The Lure of the Unexpected
One of the joys of astronomy is the surprising things we see - the lure of the unexpected. This may seem strange for an endeavor that studies the vast, apparently unchanging cosmos. But it is the little things that can really make this special. This essay was inspired by three recent unexpected events in the last two nights. For someone who has been shirking on my observing dues lately, this was a very rich payoff - probably more than I deserved. But, then, the Universe is not a harsh mistress.
The first of these was the appearance of Comet Hale Bopp in the evening sky on March 10. While not totally unexpected, I wasn't expecting it to be this bright, this high this early. There it was, hanging over my neighbor's house in the twilight. What a wonderful comet! Its appearance through a telescope never ceases to amaze me - the condensed nucleus, the shape of the coma, and the marvelous concentric "hoods" surrounding the nucleus! And 130 million miles away still. Wow!
The second and third unexpected joys were this evening (March 11). Both involved the moon. The waxing fingernail moon in the west has looked wonderful the last two evenings with bright earthshine illuminating the dark portions. I could see many of the albedo features including the maria, ray craters such as Aristarchus, Copernicus and Tycho, and dark craters like Grimaldi. While I took a break from Hale-Bopp, I put the scope on the moon to look it over. There, just short of the eastern, dark limb was a relatively bright star. A quick reckoning of the moon's motion told me there would be an occultation. Sure enough, about a minute or two later, it blinked out. Unexpected!
The final of the inspirations occurred just a few minutes ago as I took Shelly, our old faithful dog, out for her evening yard tour. I looked to the west, and that same crescent moon was hanging just above the horizon, the color of a peach. A few minutes later it was duller and lower. Moonrises and sets never fail to inspire the sense of wonder and of the unexpected.
Drew Miller used to tell me that he was drawn to the ephemera of the sky - the unusual, the fleeting, the changing. He would look for asteroids, for comets, for things changing. I can completely agree. What other memorable but unexpected sights come to mind? A bright meteor (truly rare for me), a multiple event graze (you never know how many to expect), the zodiacal light, an aurora, an unusual cloud configuration on Jupiter, an unexpected play of light and shadow on the moon. The list is endless.
In "Soul of the Night", Chet Raymo says: "Let us worship the spine and its tingle," Vladimir Nabokov advised students in his lectures on literature. "That little shiver behind is quite certainly the highest form of emotion that humanity has attained when evolving pure art and pure science." Searching for faint lights in the night sky is both an art and a science, and I count as worth a king's ransom the tingle in the spine that invariably accompanies a rare find. "We are vertebrates," said Nabokov, "tipped at the head with a divine flame." The brain is a continuation of the spine, an accretion of tissue at the top that burns with a pure blue flame, but the wick runs the whole length of the candle. The morning I saw the zodiacal light, I felt the heat of the flame all along the wick.
But the simple truth remains, that you have to go out and look before
you can see these riches of the night.