Under the general topic of more than a sane person would want to know, this
coming Monday, April 28, at approximately 8 AM EDT, a new probe to study the
evolution of galaxies will be launched from underneath the belly of a
modified Lockheed 1011. The launch will occur off the coast of Florida, near
the Kennedy Space Center, at 39,000 feet. The new probe is called GALEX
(Galaxy Evolution Explorer). It will launched into a 430 mile-high orbit
aboard a Pegasus rocket. An image of the rocket mated to L-1011 is available
at:

      http://www.orbital.com/images/low/BigL1011orb.jpg

The GALEX satellite is designed to take images of nearby galaxies in
ultraviolet light, simply to obtain an accurate survey of their ultraviolet
emissions. UV radiation doesn't penetrate the earth's atmosphere, thus the
only way to obtain this data is from orbit.

The purpose of the mission is to accurately characterize the UV emissions of
galaxies in our nearby neighborhood so that we can better understand their
characteristics. It is assumed that galaxies everywhere in the universe are
aging in the same fashion, but when we look back any distance (billions of
light-years away), we're not only looking billions of years back in time, but
because the universe is expanding uniformly everywhere, we're also looking at
increasingly red-shifted images. Light that was originally emitted as UV
radiation from very far away galaxies is downshifted into the visible and
infrared simply due to the expansion of space, a process called the
"cosmological redshift."

Because the degree of this redshifted light can easily be accounted for
nowadays, by obtaining a definitive survey of nearby (almost unshifted)
galaxies, we will be able to calculate far more accurately how galaxies age
by comparing the total luminosities of the "old" structures we see near us
and those that are increasingly young, but increasingly redshifted, as we
walk out to the edge of our observable universe.

If nothing else, it is very cool that we are asking these questions -- and it
is at least as cool that we can now do these kinds of things in our attempts
to answer them.

More information about the GALEX spacecraft can be obtained at:

     http://www.galex.caltech.edu/SCIENCE/science.html

Wirt Atmar

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *