For budding time travellers, the future (or should that be the past?) is starting to look bleak. Hypothetical tunnels called wormholes once looked like the best bet for constructing a real time machine. These cosmic shortcuts, which link one point in the Universe to another, are favoured by science fiction writers as a means both of explaining time travel and of circumventing the limitations imposed by the speed of light. But the idea of building these so-called traversable wormholes is looking increasingly shaky, according to two new scientific analyses.
'Perfect' spiral galaxy may harbour dark secret
(May 23, 2005)
A picture-perfect spiral galaxy may harbour two colossal black holes instead of the usual one, new observations suggest. But if it does, astronomers are mystified as to how the second black hole got there without ruining the galaxy's spiral structure. Most galaxies are thought to contain a single large black hole with a mass proportional to that of its galaxy. But galaxies grow through collisions, and astronomers believe their black holes also merge over time. A trio of astronomers, led by Damián Mast of Argentina's National University of Cordoba, says there may be two black holes inside the galaxy M83, which lies about 15 million light years away.
A previously unknown monkey species has been found in the mountains of southern Tanzania. The animal is believed to be a critically endangered species, with no more than perhaps a thousand individuals remaining. The highland mangabey, as it is called, lives in the trees and is thought to be closely related to the baboon family. Full details of the discovery were revealed on Thursday in the journal Science.
Bush likely to back weapons in space
(May 19, 2005)
President George Bush is expected to issue a directive in the next few weeks giving the US Air Force a green light for the development of space weapons, potentially triggering a new global arms race, it was reported yesterday. The new weapons being studied range from hunter-killer satellites to orbiting weapons using lasers, radio waves, or even dense metal tubes dropped from space by a weapon known as "Rods from God" on ground targets.
A spider relative called a harvestman trapped in amber could shed light on how arachnids were affected by the extinction that wiped out dinosaurs. The 100 million-year-old arachnid, which looks like it might have died last year, wandered though a dinosaur-dominated world. Though older fossils exist, hardly any are known from the Mesozoic Era (245 million-65 million years ago).
Efforts are under way to restore part of Siberia to the way it was more than 10,000 years ago, before the end of the last ice age. The "Pleistocene Park" experiment will try to turn the wet, boggy tundra back to the dry grasslands that once were home to large herds of stampeding mammals. These creatures included bison, horses, reindeer, musk-oxen, elk, saiga, and yaks and even woolly rhinos and mammoths. There were top predators, too, such as cave lions and wolves.
Canadian satellite plays hide and seek with exoplanet
(May 17, 2005)
MOST, Canada's first space telescope, has turned up an important clue about the atmosphere and cloud cover of a mysterious planet around another star, by playing a cosmic game of 'hide and seek' as that planet moves behind its parent star in its orbit. The exoplanet, with a name only an astrophysicist could love, HD209458b (orbiting the star HD209458a), cannot be seen directly in images, so the scientists on the MOST (Microvariability & Oscillations of STars) Satellite Team have been using their space telescope to look for the dip in light when the planet disappears behind the star.
Read more. Source: Spaceflight Now/Univ. of British Columbia
Stars spotted on the edge of a massive black hole
(May 16, 2005)
A group of young stars has been spotted dangerously close to the giant black hole at the centre of our galaxy – only the second such group known to be braving the region's extreme conditions. Two years ago, astronomers found the first cluster of young stars 0.7 light years from the black hole. How they got there is unclear, because the black hole's gravity ought to tear apart the clouds of gas and dust from which new stars form. The latest group of five young stars, found by Jessica Lu of the University of California in Los Angeles and her colleagues using the Keck I telescope in Hawaii, is moving in convoy even closer to the galactic center – just 0.26 light years away.
Two oddities on Saturn's moon Iapetus could have a single cause. One hemisphere is much darker than the other, and a huge ridge on the equator on the darker side makes the moon look rather like a giant walnut. Both these mysterious features could be the result of an ancient dust-up between the moon and one of Saturn's primordial rings. At least, that's the conclusion radio astronomer Paulo Freire came to after looking at pictures of Iapetus taken by the Cassini spacecraft at the end of last year.
NASA is looking at other options for completing the International Space Station if it is not finished by the time the shuttle retires in 2010, the head of the US space agency has said. "The shuttle is inherently flawed. It does not have an escape system for its crew," NASA chief Michael Griffin told a Senate oversight committee. "We all know that since human perfection is unattainable, sooner or later there will be another shuttle accident," he said. "I want to retire it before that flight can occur."
