WASHINGTON (Reuters) -- The Andromeda galaxy just got bigger -- three times bigger, astronomers said on Monday.
The galaxy is not actually expanding. But new measurements suggest that the nearest galaxy to our own Milky Way is three times broader than astronomers had thought.
They now believe a thin sprinkling of stars once thought to be a halo is in fact part of Andromeda's main disk.
That makes the spiral galaxy, so close to Earth that it appeared as a fuzzy blob to the ancients, more than 220,000 light-years across -- triple the previous estimate of 70,000 to 80,000 light-years.
It appears that the outer fringes of the disk were made when smaller galaxies slammed together, they told a meeting of the American Astronomical Society in Minneapolis.
The structure is too bumpy to have been formed otherwise, said Rodrigo Ibata of the Observatoire Astronomique de Strasbourg in France.
"This giant disk discovery will be very hard to reconcile with computer simulations of forming galaxies. You just don't get giant rotating disks from the accretion of small galaxy fragments," Ibata said in a statement.
Ibata, Scott Chapman of the California Institute of Technology and colleagues in Britain and Australia worked together using observations from the Keck II telescope in Hawaii.
They studied the motions of about 3,000 stars thought to be a mere halo and not an actual part of the galaxy's disk.
But they are in fact sited in the plane of the Andromeda disk itself and move at a velocity that suggests they are in orbit around the center of the galaxy, Ibata's team said.
Andromeda is 2 million light-years from Earth. A light-year is the distance light travels in a year -- about 6 trillion miles (10 trillion km).
Tuesday, May 31, 2005
Friday, May 27, 2005
Bright spot on Titan baffles scientists
Scientists believe the spot might have formed recently as a result of an asteroid impact, landslide or volcanic eruption.
Another Titan flyby in July could determine exactly what the spot is.
Cassini has observed other patches on Titan's surface that usually disappear after a few hours.
The $3.3 billion Cassini mission, funded by NASA and the European and Italian space agencies, was launched in 1997 and took seven years to reach Saturn to explore the ringed planet and its moons.
Scientists think Titan's atmosphere is similar to that of the early Earth and studying it could provide clues to how life began here.
Cassini is managed by NASA's Jet Propulsion Laboratory in Pasadena.
Wednesday, May 25, 2005
NASA seeks oxygen source on moon
(CNN) -- NASA has offered a $250,000 prize to any scientist who discovers a way of extracting breathable oxygen from moondust.
The competition is the latest in NASA's "Centennial Challenges" series, which aims to stimulate the development of technologies useful to space exploration.
To claim the MoonROx prize, scientists must develop and demonstrate hardware capable of extracting at least five kilograms of breathable oxygen from a simulated lunar soil made from volcanic ash in an eight-hour period.
MoonROx stands for Moon Regolith Oxygen -- regolith being the loose layer of rocks and debris covering the surface of a planet or moon.
The MoonROx Challenge was announced by NASA in partnership with the Florida Space Research Institute (FSRI). Entrants have until June 1 2008 to collect the prize fund.
Craig Steidle of NASA's exploration office said that the use of resources on other worlds was a key element in the organization's vision of space exploration.
It hopes the prize could lead to the development of a sustainable source of oxygen that could support permanent lunar bases and provide the fuel for vehicles that will land on and launch from the moon.
Unveiling a new vision of NASA-led space exploration last year, U.S. president George W. Bush said that a moon colony could be used as a "stepping stone" for missions into deeper space.
Bush said the soil of the moon contained "raw materials that might be harvested and processed into rocket fuel or breathable air. With the experience and knowledge gained on the moon, we will then be ready to take the next steps of space exploration -- human missions to Mars and to worlds beyond."
While ways of extracting oxygen from regolith already exist, so far nobody has come close to producing the large quantities that would be needed by NASA.
"Oxygen extraction technologies will be critical for both robotic and human missions to the moon," said FSRI Executive Director Sam Durrance, a former astronaut.
"Like other space-focused prize competitions, the MoonROx challenge will encourage a broad community of innovators to develop technologies that expand our current capabilities."
NASA launched the Centennial Challenges in March in the spirit of past competitions that have fostered technical innovation in the aviation and space industries. In October SpaceShipOne claimed the $10 million X-Prize after becoming the first privately funded spacecraft to successfully reach sub-orbital space.
The first two challenges focused on developing technologies towards building a space elevator that could put satellites into orbit.
"For more than 200 years, prizes have played a key role in spurring new achievements in science, technology, engineering and exploration," said NASA's Associate Administrator for Exploration Systems Mission Directorate, Craig Steidle.
"The innovations from these competitions will help support advances in aerospace materials and structures, new approaches to robotic and human planetary surface operations, and even futuristic concepts like space elevators and solar power satellites."
