Astronomy - without telescopes

I love astronomy.  I'll get a telescope some day but for now I just like to look at the moon, stars, and planets.  I've got some software (free download) called Stellarium that can be used to find out where things are located and when events are scheduled to happen.  Events such as eclipses, for example.

A year ago in April I saw the occultation of Venus by the moon.  That was awesome.  This morning, the thin crescent moon rising above the storm clouds on the horizon, most of its disk lit by earthlight was particularly beautiful.  But I didn't have my camera with me.

How do you take pictures of the moon?  It's  actually pretty easy.  You need a camera of course.  A tripod is useful but not required unless you are taking pictures of the crescent.  And you should have at least 20x zoom power on your camera.  Since the moon is lit by the sun, it is in daylight.  So set your exposure and f-stop accordingly.  1/125th of a sec to 1/500th of a second is usually fine.  The faster speeds are better at the higher zooms to compensate for camera shake if you are not on a tripod.  If you DO use a tripod it is extremely useful to have a remote shutter release - this eliminates shake from you pushing the shutter on the camera body.  If you don't have one, a trick you can do is use the timed release feature most cameras have.

You have to choose whether you want a pic of the moon or a pic of the surrounding stars/clouds/sky with a really bright moon in them.  But of course with photoshop skills you can copy and paste your moon shot into any sky shot you want  :)

Now, for starry night pictures you must have a tripod.  I'll discuss star tracking motors in a later post.  You also need a camera that has a "bulb" setting where you can open the shutter and leave it open as long as you want.  Keeping it wide open for 10 seconds is usually enough to pick up some stars.  If you leave it open longer than 20 seconds you will begin to see star movement on your picture.  Many people WANT to see the star movement and leave the shutter open for many minutes or hours even.  Makes for some spectacular photographs.  If there is any kind of moon in the sky it will wash out your background - you can compensate for this with shorter exposure times.

I typically keep the ASA speed to 400 or less.  I find that higher ASA speeds tend to generate a lot of noise in the picture.

Here is one of my favorite nighttime pictures.  It is of the Milky Way.  If you know where to look you can see the Andromeda galaxy - it is the farthest distant object still visible with the naked eye - I think it is 2M light years away!