About Science
Study reveals why the leopard got its spots
Allergy risk linked to time of first trimester
Hubble reveals furthest galaxy yet
Scientists confirm water from lunar probe
Researchers power up tiny batteries
Plants clean air better than expected
Haiti fault capable of another big quake
Japanese man joins growing genome ranks
NASA releases report into balloon crash
Tree's ability to soak up CO2 has limits
Ground coffee helps robot get a grip
Assassin bugs lure arachnid snack
Research reveals spring in ostrich's step
Lizard gender bends at altitude
Study suggests early primates out of Asia
Flamingos boost their colour to find a mate
Globular clusters more than one-off event
Ancient Africans first to use sharp tools
Grass could turn toxic waste into energy
Earth-like planets may be common
Natural born cell killers
Fingers spot typo ahead of the brain
Ecofriendly styrofoam from milk and clay
Study proves exercise boosts immune system
Fly-by captures first comet photos
A spacecraft has successfully conducted a close fly-by of the comet Hartley 2, providing the most extensive observations of a comet ever.

Comets are thought to be the left over construction debris from the formation of our solar system, yielding important information about the birth of the Sun and planets, 4.6 billion years ago.

NASA's EPOXI spacecraft passed within 700 kilometres of Hartley 2's surface at 0050 AEDT today, providing the first ever close-up details.

Scientists say initial images are giving new information about the comet's size, shape and chemical composition.

EPOXI uses the already in-flight Deep Impact spacecraft which successfully fired an impactor into the comet Tempel 1 in July 2005.

Images from the EPOXI mission reveal Hartley 2 is about 2.2 kilometres long and has a mass of about 280 million tonnes.
Australia key to mission

NASA's Deep Space Communications Complex at Tidbinbilla near Canberra is playing a major role in the mission, being the primary data receiving station for much of the fly-by.

Facility spokesperson Glen Nagle says the comet was 18 million kilometres away when the first data began downloading about an hour after the closest approach.

"Early images show the peanut-shaped space rock in amazing detail. For the first time, we may be able to connect activity to individual features on the nucleus. You can actually see where some of the comet's jets and gasses are spewing from, and the high resolution images are yet to down-load!"

Nagle says there'll be another three weeks of imaging during the spacecraft's outbound journey.
Cometary poison gas geyser

The Hartley 2 encounter is only the fifth time a spacecraft has come close enough to image a comet's surface. The others were Halley, Tempel 1, Borrelly and Wild 2.

EPOXI Principal Investigator Michael A'Hearn from the University of Maryland says Hartley 2, though smaller, is far more active than the others, spewing five times more gas and dust.

He says earlier readings indicate ice, carbon dioxide and silicate dust particles. "But the biggest surprise was a massive surge of cyanide."

Cyanide is a common ingredient of comet cores. But the size and purity of this outburst was unexpected.

"The abundance of cyanide in the comet's atmosphere jumped by a factor of 5 over an 8 day period - that's huge," says A'Hearn. "Curiously, however, there was no corresponding increase in dust."

"This flies in the face of conventional wisdom. Comet cores are thought to be a mish-mash of volatile ices, rock, and dust particles, generally well mixed.

"When the ice evaporates to produce a jet of gas, dust naturally comes along for the ride. Yet this outburst was pure gas."

"The amount of gas suggests a global event - but how could such an event occur without dust? It's a mystery", says A'Hearn.

Hartley 2 is named after its discoverer Malcolm Hartley, who first saw it in 1986 through the Schmidt Telescope at the Australian Astronomical Observatory.

The mission name EPOXI is a combination of the names for the two extended mission components: the Extrasolar Planet Observations and Characterisation (EPOCh), and the fly-by of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI).

Researchers put spark into scramjets
Fish found making their own 'mozzie' nets
Japan confirms asteroid dust on outback probe
Genetech pioneer awarded science prize
Scientists capture anti-matter atoms
Study reveals Icelandic eruption build-up
Astronomers spot galactic intruder
Open-mouthed laughter appreciated most
Financial crisis causes dip in CO2 levels
Puberty genes linked to body fat
Face shields needed for combat: study
Organically-grown vegies not more nutritious
Bloodstains could give age away
Models show pterosaurs flew long, slow
Marsupial carnivores were underestimated
Massive black hole collision revealed
Jet-lag causes long term memory loss
Sunken tanks could detect secret nukes
Dino demise supersized the mammals
Binge drinking linked to heart disease
Cassini sniffs oxygen on Saturnian moon
Image shows echoes from before big bang
Research uncovers diamond's soft side
World warmer, but trends at odds: report
Humans caused megafauna demise: expert
The world: Four degrees warmer
Blood vessels show pollution, heart disease link
Young great whites don't have the bite
Dolphin social network good for calves
Is fish-oil Alzheimer snake-oil?
Cosmic rays trace Sun's journey through space
Marsupial mole mystery solved
Scientists warn of new polio virus strain
Oldest known stone axe found in Arnhem Land
Fly-by captures first comet photos
Dead quasar's ghostly glow reignites debate
Mum and Dad tell us how to wear our genes
New images expand solar flare knowledge
Experts urge caution on Snowy cloud seeding
First little Big Bangs created at CERN
Tarantulas help map the fear factor
Neanderthal brains developed differently
Whales showing more sun damage
Bush cricket has the biggest balls of all
Giant gamma bubbles found in Milky Way
Complex life possible earlier than first thought
Happiness evades wandering minds?
Cat lapping defies gravity
Physics unravels wet dog shake
Hubble captures rare galactic view
Early wrinkles no sign of an early grave
World's forests suffer from 'leakage'