NASA will push back the launch of a next-generation rover to Mars until 2011 because of testing and hardware challenges.

"We will not lessen our standards for testing the mission's complex flight systems, so we are choosing the more responsible option of changing the launch date," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington, in a statement.

Officials with the Mars Science Laboratory say the voyage was initially scheduled for October 2009, but had been postponed two more years to conduct more tests.

The mission will focus on a Mars location where experts believe wet conditions may have existed.  The rover will check for data to determine whether the planet could support life.

By Brett Molina

A Barbie-doll figure may be bad for your health, says a new study in the journal Cultural Anthropology.

The hormones that do a lot of great things -- make women strong, competitive, and able to deal with stress -- also happen to move fat from the hips to the waist, the study says.

It's a trade-off.  Thin-waste figures are associated with some health benefits, including higher fertility and lower rates of some diseases.  But a women with more cylindrical figures may be better able to support themselves or withstand tough situations, says University of Utah researcher Elizabeth Cashdan.

That may be why men in countries with more social equality, such as Denmark and Britain, tend to prefer more cylindrical body types.  In countries with less, such as Japan, Greece, and Portugal, a thin waist is more desirable, the study says.

By Michelle Kessler
Photo: John McHugh/AFP/Getty Images

Most seniors say they feel 13 years younger than they are ... How to safely destroy an asteroid ... The truth about cats and dogs' evolution ... Fossil belonging to new flying reptile species discovered ... Mystery over clouds on Venus solved ... Researchers study why some men prefer to pay for pleasure ... Could another tsunami strike Indonesia? ... Finally, underwater currents could become next source of energy.

By Brett Molina

This new photo, taken by  La Silla observatory in Chile, shows a stunning view of Omega Centauri.  This cluster is thought to contain 10 million stars, and is located in the Milky Way about 17,000 light years from earth.

Omega Centuauri is visible with the naked eye as part of the southern constellation of Centaurus.  But you need a professional telescope to get a view like this.

The star cluster, which was observed by  Ptolemy, is thought to be around 12 billion years old.  New research suggests that there might be a medium-sized black hole somewhere in the middle.

By Michelle Kessler
Photo: European Southern Observatory

Antarctica hosts more species than the Galapagos ... Europe invaded by super-ants ... Learn how our brain remembers important information ... U.N. scientist urges world to tackle "space threat" ... Scientists push to unify research on movement ... Tickets to space just got cheaper, sort of ... Marine animals may use magnetic fields to migrate ... Finally, an ancient insect imprint is discovered in Massachusetts.

By Brett Molina

Swedish researchers induced an "out-of-body" experience in study volunteers, tricking them into perceiving the bodies of other people and mannequin dummies as their own.

"The participants has a sensory experience of having a new body. They of course realize that it is an illusion, but they can't think it away," says study head Henrik Ehrsson of Sweden's Karolinska Institute.

In five experiments reported in the PLoS One journal, researchers tricked volunteers into perceiving a dummy's body as their own and another person's body as their own.

Cameras that made the volunteers see from the vantage of the other person or mannequin, combined with simultaneous contact to the volunteer's skin and that of the mannequin or other person, created the perceptual illusion, the study concludes. Volunteers felt they were shaking hands with themselves in one study.

"The bodily self is identified by a certain relationship between the interior, 'first- person' perspective on the body -- the way the body feels from the inside -- and the exterior, 'third-person' perspective on the body -- the way the surface of the body looks or feels," says Princeton's Mathew Botvinick, who has reported previous experiments that made people perceive a rubber hand as their own.

The study authors hope their findings assist in perfecting remote robotics operations and patients with sensory disorders.

"The thing is that we are probably always a bit out of our bodies but normally the discrepancy is so small that we do not notice it and it does not disturb the way we interact with the world," Ehrsson says, by email.

"These discrepancies between sensation and the physical reality are of course greatly exaggerated in our experiments."

By Dan Vergano
Photo: Valeria Petkova, center, of the Karolinska Institute in Stockholm and Karolinska Institute student Andrew Ketterer, left, test the 'body-swap' illusion. (By Niklas Larsson, AP)

Airline traffic worldwide will more than double by 2025, with jet fuel emissions adding to global warming, suggests an energy policy analysis.  Airlines today carry more than two billion passengers and 41 million ton of freight yearly, note Andrew Macintosh  and Lailey Wallace  of the Australian National University in Canberra, writing in the current Energy Policy journal.  Those numbers expected to increase 110% by 2025.

