Every sailor needs to know the sky

[HenryC]

When you see the Southern Cross
For the first time
You understand now
Why you came this way

I learned the sky when I was about 12 years old.  We had just moved out to a brand new housing development way out in the country, and it was surrounded by cow pastures, orange groves and open fields. There were no streetlights, in fact, there was very little artificial lighting nearby at all, for miles around.  I guess there aren't too many places like that any more.

I was already fascinated by astronomy, but I had gotten it all from books.  I was a city kid and really didn't know my way around the night sky.  The first step was to get a planisphere, a cardboard disc with a crude star map printed on it, mounted on a cardboard sleeve with a hole cut in it.  The disc  pivots in the sleeve in such a way that if you match the day of the year printed on the disc with the time of night printed on the sleeve, you get a picture of the night sky through the hole.  There are crude constellation stick figures printed on the map to help you recognize and remember the major ones, and the brightest stars are named.  You hold it over your head so the compass directions printed on the sleeve match up with the compass points, and what you see is a crude but useful representation of the sky on that night, at that time.  It may take you a few minutes before you can match up a distinctively shaped constellation like Orion, Cygnus, or Scorpius, but once you do, you are oriented and it becomes a snap to recognize the fainter, less obvious ones.

Planispheres are cheap, and you can buy one at just about any bookstore or science shop.  They are printed for different latitudes, but if the one you have is ten or fifteen degrees off from your latitude, it will do. Planispheres are also set up for Local Mean Time, which can differ from Standard Time by about half an hour, or even an hour or more during Daylight Savings Time.  But that is still close enough to use them successfully.  As you stay out for several hours, the earth will turn and new stars will rise in the east, and old ones will set in the west.  You will see this clearly by referring to your planisphere, and you can adjust it to the new time, but more important, you will get your first real evidence that the earth is spinning on its axis.  It's not just a diagram in a book any more,  you can actually SEE it happening.  The first time I did it blew me away:  I was now a citizen of the galaxy and I was starting to learn my way around.

Even if you stay up all night, you won't see all the stars on the planisphere, about half of them are hidden by the sun's glare.  But if you go out several times throughout the year, the daytime stars will become revealed as the earth orbits the sun, each star rising and setting 4 minutes earlier every night,  until the whole sky is open to you.  There will be a different sky to study for every season, and your planisphere can dial up your star chart for any hour and date you choose. It will even show you the stars that are out in broad daylight; you won't be able to see them, but you'll know exactly where they are. If you have a one or two hour session once a month with your planisphere (I recommend nights with no moon so you can see more stars), you will have learned the night sky, or at least a couple of dozen constellations and a score or more bright stars by name. Of course, you still won't know the whole sky, you'll just know the stars in your hemisphere.  You will have to cross the equator and spend a year there to learn the sky that is hidden from you by the bulk of the earth. Right at the top of my bucket list is a year in Australia or New Zealand so I can learn the Southern Sky. I already have my Southern Sky planisphere, I can't wait to have an excuse to use it. I have never seen it but I hear the Southern Cross, nestled in the Milky Way right next to the Coal Sack Nebula, is absolutely breathtaking.

There are usually only a few hundred stars printed on the disc, and from any one point on earth you can see several thousand, so the planisphere will only get you started.  But you will never be lost again; as long as you can see the night sky, you'll always be able to figure out which way is north. But more important, you will not just have a map in your head, you willl also have a compass, clock and calendar, one set by the earth and the stars themselves.  Everything up there will make sense.

Once I learned the major landmarks, I needed to be able locate fainter, more obscure stars.  It's impossible to memorize everything up there, so I was going to need a star atlas.  As a kid, I bought a copy of Ingall's "Popular Star Atlas" for $5,  with maps of all the naked eye stars and official constellation boundaries for the entire sky, both hemispheres!  No stick figures here, once you know the basics, they just clutter the field.  I remember it took me a long time to save my allowances to buy the Atlas.  I really wanted Norton's, but it was out of my price range.  Today, there are many excellent star charts available, for every application and level of expertise.  You'll know which one to buy as soon as you're ready for it.

You quickly learn that except for their brightness, and perhaps their color, all stars are the same.  They are all identical points of light.  Some are arranged in pretty patterns, but a star is a star, there isn't much more to look at.  But there's a lot more up there than just stars.  The amateur astronomer with even the slightest optical aid can see clusters, nebulae, galaxies, multiple stars, as well as the moon and planets.  But these objects are often faint, and that's why you need the atlas.  In general, the bigger your telescope, and the fainter the object you want to see, the more detailed your star charts will need to be to locate it.  You can buy one of those newfangled computerized telescopes that will automatically go to any catalogue number or stellar coordinate you punch in, but that's not my style.  I would rather track them down myself.  A bird in the bush is much better than a flock at the zoo.

If you decide to stay with astronomy, you will go through a lifetime of upgrades to your observing equipment.  But when you get started, take the advice of the experts like I did when I was 12 years old.  Save up for a good pair of 7x 50 binoculars.  No matter how elaborate your gear gets, you'll still use that binocular every time you go stargazing, in fact, some things look better in binoculars than anything else and there are hundreds of targets you can go after.  The Milky Way on a dark night is absolutely stunning in a 7 x 50.  And when I head Down Under, that's all I'm taking with me.