I am not saying it's great news that icy comets the size of small houses rush toward Earth by the thousands every day before disintegrating in the upper atmosphere.
Frankly, the concept scares the jaloogies off me. (Don't ask what jaloogies are. I don't know. Besides, I had mine surgically removed in 1986.)I'm glad I mentioned 1986. That was the year Professor Louis A. Frank, a space physicist at the University of Iowa, first published his now-verified small-comet theory, as it's called. (Understand that anything the size of a house can, in a cosmic sense, be called small.)
You'd have thought Frank had issued the outrageous prophecy that by 1997 the Dow Jones Industrial Average would top 7,000. He was laughed at by the very scientists who say they wait for evidence before drawing conclusions.
Evidence, schmevidence. I'll tell you about how open some scientists were to Frank's theory. The newsletter of the American Geophysical Union - the very society of scientists to which Frank recently (and no doubt proudly) revealed the proof of his theory - once printed a picture of a scientist's dog with a caption labeling the animal as a believer in Frank's small-comet idea.
I have great admiration for scientists. Most of them have nearly as much integrity as the rest of humanity. But a few of them have a tendency to become so invested in some theoretical vision of reality that when something comes along to challenge it they shut down their minds.
Which is why I was so taken by what NASA astronomer Steve Ma-ran had to say about Frank's new proof of his small-comet theory: "Scientists are wrong all the time, but it's rare that so many are wrong at the same time, as apparently they were this time."
What were they wrong about this time? Well, in a 1986 physics journal, Frank proposed - on the basis of pictures taken by a NASA spacecraft called the Dynamics Explorer 1 - that miniature comets were raining on the Earth's upper atmosphere, dumping clouds of water vapor on us as they disintegrated.
Other scientists suggested Frank was seeing things. They said maybe his equipment was messing up. They implied that he was misreading data. They said the dark spots that now have been shown to be small comets probably were technical errors. They said, in effect, "Settle down, Beavis."
Frank licked his wounds but wouldn't give in to his know-it-all scientific colleagues. He was pretty sure he was right, but he needed better proof. Which is what he got when NASA put its Polar spacecraft into operation last year. Polar's equipment produced pictures and other data that clearly show Frank knew what he was talking about.
Snowballs that weigh tens of tons zip toward Earth, five to 30 of them a minute, Frank says. A few thousand miles from Earth, they break up, unleashing clouds of water vapor, some of which falls into the atmosphere.
Frank thinks this might account for much of the water in the oceans and may help explain how Earth became hospitable to plant and animal life. But most of that part is still speculation.
What I most like about this story is what other scientists are saying now. Such as Thomas M. Donahue, a University of Michigan physicist, who was a critic of the small-comet theory. "I'm charmed," he says now. "I'm glad that the guy (Frank), who is a great scientist, has managed to make fools of all of us who said he was seeing things."
Still, it's hard to blame other scientists for what I suspect was wishful thinking. After all, who wouldn't prefer to imagine we live in a gentle world - one that doesn't try to kill us by heaving house-size ice balls at us?