"While aviation is not currently one of the main drivers of global warming, the growth trajectory of the industry suggests it could become a significant factor over the coming decades," the authors conclude, based on jet fuel emissions of carbon dioxide. Carbon dioxide is the most-noted greenhouse gas released by burning fossil fuels, which the Intergovernmental Panel on Climate Change last year found would "very likely" raise global average temperatures from 3 to 7 degrees Fahrenheit by 2100, by best estimate.  To keep jet fuel emissions to 2005 levels, engine efficiency would have to increase 65% by 2025,  which the authors find "unlikely."

Finding a silver lining to Wall Street's woes, the study concludes, "emissions are likely to increase significantly unless there is a major global economic downturn or other shock to the aviation market. "

By Dan Vergano

Experts' reassess views on Earth's early years ... Are abnormal brain rhythms to blame for disorders like Parkinson's disease and depression? ... Learn how inner ear sensors key to hearing are created ... Stone Age sculptures unearthed in Russia ... Memories likely stored on your DNA ... NASA no longer listening for Mars Phoenix lander ... Finally, a clue to how turtles got their shells.

By Brett Molina

Scientists create genetically-modified peanuts to curb allergic reactions ... Research teams conduct first census of life at the poles ... Could humans rewind the Earth's evolutionary clock? ... Surgeons, now in pill form ... Some brains might be wired for change ... Why so glum?  Planets, crescent moon to put on its "unhappy face" ... Take a look at fragments from the meteorite spotted last week in western Canada ... Finally, the race is on for more fuel-efficient cars.

By Brett Molina

A single smallpox vaccination can be effective for as long as 88 years, says a new study in The American Journal of Medicine.

Smallpox, an often-fatal virus, was eradicated in the wild in the late 1970s.  Since the virus was no longer a threat, production of the vaccine slowed.

But there are fears that bioterrorists might create smallpox in the laboratory and use it as a biological weapon -- and that there wouldn't be enough vaccine to go around.

The new study suggests that adults who were vaccinated at any point in their lives would still be immune to the disease. Only the younger population -- mainly people under 35 -- would need the shot.  That makes it much easier for governments to keep a sufficient supply on hand.

By Michelle Kessler
Photo: A nurse holds a vial of smallpox vaccine enough to inoculate 100 people. (Mike Nelson/AFP)

On Sunday and Monday nights, skywatchers in the Americas will be able to see a close pairing of Venus and Jupiter. As you look southwest, they will appear to be separated by only the width of your finger, according to the editors at Sky & Telescope magazine. And on Monday night, the crescent Moon will also appear in close proximity. Appearances are deceiving, as the planets are far from us and far from each other. The moon is 252,000 miles away; Venus is 94 million miles away; and you'd have to go 540 million miles to hit Jupiter, the magazine says. Venus and Jupiter won't appear this close together in the night sky again until 2013.

By Sue Kelly

The equation that may save the world's threatened ice shelves: rate of spreading * width of the shelf * thickness * a constant.

This simple piece of arithmetic is expected to help glaciologists better understand where and when an glacier will calve, or send a sheet of ice crashing into the sea.  That will improve climate models and generally help scientists understand the impact of global warming.

The math may look easy, but arriving at it was an intricate process involving researchers from several universities, including Penn State, the University of Washington, and the University of California Berkeley. Their work was reported today in the journal Science.

Many variables determine whether a glacier will break or not, but the most important is how quickly the ice sheets spread, the researchers said.  Fast spreading creates stresses that make ice more vulnerable to cracks.

By Michelle Kessler
Photo: An approximately hundred foot slab of Ice falls from the face of the Margerie Glacier in Glacier Bay National Park, Alaska, on Friday, June 9 2006.  (Scott M. Lieberman/AP)

Today's students struggle with science questions from the 1960s...Winning the Nobel Prize has its perks, including free movie screenings...Downey, Calif. tries to reclaim its space-age past...Sperm supply tied to competition (when faced with romantic rivals, mice make more)...Big mouths are a drag for humpback whales...Genes linked to leukemia relapses.

