SETI [Fwd: Andromeda Galaxy & The Milky Way]


Robert Owen (rowen@technologist.com)
Fri, 24 Sep 1999 17:24:29 -0400


Larry Klaes wrote:

> Since the Hipparcos satellite has determined that
> the Andromeda galaxy (a.k.a., Messier 31) is actually
> 2.93 million light years away, does this buy our very
> distant descendants more time to either move the MWG
> out of Andromeda's way, or get all the life forms out,
> or do galaxies need to merge in order to evolve?
>
> Larry
>
> At 10:34 PM 09/22/1999 -0400, Robert Owen wrote:
>
> >Larry Klaes included in his post TEXT: SPACE.COM E-MAIL
> >today a link to the article "The Milky Way Will Never Be the
> >Same" By Ray Villard dated Sep 21 1999 06:48:16 ET.
> >Note this article is protected by Copyright 1999 space.com.
> >
> >Because of the current focus on Galactic Interactions, and
> >especially the recent discoveries by HST, I decided that
> >it should be reproduced for List members. Implicitly, the
> >article also refers to a number of cosmological issues that
> >of general interest to astronomers.
> >
> >*********************************************
> >
> >In case you don't have enough to worry about, astronomers
> >say the Milky Way -- our home galaxy -- is destined to be
> >involved in a disastrous intergalactic collision. The good
> >news is, it won't happen for another 6 billion years from now,
> >so we have plenty of time to plan.
> >
> >Our Milky Way is 100,000 light-years across and contains over
> >100 billion stars. The neighboring Andromeda galaxy, at least
> >as massive as the Milky Way, is visible in the autumn sky as a
> >small spindle-shaped smudged of light located 2.2 million light
> >years away, but it's headed this way at over one million miles
> >per hour.
> >
> >Astronomers don't know for sure if we're in store for a head-on
> >collision or a mere sideswipe. Future telescopes will make pre-
> >cise enough observations to tell for sure, but supercomputer
> >simulations show the collision will cause the Milky Way and
> >Andromeda galaxy to merge together into a single, giant ellip-
> >tical galaxy. The Andromeda galaxy will likely first swing by our
> >galaxy and then take perhaps 100 million years to make a slow
> >U-turn before plunging into the Milky Way's core.
> >
> >Hubble Space Telescope views of spectacular collisions between
> >other pairs of spiral galaxies in the universe have already given
> >astronomers a preview of what's in store for the Milky Way.
> >The nighttime ribbon and stars and dust that marked the lanes
> >of our Milky Way will begin to come apart under the gravitational
> >tug-of-war between the two galaxies. The sky will grow increas-
> >ingly jumbled with shreds of black dust, glowing gas, and "supe-
> >rclusters" of brilliant blue stars. Cold, black molecular clouds will
> >be compressed and heated until they burst apart in a firestorm of
> >starbirth. Supernova explosions from the most massive of the
> >newborn stars will pepper the heavens with titanic blasts going
> >off like a string of firecrackers.
> >
> >As the stars gravitationally settle into their new home, any hint
> >of the Milky Way and Andromeda as majestic spiral galaxies will
> >be gone. Far-future alien skywatchers will gaze into a rich starry
> >sky and look all the way across space into the brilliant core of
> >our newly formed elliptical galaxy.
> >
> >**********************************************
> >
> >Thanks, Larry, for your help,
> >
> >Bob
> >=======================
> >Robert M. Owen
> >Director
> >The Orion Institute
> >57 W. Morgan Street
> >Brevard, NC 28712-3659 USA
> >=======================

=======================
Robert M. Owen
Director
The Orion Institute
57 W. Morgan Street
Brevard, NC 28712-3659 USA
=======================



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