The competition is the latest in NASA's "Centennial Challenges" series, which aims to stimulate the development of technologies useful to space exploration.
To claim the MoonROx prize, scientists must develop and demonstrate hardware capable of extracting at least five kilograms of breathable oxygen from a simulated lunar soil made from volcanic ash in an eight-hour period.
MoonROx stands for Moon Regolith Oxygen -- regolith being the loose layer of rocks and debris covering the surface of a planet or moon.
The MoonROx Challenge was announced by NASA in partnership with the Florida Space Research Institute (FSRI). Entrants have until June 1 2008 to collect the prize fund.
Craig Steidle of NASA's exploration office said that the use of resources on other worlds was a key element in the organization's vision of space exploration.
It hopes the prize could lead to the development of a sustainable source of oxygen that could support permanent lunar bases and provide the fuel for vehicles that will land on and launch from the moon.
Unveiling a new vision of NASA-led space exploration last year, U.S. president George W. Bush said that a moon colony could be used as a "stepping stone" for missions into deeper space.
Bush said the soil of the moon contained "raw materials that might be harvested and processed into rocket fuel or breathable air. With the experience and knowledge gained on the moon, we will then be ready to take the next steps of space exploration -- human missions to Mars and to worlds beyond."
While ways of extracting oxygen from regolith already exist, so far nobody has come close to producing the large quantities that would be needed by NASA.
"Oxygen extraction technologies will be critical for both robotic and human missions to the moon," said FSRI Executive Director Sam Durrance, a former astronaut.
"Like other space-focused prize competitions, the MoonROx challenge will encourage a broad community of innovators to develop technologies that expand our current capabilities."
NASA launched the Centennial Challenges in March in the spirit of past competitions that have fostered technical innovation in the aviation and space industries. In October SpaceShipOne claimed the $10 million X-Prize after becoming the first privately funded spacecraft to successfully reach sub-orbital space.
The first two challenges focused on developing technologies towards building a space elevator that could put satellites into orbit.
"For more than 200 years, prizes have played a key role in spurring new achievements in science, technology, engineering and exploration," said NASA's Associate Administrator for Exploration Systems Mission Directorate, Craig Steidle.
"The innovations from these competitions will help support advances in aerospace materials and structures, new approaches to robotic and human planetary surface operations, and even futuristic concepts like space elevators and solar power satellites."
New planet found in Milky Way
New planet found in Milky Way
(CNN) -- Australasian researchers have helped discover a new planet in the Milky Way, and they believe it's just a matter of time before more are discovered.
The gaseous planet is about 1000 times the size of Earth and is about halfway to the center of the galaxy, or about 25,000 light years away, researchers said Tuesday.
The project used a little-known technique called micro-lensing -- using the gravitational pull of a star to act as a giant lens -- to help astronomers to look for new planets.
University of Tasmania Professor John Dickey, who took part in the project, told Australia's ABC radio that that the technique could help astronomers discover new planets unable to be picked up by more traditional methods.
"What's special about this event is, it was discovered in a way ... which could, in principle, turn up Earth-like planets as well," Dickey said.
"Our other ways of finding planets around stars are only sensitive to very massive ones like Jupiter.
"We've been struggling with this technique to try to open the door to finding Earth-like planets, which I think is now much more hopeful."
The Hubble Telescope in the United States will now be used to try to find out more information about the star and its planet, which astronomers believe is the most distant ever detected.
The discovery is the result of a project coordinated by the Paris Institute of Astrophysics involving four telescopes in the southern hemisphere, including the University of Tasmania's Canopus Observatory.
The gaseous planet is about 1000 times the size of Earth and is about halfway to the center of the galaxy, or about 25,000 light years away, researchers said Tuesday.
The project used a little-known technique called micro-lensing -- using the gravitational pull of a star to act as a giant lens -- to help astronomers to look for new planets.
University of Tasmania Professor John Dickey, who took part in the project, told Australia's ABC radio that that the technique could help astronomers discover new planets unable to be picked up by more traditional methods.
"What's special about this event is, it was discovered in a way ... which could, in principle, turn up Earth-like planets as well," Dickey said.
"Our other ways of finding planets around stars are only sensitive to very massive ones like Jupiter.
"We've been struggling with this technique to try to open the door to finding Earth-like planets, which I think is now much more hopeful."
The Hubble Telescope in the United States will now be used to try to find out more information about the star and its planet, which astronomers believe is the most distant ever detected.
The discovery is the result of a project coordinated by the Paris Institute of Astrophysics involving four telescopes in the southern hemisphere, including the University of Tasmania's Canopus Observatory.
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