Possible Miniature Solar System Discovered

[Gold9472]

Possible Miniature Solar System Discovered

http://news.yahoo.com/s/ap/tiny_solar_system;_ylt=Aq2hTcYisW6P2tM3ojCYBXes0NU E;_ylu=X3oDMTA2Z2szazkxBHNlYwN0bQ--

36 minutes ago

LOS ANGELES - Astronomers have discovered what they believe is the birth of the smallest known solar system. Peering through ground- and space-based telescopes, scientists observed a brown dwarf — or failed star — less than one hundredth the mass of the sun surrounded by what appears to be a disk of dust and gas.

The brown dwarf — located 500 light years away in the constellation Chamaeleon — appears to be undergoing a planet-forming process that could one day yield a solar system, said Kevin Luhman of Pennsylvania State University, who led the discovery.

It's long been believed that our own solar system came into existence when a huge cloud of gas and dust collapsed to form the sun and planets about 4.5 billion years ago.

The new finding is the smallest brown dwarf to be discovered with planet-forming properties. If the disk forms planets, the resulting solar system will be about 100 times smaller than our own, scientists said.

Brown dwarfs, which are bigger than a planet but much smaller than a star, are thought to be balls of gas that failed to collect enough mass to start shining.

The discovery was made using NASA's Spitzer Space Telescope and Hubble Space Telescope as well as ground observatories. Results will be published in the Dec. 10 issue of the Astrophysical Journal Letters.

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On the Net:

Spitzer Space Telescope: http://www.spitzer.caltech.edu

Hubble Space Telescope: http://hubble.nasa.gov

[Partridge]

Radar sees ice deep below Mars
BBC (http://news.bbc.co.uk/2/hi/science/nature/4479612.stm)



http://newsimg.bbc.co.uk/media/images/41075000/jpg/_41075120_crater_esa_203.jpg Two radar passes revealed a buried Martian impact basin

Mars Express has become the first spacecraft to detect reserves of water ice beneath the surface of the Red Planet, experts have announced. The Marsis radar experiment carried onboard appears to have discovered water ice more than 1km below ground.

It is thought the greatest reservoir of retained water on Mars could be found beneath the surface, perhaps providing a habitat for microbial life.

The US-European Marsis team report their findings in the journal Science.

Underground layered deposits at the planet's north pole have an upper unit thought to be dominated by water ice. This water ice is believed to be nearly pure, with only about 2% contamination by dust.

Beneath this ice layer is a lower unit containing sand cemented with water ice.

Buried crater

Marsis data from Chryse Planitia, in Mars' northern equatorial region, reveal an almost circular structure about 250km across that the authors propose is a buried impact basin.

Chryse Planitia is thought to have been shaped by the outflow of floodwaters from the Valles Marineris region and other areas of the northern highlands.

The radar should be able to detect liquid water if it exists in that form beneath the Martian surface.

"We have found no convincing evidence of liquid water yet," said Jeff Plaut, Marsis principal investigator at Nasa's Jet Propulsion Laboratory.

The science team will begin using the radar experiment to search for liquid water in late December.

Marsis will collect data from the southern polar region and mid-latitude regions during this period of science operations, which will last until March 2006.

The Mars Advanced Radar for Subsurface and Ionosphere Sounding (Marsis) is a collaboration between scientists in Europe and the US.

Two 20m-long (65ft) hollow fibreglass "dipole" booms comprise the instrument's primary antenna, while a 7m-long (23ft) "monopole" boom acts as a receive-only antenna.

Marsis sends out pulses of radio waves from the primary antenna to the planet's surface and analyses the time delay and strength of the waves that return.

Analysis of those waves that penetrate the soil and bounce back give information on transitions between materials with different electrical properties, such as rock, ice and liquid water.