Wednesday, May 25, 2011

The universe as you've never seen it before!

Smithsonian Science reports:

Today, Wednesday, May 25, astronomers unveiled the most complete 3-D map of the local universe (out to a distance of 380 million light-years) ever created. Taking more than 10 years to complete, the 2MASS Redshift Survey (2MRS) also is notable for extending closer to the Galactic plane than previous surveys - a region that’s generally obscured by dust.

2MASS Redshift Survey Map (click the image for a larger view)

Karen Masters (University of Portsmouth, UK) presented the new map today in a press conference at the 218th meeting of the American Astronomical Society.

"The 2MASS Redshift Survey is a wonderfully complete new look at the local universe - particularly near the Galactic plane," Masters said. "We're also honoring the legacy of John Huchra, an astronomer at the Harvard-Smithsonian Center for Astrophysics, who was a guiding force behind this and earlier galaxy redshift surveys."

A galaxy’s light is redshifted, or stretched to longer wavelengths, by the expansion of the universe. The farther the galaxy, the greater its redshift, so redshift measurements yield galaxy distances - the vital third dimension in a 3-D map.

. . .

The 2MRS mapped in detail areas previously hidden behind our Milky Way to better understand the impact they have on our motion.

(Click the image for a larger view)

The motion of the Milky Way with respect to the rest of the universe has been a puzzle ever since astronomers were first able to measure it and found it couldn’t be explained by the gravitational attraction from any visible matter.

There's more at the link.

That map catalogs more than 43,000 galaxies. Heaven knows how many individual stars are included . . . the number has to be in the hundreds of millions, and if the astronomical theorists are right, they'll have billions of planets circling them.

Kinda puts us in our (very small) place in the universe, doesn't it?


1 comment:

Anonymous said...

You are a bit low on your estimate of individual stars. Each galaxy probably contains about 100 billion (10^11) stars. Multiply by 43000 and you get 4.3 x 10^15 or about 4.3 quadrillion stars. Even the national debt is tiny by comparison.