On July 4, 2005 the probe Deep Impact blasted a crater in Tempel 1, one of these celestial travelers
... Scientists want to observe inside the stadium-sized crater formed by the ... 
Each of them is not as good as Tempel 1 in one way or another,... [DOC] [TLE] NASA Deliberately Crashing Satellites (3 pages) [PAR] New Tactics for Space Scientists ... One thing I see a lot in NASA reports is the 
results are unexpected.