Space Dust More Pervasive Than Thought
http://news.yahoo.com/s/space/20090227/sc_space/spacedustmorepervasivethanthought
Andrea Thompson
Senior Writer
SPACE.com andrea Thompson
senior Writer
space.com – Fri Feb 27, 1:33 pm ET
The vast spaces between galaxies might seem pretty empty. But they are actually littered with clouds of cosmic dust that were likely ejected from the galaxies themselves. And the dust scatters farther into intergalactic space than astronomers expected, a new study finds.
The discovery was made by watching subtle shifts in the light emanating from radio sources that sit at the hearts of far-away galaxies.
These radio sources are called quasars, and are the most distant and powerful sources of energy in the universe. From their nests at the center of galaxies, they emit powerful jets of radio waves, X-rays and sometimes high-energy gamma rays. Like celestial flashlights, their light can penetrate through the dark expanse of space.
On its way to Earth, the light from quasars passes by and through intervening galaxies. Dust grains in the galaxies block the light from the blue end of the spectrum more effectively than red light, causing a quasar to appear redder to viewers on Earth.
This same phenomenon can be seen on Earth during a sunset: "Light rays pass through a thicker layer of the atmosphere, absorbing more and more blue light, causing the sun to appear reddened," said Ryan Scranton of the University of California, Davis, who was part of the team that made the dust discovery.
Could this explain Dark Matter? Most theories that I hear are pretty fanciful, something like this could account for the missing mass.
http://news.yahoo.com/s/space/20090227/sc_space/spacedustmorepervasivethanthought
Andrea Thompson
Senior Writer
SPACE.com andrea Thompson
senior Writer
space.com – Fri Feb 27, 1:33 pm ET
The vast spaces between galaxies might seem pretty empty. But they are actually littered with clouds of cosmic dust that were likely ejected from the galaxies themselves. And the dust scatters farther into intergalactic space than astronomers expected, a new study finds.
The discovery was made by watching subtle shifts in the light emanating from radio sources that sit at the hearts of far-away galaxies.
These radio sources are called quasars, and are the most distant and powerful sources of energy in the universe. From their nests at the center of galaxies, they emit powerful jets of radio waves, X-rays and sometimes high-energy gamma rays. Like celestial flashlights, their light can penetrate through the dark expanse of space.
On its way to Earth, the light from quasars passes by and through intervening galaxies. Dust grains in the galaxies block the light from the blue end of the spectrum more effectively than red light, causing a quasar to appear redder to viewers on Earth.
This same phenomenon can be seen on Earth during a sunset: "Light rays pass through a thicker layer of the atmosphere, absorbing more and more blue light, causing the sun to appear reddened," said Ryan Scranton of the University of California, Davis, who was part of the team that made the dust discovery.
Could this explain Dark Matter? Most theories that I hear are pretty fanciful, something like this could account for the missing mass.
Facebook
Twitter
Instagram