October 2008 - Neighbour Planets

will outshine Jupiter in the western skies shortly after sunset.  In September Venus began a seven month tour of the evening skies and will rise higher in the West in the weeks ahead.  Hundreds of years ago, careful observers of these heavenly bodies must have wondered about this apparently bright star and its unusual behavior.   Unlike other stars and planets, with the exception of elusive Mercury, Venus never spends more than a few hours each evening or morning in the dark sky.  With binoculars or a small telescope you can observe phases of Venus similar to phases of the moon.   In the months ahead you will see Venus similar to a half moon and eventually as a bright crescent as it approaches the earth.   At that time, like a new moon, the sun shines mostly on the side of Venus facing away from earth.  The unusual behavior and appearances of Venus are now understood from its unique position of orbiting closer to the sun than the earth.    Someone living on Mars would see earth with similar behavior since earth orbits closer to the sun than Mars. 

Several celestial splendors grace the morning skies before sunrise in October.   It is the best month of 2008 to spot elusive Mercury which never strays far from the sun.  The geometry of our solar system allows Mercury to rise relatively high above the horizon in the morning sky in mid to late October.   If you take a morning stroll before sunrise, you will also have an opportunity to see Saturn as it has now emerged from behind the the sun.  While Saturn dominated last spring’s evening sky, it will not shine as brightly as we now view its rings almost “edge on.”  The morning sky also features the famous constellation, Orion, which we tend to think of more as a winter constellation.   On the morning of October 17 the waning moon will pass in front of the bright Pleiades star cluster.   If you can watch with binoculars, stars will wink “on” and “off” as the moon slowly blocks bright stars and uncovers others in its movement.

    Have you ever seen another galaxy?   All of the stars that we can see with the naked eye belong to our own Milky Way galaxy.   While we can only see a few thousand stars in our galaxy, there are likely over 100 billion stars in the Milky Way.  But from a dark location, away from our light polluted cities, you can see the distant Andromeda galaxy as a small smudge of light.   Most people would not even take notice of it due to its faintness.   But with a small pair of binoculars you can see the 200 to 500 billion stars of Andromeda like a faint cotton ball on a black velvet night sky.  However, the light that you see this month began its journey to your eyes over 2 million years ago.  But what a splendid feeling to know that, after such a long journey, you can be there to welcome its light upon arrival to earth.  While not nearly as impressive as a view of our moon or a planet, a view of a galaxy takes us across vast regions of space to view a massive collection of stars as it appeared several million years ago. 
    October invites us outdoors to marvel at the beauty, majesty and splendor of our solar system, our galaxy and our universe in which we live.