My Hobby Is Astronomy
I LIVE on the North Island of New Zealand, in the South Pacific. Since I was a youth of 15, I have been interested in astronomy. It is a peaceful hobby that can be as simple or as complex as you wish. Be assured that you do not need to have a degree in physics or to be a mathematics whiz to enjoy astronomy.
Most hobbies require some equipment. So, what will you need? Mainly your eyes. When you first go out into the night from the lighted rooms of your house, it will take ten minutes or so for your eyes to adjust to the reduced light. If you are a city dweller, you may notice the intrusion of street and house lights. What can you do about it? For good results, station yourself in a position shielded from these sources of light.
You will enjoy the best viewing conditions on a dark, cloudless night with no moon. The moon imparts a soft glow to the atmosphere, causing many dimmer stars to disappear. How many stars can you see with the unaided eye? Usually between 2,000 and 4,000. The stars nearer the horizon are more difficult to see because you are looking through a thicker blanket of atmosphere, which results in greater dimming and distortion. It surprises some people that only a relatively small number of stars can be seen with the unaided eye, as there seem to be millions when we first look aloft.
A Star or a Planet?
Seeing a brighter point of light prompts the question, Is it a star or a planet? Stars are light sources, great nuclear engines spewing out their electromagnetic signals into space. They are a great distance from the earth, the nearest—other than the sun—being 4.3 light-years away. Light travels at about 186,000 miles [299,000 km] per second. Because the light from stars travels so far to reach us, it becomes rather feeble. It then must pass through the increasing density of earth’s atmosphere, which bends the light rays this way and that. “Twinkle, twinkle, little star, how I wonder what you are,” says the nursery rhyme, adding a touch of animation to the silent heavens. If it twinkles, it is a star.
Planets, however, only reflect light from the sun, just as the moon does. They are relatively close to us, being fellow members of the sun’s family, the solar system. So planets that can be seen with the unaided eye reflect a light that is steady and unblinking.
Help Is Available
If you would like to venture further, let me tell you of some friends that make my hobby much more enjoyable. The first is a star atlas. My present copy is Norton’s Star Atlas, Revised Edition. It has excellent maps of the heavens, plus information that acquaints the amateur with the vocabulary of astronomy.
My second friend is a planisphere, which consists of two plastic disks, one atop the other, that are attached at the center by a dome. The top disk, with a window in it, can be rotated about the lower one with the star chart printed on it and can be set to the required time and date. You are now able to determine which stars are observable from your vantage point at the hour and time of year and at your latitude. In New Zealand a Philips’ Planisphere can readily be purchased or ordered from many bookshops. When buying a planisphere, you will need to know the latitude of your hometown, north or south of the equator.
Should you buy a telescope? If you pursue this hobby, I suspect that ultimately you will. There are three types—refracting, reflecting, and refracting-reflecting. Visit your public library for books on astronomy and telescopes. It is surprisingly easy to make a reflector telescope yourself. Invest in an inexpensive book on how to make an astronomical telescope. You will find it an interesting project.
Binoculars present a wide-field view of the sky. You can see beautiful star clusters that hang like jewels in the black velvet sky. You can see wisps of clouds that prove to be nebulas, clouds of dust and gas, light-years away in deep space. The glowing band of the Milky Way can be seen from any point on Earth. Also, binoculars are best for sweeping the sky when searching for or observing comets, vagabonds that occasionally steal into our nearby space. Local newspapers may carry weekly articles designed to help you watch the night sky.
Do you own a personal computer? There are some programs on astronomy that a beginner would enjoy, plus some sophisticated ones. I use my computer to store all sorts of information dealing with my hobby. There are also popular magazines on astronomy. From time to time, Awake! prints articles on the subject.
Moon and Planets
Of course, no difficulty exists in locating the moon. When visible, it dominates the night sky. A full moon is indeed beautiful, seemingly sailing from east to west as the night passes toward dawn. Closer observation, with the stars as a guide, reveals that the moon is actually traveling in the same direction as we are, from west to east. Check this out over a period of one or two hours or on two consecutive nights, noting the position of the fixed stars relative to the moon. Because the earth is revolving on its axis faster than the moon is orbiting, we leave the moon behind.
A problem can confront the astronomer when the moon is fuller—too much light. I have always most enjoyed observing the moon when it is 4 to 7 days old or 22 to 24 days old, since the shadows of its mountains and crater rims are longer and sharper. As the moon is the only heavenly body close enough for us to see its permanent surface features with the naked eye, its surface appears different depending on whether you are north or south of the equator.
This holds true for the constellations, or star patterns, as well, thereby making it preferable for you to use maps printed for your hemisphere. Otherwise, they are both upside down and back to front—somewhat confusing, especially to an amateur. It must be mentioned also that an astronomical telescope presents the subject under view as upside down. But where are the planets? First, there are two things we need to know: What are the ecliptic and the zodiac?
The ecliptic is the apparent pathway of the sun on its yearly journey, with the stars as a backdrop. The ecliptic intersects the celestial equator at about 23.5 degrees. The zodiac, which means “circle of the animals,” is an imaginary band that follows the ecliptic some 8 degrees on either side. The sun, moon, and planets that can be seen with the unaided eye are always within the zodiac limits. Knowing you are looking at a planet is evidenced by successive nights’ viewing, as a planet will take up station in a different position in relation to the apparently fixed stars.
But which planet am I looking at? Mercury and Venus will always be to the west in the evening sky and to the east in the morning, never overhead. Venus is rivaled only by the Moon. You no doubt know it as the morning star or the evening star. The planets that orbit the Sun beyond the earth make their trail from east to west. Mars, Jupiter, Saturn, and Uranus are also visible to the naked eye. There will initially be a need to consult some source of information about their position, as they hide among the stars.
The Stars
You will always find the stars to be fascinating points of light. Familiarizing yourself with the constellations can be the start of a new friendship with this awesome handiwork of the Creator.
Some stars are of particular interest to us. One is Sirius; it is the brightest star. It is also a double star, being two stars in orbit around a common center. The second brightest star is Canopus. Spacecraft have used this star to find their position in space and to turn their antennae toward earth to facilitate command communication.
Words of Warning
(1) Astronomy should be a hobby, not an obsession. An excellent rule is, “The Creator before the created.” (2) Never, ever, look at the sun or search the sky anywhere near it with a telescope or binoculars; the penalty may be blindness. (3) Do not believe all that you read. Old books may mislead you, as may unproven theories. (4) Be slow to spend money on equipment, as you may lose interest.
My hobby is an unending adventure of discovery and wonderment. Even living forever in God’s new world, we will not learn all the mysteries of the cosmos. (Ecclesiastes 3:11; 8:17) But it will then be forever fascinating to learn more and more about it.—Contributed.