Astronomy — Science as Observation

If you consider the stars in the night sky, you might instinctively think of them as white dots blinking against a dark background. If you live in a city or in an area with a lot of artificial light, it is difficult to see any but the brightest stars, even on a clear night when the moon is not dominating the sky.

But if you are in an area free from city lights and allow your eyes time to adjust to the darkness, after a few minutes of gazing at the sky — and with some concentration — you will begin to see that the stars appear in a variety of colors, from shades of red, orange, and yellow to blue. Their apparent sizes vary, as does their brightness. There is nothing standard at all about the stars.

Remain out in the field or wherever you are for a longer period of time and you will notice change. The position of the stars relative to the horizon or objects like trees or buildings shifts as time goes by. The sky appears to rotate, the stars tracing arcs of motion as the night progresses. Some stars dip below the haze of the horizon while new stars rise above and make their debut. If you were to come out over the course of several clear nights, you might notice a few very bright objects shifting positions relative to the less bright stars, which appear more fixed night after night. With time, you might come to realize these objects are not stars at all, but planets of the solar system, reflecting the light of the sun just as the moon does, rather than shining on their own.

There are puzzles and mysteries to discover in the night sky: colors, motions, and different sorts of objects.

This fascination with the night sky is the ancient human attraction to the science of astronomy. With astronomy, the desire to touch and feel can at times seem frustrating. The objects are too far away, cannot be touched, and can only be seen and observed. The eye is king and light is the muse.

With astronomy, human imagination and creativity soar. Rotate your perspective in your mind and imagine, if you can, your body aligned with the solar system’s axis. Think of yourself aligned with the Earth, the sun, and the planets, and see the orbits from a different perspective than from your feet planted on Earth. If you can, your mind can now zoom about the solar system and see the stars from a new vantage point. You still cannot touch anything, but the light comes to you in a different way.

If the moon is up, have a look at it. It is lit by sunlight — light reflected from the sun, bouncing off the surface of the moon before it reaches your eye. Put your hand out. It is bathed in moonlight. Photons that left the surface of the sun, bounced off the surface of the moon, and then struck your hand. You are touching light that only just now visited the moon. Since the moon is about 384,400 km (240,000 miles) from Earth, and light travels about 299,792 killometers per second (about 186,000 mph), the light touching your hand last touched the moon only about 1.3 seconds ago.

Perhaps you can touch in the science of astronomy, after all. Connected by light, the moon can caress your hand with a message from its surface sent with a delay of only a little more than a second.