Hello Space Fans and welcome to Your Sky Tonight, my name is Tony Darnell from Deep Astronomy.space.
Tonight, we are entering the realm of the Fall Skies.
On Sep 21st, the night time became longer than the daytime, which is great news for
those of us looking up and relishing the wonders of the distant universe spinning overhead.
The night skies of autumn bring with it many exciting objects, as we go out earlier each
night to follow the increasing night time hours, the Earth moves into an area of its
orbit, where magnificent constellations come into view.
The mighty constellation of Orion with its untold treasures are made available to us
just after midnight.
It contains a huge stellar nursery - the great Orion Nebula, is visible with your naked eye
on dark nights.
The constellation of Taurus the Bill with the magnificent pleides following him on his
back.
So much is happening in the Fall skies that last well into the darkest winter nights that
there will be much to keep us busy.
Tonight, I want to focus on one of my favorite night sky objects: the Great Galaxy of Andromeda.
Like the Orion Nebula, you can actually see the Andromeda Galaxy with your naked eye if
you’re fortunate enough to live under reasonable dark skies.
It will appear as a large, faint smudge of light in the northwestern skies.
If you’re not lucky enough to live under dark skies, the a pair of binoculars will
definitely allow you to see it.
The way I’ve always found the Andromeda Galaxy is to first find the Constellation
Casseopeia which looks like a sideways M or W this time of year.
Using the top three stars which make up a kind of arrowhead, follow it about a hand’s-width
distance to the east and look for a smudge of light.
The Andromeda Galaxy is very large in the sky, spanning three full degrees in our night
sky.
If we could see all of the galaxy by making it much brighter, it would span six full moons.
Because it is so dim however, we can really only see the center, or nucleus of the galaxy
with our naked eye.
If you’re not using binoculars, you may have to be patient and let your eyes completely
adapt to the darkness and then try to use your peripheral vision to see it.
The edges of your eyes are more sensitive to black and white than the center so looking
askance really helps.
This galaxy is two and a half million light years away and travelling towards the Milky
Way at almost a half a million kilometers per hour and will eventually collide with
our galaxy in about four billion years hence.
This means if we can manage to live long enough, this deep-sky, naked eye object will only
get brighter.