In July 2009, out of the black, a large object hit Jupiter, catching professional astronomers with their elevations down and their azimuths askance. In spite of the billions we spend on government pro- grams to gaze at the heavens, the event was discovered by an amateur astronomer in Australia using his homemade tele- scope. When he alerted the professionals, they quickly pointed a few of our large taxpayer-funded telescopes at Jupiter, get- ting some fine (if late) images, and letting us know that our money was being well spent.
As one of those taxpayers, I find it bothersome that the most justifiable use of public money for telescopes – trying to give us early warning of astronomical objects that might destroy us – is one use those telescopes rarely get. Instead, astronomers book telescope time months or years in advance, the vast majority of the time to look at narrow sectors of far- away corners of the universe.
After the Shoemaker-Levy comet hit Jupiter in 1994, more people started wondering about the likelihood of an impact on earth. So astronomers sat down at their government- funded computers and started figuring. Estimates had to be made about the size and number of roaming space objects that might do serious damage. “Let’s see, if we overestimate the amount, people will think that we’re crying wolf. On the other hand, if we underestimate, our funding won’t be viewed as critical.” Their answer: Jupiter will be hit an average of once every few hundred years. Some said every few thousand. The earth, being much smaller than Jupiter, has significantly less chance of being hit. Obviously, with an answer that vague, there was a lot of guessing involved. And now it seems likely that the guesses were low.
I’m sure we’re about to hear warnings that the risk of impact to us is much greater than originally predicted and that we should spend even more tax money on even more telescopes. But the evidence suggests to me that if we let people keep their own money to spend on the leisure activities of their own choosing – like say, backyard astronomy – that we can get much more useful information for free.