otablyGerard Kuiper, tcronomer for s is named,took any interest in tem at all. to  toryin texas, folloer by  t Center in Cincinnati andtc in Arizona, a long list of lost asteroids led doil by tietury only one knoeroid ed for—anobject called 719 Albert. Last seen in October 1911, it racked doerbeing missing for eighty-nine years.

    So from t of vieeroid researcietury ially just along exercise in bookkeeping. It is really only in t fe astronomers o count and keep an eye on t of teroid community. As of July 2001,ty-six teroids ified— to a billion to identify, t obviously has barely begun.

    In a sense it ters. Identifying an asteroid doesn’t make it safe. Even if everyasteroid in tem , no one could say urbationsmigling to forecast rock disturbances on our o t in space and  do is beyond guessing. Any asteroid outt  is very likely to her.

    t as a kind of freeepping off t least 90 percent of trians are quite unknoo us. e don’t kno of en t atsome point, at uncertain intervals, trundle across tsixty-six teven Ostro of t Propulsion Laboratory  it,“Suppose t tton you could pus up all teroids larger t ten meters, ts in t, you  a couple of tant tars, but millionsupon millions upon millions of nearer, randomly moving objects—“all of  courses t different rates. It  ist can’t see it.

    Altoget is t—t is really only a guess, based on extrapolating fromcratering rates on t some teroids big enougo imperilcivilized existence regularly cross our orbit. But even a small aster