed the Earth. NASA astrobiologist Richard Hoover, who led the team, said the find bolsters the case for finding life elsewhere in the universe, particularly given this week's news of frozen lakes just beneath the surface of equatorial Mars.
Frozen sea on Mars linked to elevated methane
(Feb 25, 2005)
The discovery of a frozen sea on Mars has ignited a new debate on whether life existed on the Red Planet. Most intriguing is the claim that the atmosphere above the frozen ocean in the Elysium Planitia region may have elevated concentrations of methane. If true, it could suggest that primitive micro-organisms might even survive on Mars today, according to Jan-Peter Muller, at University College London, and one of the team that found the frozen sea. The team, which was led by John Murray at the Open University, UK, analysed images taken by Europe's Mars Express spacecraft. "If the ice is still there, then Elysium is the most likely place to find past or present life on Mars," says Murray. He presented the findings at the 1st Mars Express Science Conference in Noordwijk, the Netherlands, on Monday. Immediately after his talk, Vittorio Formisano, chief scientist for Mars Express's Planetary Fourier Spectrometer (PFS) which measures the composition of gases in the planet's atmosphere, commented: "Elysium Planitia is indeed the region where we have seen the maximum of methane coming out of the surface."
Martian pole reveals ice age cycles
(Feb 25, 2005)
Pictures of Mars's north pole have revealed a record of the planet's climate over the past 3 million years. The climate history is written in light and dark bands exposed on the sides of ice cliffs. Scientists now say that they can read these bands in the same way as climatologists on Earth interpret cores drilled from deep-sea sediments. Sarah Milkovich and James Head, geologists from Brown University in Rhode Island, used a series of images from the Mars Orbiter Camera on board NASA's Mars Global Surveyor craft.
Quark soup may cause cosmic flashes
(Feb 25, 2005)
Intense flashes of gamma rays in far-off galaxies might be produced by a bizarre kind of star, consisting of phenomenally dense material in which the particles that make up atomic nuclei have fallen apart. Two astrophysicists have proposed that gamma-ray bursts, whose origins have foxed astronomers for decades, might be the signatures of elusive 'quark stars'. Scientists have speculated that these stars might exist, but have never seen convincing evidence for them. (Image: putative quark star RX J185635-375)
Astronomers have discovered an object that appears to be an invisible galaxy made almost entirely of dark matter. The team, led by Cardiff University, UK, claims it is the first such object to be detected. A dark galaxy is an area in the Universe containing a large amount of mass that rotates like a galaxy, but contains no stars. It was found 50 million light-years away using radio telescopes in England and Puerto Rico.
Our planet's murky deep sea sediments are a buzzing hotbed of life, according to a report in Nature magazine. Scientists suggest between 60 to 70% of all bacteria live deep beneath the surface of the Earth, far from the Sun's life-giving rays. Some of the new bacteria identified are about 16 million years old, surviving 400 metres below the sea bed. This hostile habitat might be where life first evolved more than 3.8 billion years ago, researchers believe.
Huygens detects geological activity on Titan
(Feb 23, 2005)
The Huygens probe that roared through Titan's atmosphere has provided the strongest evidence yet to suggest Saturn's giant moon is geologically active beneath its icy surface. The ratio of carbon isotopes 12C and 13C in Titan's atmosphere, measured by the probe's Gas Chromatograph and Mass Spectrometer (GCMS) instrument, indicates that methane is being replenished on the freezing world. Continuing geological activity beneath the surface is thought to be the most likely source. The Cassini-Huygens mission has already produced remarkable insight into the enigmatic and inhospitable moon, which is unique among the planetary satellites in our solar system in having its own atmosphere.
Fast-spinning star could test gravitational waves
(Feb 22, 2005)
One of the fastest-spinning stars ever seen has been found by the INTEGRAL spacecraft. But researchers say the star's speed could be limited by gravitational wave radiation – theoretical ripples in space-time. The idea could be tested by upgraded detectors within the next few years. The European Space Agency's INTEGRAL spacecraft, launched in 2002 to study high-energy phenomena in space, detected the star on 2 December 2004. Called IGR J00291+5934, the object appears to lie about 9800 light years away and emits a periodic signal every 1.7 milliseconds. That is the telltale signature of a type of neutron star called a "millisecond pulsar" – one that spins at least 100 times per second.
