dipper@utastro.UUCP (Debbie Byrd) (08/24/84)
At least one astronomer believes that a swarm of objects in space occasionally encounters the Earth and moon. More on the possible existence of the Canterbury Swarm -- right after this. August 17 The Canterbury Swarm In past centuries, and even in this century, objects from outer space may have collided with the Earth and moon. Now at least one astronomer suggests that three previous collisions may be related -- and that an actual swarm of objects may occasionally pass through the Earth/moon system. On June 25 in the year 1178, Gervase of Canterbury reported seeing "a flame" shoot up from the moon. Later a young lunar crater was identified in the same region -- a possible result of the impact. More recently, an object from outer space may have collided with Earth in Siberia. That was the famous Tunguska event of June 30, 1908. A third possibly connected event took place in 1975 -- when a storm of meteoroids struck the moon -- and was recorded by a network of seismometers left by Apollo astronauts. In this case, as in the first two, the date was around the end of June. Ken Brecher, an astronomer from Boston University and NASA's Goddard Space Flight Center, noticed that these three events all occurred at the same time of year -- even the same time of day. He suggests that the breakup of a large comet sometime in the past several thousand years may have created what he calls the Canterbury Swarm -- a possible swarm of space objects that occasionally strike the Earth and moon. The next encounter with this hypothetical Canterbury Swarm would not be until the year 2042 -- but, if it exists, the swarm might be glimpsed passing within 20 million miles of Earth during 1985. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin