[ExI] Scientists Find Solar System Like Ours

BillK pharos at gmail.com
Sat Feb 16 10:17:49 UTC 2008

On Feb 15, 2008 10:12 PM, The Avantguardian wrote:
> It does seem to me that this method could be used to search for other
> garden planets ie. earth-like. One would merely have to restrict the
> search to those stars of a spectral class that would put their life
> zone in the 1.5 - 6 AU range. Perhaps SETI should be coordinating with
> these exo-planet people by following up their discoveries with targeted
> eavesdropping rather than just doing whole sky sweeps.
> I am curious, could microlensing be performed with a galaxy aligned in
> the background instead of another star? Seems to me that that would
> greatly increase the technique's usefulness.

Yes. New distance record just announced.


February 12, 2008
Astronomers Find One of the Youngest and Brightest Galaxies in the
Early Universe

NASA's Hubble and Spitzer space telescopes, with a boost from a
natural "zoom lens," have uncovered what may be one of the youngest
and brightest galaxies ever seen in the middle of the cosmic "dark
ages," just 700 million years after the beginning of our universe.

The detailed images from Hubble's Near Infrared Camera and
Multi-Object Spectrometer (NICMOS) reveal an infant galaxy, dubbed
A1689-zD1, undergoing a firestorm of star birth during the dark ages,
a time shortly after the Big Bang but before the first stars reheated
the cold, dark universe. Images from NASA's Spitzer Space Telescope's
Infrared Array Camera provided strong additional evidence that it was
a young star- forming galaxy in the dark ages.

The galaxy is so far away it did not appear in images taken with
Hubble's Advanced Camera for Surveys, because its light is stretched
to invisible infrared wavelengths by the universe's expansion. It took
Hubble's NICMOS, Spitzer, and a trick of nature called gravitational
lensing to see the faraway galaxy.

The astronomers used a relatively nearby massive cluster of galaxies
known as Abell 1689, roughly 2.2 billion light-years away, to magnify
the light from the more distant galaxy directly behind it. This
natural telescope is called a gravitational lens.

Though the diffuse light of the faraway object is nearly impossible to
see, gravitational lensing has increased its brightness by nearly 10
times, making it bright enough for Hubble and Spitzer to detect. A
telltale sign of the lensing is the smearing of the images of galaxies
behind Abell 1689 into arcs by the gravitational warping of space by
the intervening galaxy cluster.



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