By Michelle Kessler

Thanksgiving in space is stiff turkey, bland yams...The European Space Agency plans to open a research center in the United Kingdom...Association wants the United Nations to have an asteroid policy...An amateur astronomer has spotted an astronaut's tool bag that floated off into space...Iran has launched a rocket into space...European bluefin tuna management called a "mockery of science"...Gene test could predict colon cancer's return.

By Michelle Kessler

A fireball seen over Canada last week was a 10-ton meteorite hurling towards earth, scientists say. 

The desk-sized asteroid fragment streaked through the skies above Lloydminster, a city on the Alberta/Saskatchewan border, on November 20.    Tens of thousands of people saw a bright light cross the sky for about five seconds.  It was also captured on security cameras.   Check out the incredible footage gathered by a Canadian television station.

Now scientists have use that footage to calculate the meteorite's size -- and where its remnants might be found.  University of Calgary researcher Alan Hildebrand predicts that chunks are likely to be discovered in the an area marked on this Google Map.  He's out looking for pieces, which may be the size of football or larger.

By Michelle Kessler

The Hubble Space Telescope has captured this incredible image of two powerful but elusive stars,  WR 25 and Tr16-244.  Located 7,500 light-years from Earth, these stars emit powerful amounts of heat and radiation.  But they're so far away that they've been tough to get a good look at -- until now. 

These bright stars burn through their hydrogen fuel sources very quickly, creating a "live fast, die young" lifestyle, the European Space Agency says.

The stars are part of the Carina constellation. 

By Michelle Kessler
Photo: NASA, ESA and Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain)

Researchers buzzing over "exciting" form of dark matter ... Would robots fare better as soldiers on the battlefield than humans? ... Key ingredient to planetary formation discovered ... Astronomers capture galaxies in their awkward years ... Scientists create a "roach motel" for bad bacteria ... A family affair: Amoebas turn to kin during tough times ... Man crosses gorge in Colorado with a jet pack ... NASA plans return trip to Jupiter ... Finally, how the hair on a horse's head could help racing trainers.

By Brett Molina

Orion the Hunter appears to be firing his arrows at Earth, report international researchers who have detected an excess of cosmic rays coming from the starry constellation.

Cosmic rays are high-energy particles thought to be ejected from exploding stars. An international team, led by Jordan Goodman of the University of Maryland, describes the impact of the collisions of 200 billion cosmic rays from throughout space with Earth's atmosphere recorded in the last seven years. The study, published in the journal Physical Review Letters, uncovered the cosmic ray hotspots that appear to come from the direction of Orion.

"This discovery calls into question our understanding of cosmic rays and raises the possibility that an unknown source or magnetic effect near our solar system is responsible for these observations," says team scientist John Pretz of the Los Alamos National Laboratory in a statement. Astronomers had previously supposed that cosmic rays originate uniformly from all sources in space.

By Dan Vergano
Photo: Cosmic ray hotspots (By John Pretz, Los Alamos National Laboratory)

Global plan seeks to recharge hopes for fusion power ... Endeavour astronauts prep for final spacewalk ... DInosaur footprints found in Wyoming and the U.K. linked to similar species ... New technique could reveal more about universe's most abundant form of matter ... Designing the ultimate golf ball ... Physicist bringing mathematical science instruction to Africa ... Finally, lost and found: Satellite tracker captures toolbag lost by astronauts on video.

By Brett Molina

European astronomers have released a tentative photo of another planet orbiting a nearby star, hard on the heels of last week's announcement of similar discoveries by North American teams.

The latest image comes from Beta Pictoris, a young, massive star about 70 light years away, close by galactic standards (one light year is about 6 trillion miles.) French observers using the European Southern Observatory's Very Large Telescope report detecting a planet about eight times heavier than Jupiter in infrared images taken of the star.

"When confirmed, this ... will be the closest planet from its star ever imaged," says a statement from the intergovernmental ESO. The planet is as close to its host star as Saturn is to the Sun.

Scientists last week released the first snapshot of a distant solar system, one with three orbiting planets larger than Jupiter. Another team of astronomers released images of single giant planets orbiting nearby stars.

By Dan Vergano
Photo: Beta Pictoris seen in infrared light (European Southern Observatory)