Friday, May 27, 2011

More findings in space




There has been many a news story these past few days from the field of
astronomy.  Here are four of them.

We now have a complete (to the best of our knowledge) 3D model of the visible universe.  This includes 45,000 (!) neighboring galaxies.  The
model was constructed by the tried and true astronomical practice of
measuring “red shift.”  Stars obviously emit light that reaches Earth.
By measuring how much that light has shifted into the red region of
the spectrum during its travels to our eyes (or telescopes, really),
scientists can determine both how far away the star is and at what
velocity it is moving away from us.  Remember, the universe is in a
constant state of expansion.  I wish I could have something original
to add to this report, but I really must echo the sentiments of Karen
Masters of the University of Portsmouth, who was quoted in the article
linked above: “It’s nice to have a complete map of where we live.”


In related news, a distance record has been broken by NASA’s orbital
Swift observatory.  An image recorded in 2009 is now one of the most distant objects humanity has ever glimpsed.  The picture is of an
exploded star at the very edge of the observable universe, so distant
that the detonation might have occurred only 520 million years after
the Big Bang.  Given how long it takes light to cross space to our
tiny planet, that means that what we are seeing probably took place
over 13 billion years ago.  There is of course a rival claim to the
“most distant object” title right now, namely a galaxy discovered by
the Hubble space telescope.  Hubble enthusiasts are no doubt in high
dudgeon from these “record broken” headlines.  I say we let the two
telescopes duke it out like men.


Our Moon once held a body of water the size of the Caribbean Sea, says
a recent study of rocks brought back by the Apollo 17 mission.  This
is casting doubt on the theory that the Moon was formed when a
“Mars-sized object” collided with a primordial Earth and sent a chunk
of our planet into space that would eventually form our lonely
satellite.  While many astronomers are still sticking to this theory,
the vast amount of water now entered into the equation is cause for
both pause and puzzlement.  I would think that the age of the Moon
being older than that of the Earth would be enough to prompt that.


Mars is still in an “embryonic state.”  Latest estimates are that the
planet formed in just under three million years.  That whirlwind
composition period plus the fact that it has avoided sizeable
planetary collisions of any kind have left Mars as a “stranded
planetary embryo.”  I don’t know what this means for the “dead Martian
civilization” theory but somehow I expect Richard Hoagland to have
something to say on the subject.




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