Expert: Tom Whiting - 12/25/2007

Question
Hello,
My question pertains to the numerous images that we, the layman is shown of deep space objects such as nebula's, galaxies. What I find intriguing is that all of these are seem to have enormous size but the experts describing them make no mention of their orientation in space, or for Earth for that matter. I mean, where exactly do we or any of the objects viewed by man stand in the universe, i.e., north, south, east west etc. I would certainly appreciate it if this concept is discussed in detail...
thanking you

Answer
Hi Arsalan,
Good question, but difficult to answer, as you'll see below. Well, first, all those pretty deep sky
objects are very magnified through a telescope, and they
vary in both the "size" we see them from Earth, and their
real size way out in space.  It all varies, for instance
the Great Nebula in constellation of Orion M-42) is several hundred lightyears across, but it's 1500 lightyears distant, so we on Earth see it as a naked-eye
object about 1/20 a degree across (about one tenth the apparent size of the full moon).  The Lagoon Nebula, M-8 is naked eye too, and it's about 1/2 degree across, but it's much bigger, fainter, and much farther away.  And still galaxies are much much farther away, millions of lightyears in fact, but they are huge by comparison, like our own Milky Way is about 100,000 lightyears in diameter.

Most of the photographs either have north up and east to the right (as we see them naked eye in the sky) or sometimes they are inverted with north at the bottom and east to the left (as we usually view them inverted through a good astronomical telescope).  Sky directions like west, north, etc. are not given because....as the Earth rotates, AND revolves around the sun, the position of the object relative to the sky compass directions, are always changing, so it's no help to state a direction, which would be different in just a few hours, or a few weeks as we orbit the sun.  Instead, for astronomers, it's good enough to just mention the constellation, and then we can find it from there on our star atlases (maps of the sky). {Sailors of the seas need top-notch charts, and so do "Sailor's of the stars")...so get a good star atlas as a very first thing to do. Learn how to use it...you cannot purchase a star chart that is TOO good. Get serious with it, and learn how to use it.}

Usually the constellation that the object is in - - is given, if not, you can always Google it. But first you have
to know your constellations...there are about 40 of them
in the Northern Hemisphere. It's the same for states and cities, isn't it?
Find the town of Guymon...

You have no idea where it's at, do you?  But, let me give you another piece of information...the state (constellation) it's in is Oklahoma.  NOW you've got a much better chance of finding it on a road map.  Still can't?  Well, here is another piece of information, it's nearly in the middle of the Panhandle of Oklahoma!  NOW you can find it on a map. You could even travel there if you wish, now.   We astronomers do exactly the same thing with constellations, as we have most all of them memorized.  I tell a relatively new astronomer to go find the Butterfly open cluster M-6.  This is not much help as it's a Big Sky out there...so I tell him it's in Scorpius.  This narrows the area of sky to search, but not enough for a newbie, so I tell him it's right above (north of) the Scorpion's "tail end stinger stars"  (equivalent to the Panhandle of Oklahoma).  NOW he can find it. AND, now he can travel there too.....not literally, but he can put his telescope on it and look at it, because now he knows where it is in the night sky....and like the town of Guymon, it's always in that same position relative to the
stars, all the time- at least during our short lifetimes!
So once you look at M-6 several times, you simply memorize
it's position in the sky, and soon you don't need the star
atlas anymore to find it.  (Once you've been to the local
food market and the post office to mail a letter, 3 or 4
times, you don't need a map to get there anymore, do you?
It's exactly the same with us astronomers!!
However, most of us experienced astronomers know exactly
from lots of experience, where almost everything important
is...but this takes time and experience to do.  Just like,
if you were a real map freak and crazy about geography, and you had every town of any size in the state of Oklahoma already memorized, you would have known right away where the town of Guymon was located. That's how well
we (and you have to also, to find things) know the night sky.  Heck, I know the night sky better than the streets and office buildings of my own home town!! Because I'm really crazy over astronomy!  Fortunately, or unfortunately, that's how it works, and I see no way
around it...you have to learn the naked-eye night sky first, and get a star chart.  Don't get a scope right
away, because in our great hobby, equipment comes LAST, not
first.  Knowledge comes first....night sky knowledge.
Because if you can't first point your finger to the Great
Nebula in Orion, the Pleiades open star cluster, the Lagoon
Nebula (all naked-eye objects) how are you going to point
a small field of view scope toward them?  You can't, so
basically any scope is worthless to you, until you know
some of the naked-eye night sky.  Sorry, but that's the way
it works in our hobby.
So in conclusion, all those objects are out there in space,
and they are all stationary, relative to the stars, in their "state" or constellation area. And it's up to YOU to learn where they are exactly....we can't lead you to
them with a simple, Oh, it's north or east...that tells
us (and you) nothing; just like the town of Guymon...you have to do the finding yourself.
Oh, one other important thought....all those colors of those photographs...are basically fake.  Well, not really fake fake...but it's the way film and computers see the object, the different wavelengths of light as recorded on film or computer.  Those devices can take a time exposure...gather lots of light for hours and hours.  Our
eyes can't do that, our retina's are wiped 'clean' like
30 times a second, so we see very little color through our
scopes...they are all kind of creamy white, with just a
tinge (or hint) of color.  Most newbies are very disappointed when they view their first object..."Where's all the color"?  Sorry, it doesn't work that way....only film and the computerized pictures can capture all that color and those wavelength's of light; our eyes, our night
vision is not set up to do that. Just a hint of color,
and that's it.
Just thought you'd like to know...
And hope all this helps,
Clear Skies,
Tom Whiting
Erie, PA

FOLLOW UP:
Oh, another way to go here, is to get a computer program
of the night sky, like Google Earth also has a complete
chart and atlas of the night sky with most of the better objects located, and you just click your mouse on them. You can even ask it where any object is located, and it will take you right to that object, and show you where it's at!!

Another good one I use is the free software called "skyglobe"....you can ask it to find things too!
With that program you can view tonight's sky, or the sky
of 2000 years ago, or 2000 years in the future.
Then once you have the chart of the night sky on your
computer, it will help you to learn the sky, and learn
where all those objects are at in the night sky, relative
to the naked-eye stars around them.
I don't know why I didn't think of all this before, but
now you know how to do it, and it's probably the easiest way.
Hope this helps,
Clear Skies,
Tom Whiting