224 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1954 



such a situation anything might happen — for example, a collision 

 between them would ultimately result, given enough tune. Since the 

 solar system had its beginning some 4,000 million years ago, and since 

 tests on meteorites and tektites, through a study of their helium and 

 argon contents, generally indicate an age for them of less than 100 

 million years (Martin, 1953; Paneth, 1952; Suess, Hans E., 1952), it 

 appears that at least 3,900 million years were required to produce such 

 a collision. During this time the planets would have made hundreds 

 of millions of revolutions about the sun and thus would have had an 

 opportunity to suffer great orbital changes if only slightly perturbed 

 each time the vicinity of Jupiter was approached. 



100 



1000 



2000 3000 



WAVELENGTH, MILLIMICRONS 



4000 



5000 



Figure 4. — Spectral infrared transmittances of five tektites from various sources: No. 8, a 

 moldavite; No. 6, a Georgia tektite; Nos. 5a and 5b, Texas bediasites; No. 1, a Philippine 

 rizalite. 



Or take another possibility, for example. Suppose there was only 

 one planet within this region of the solar system. Again perturba- 

 tions by Jupiter would constantly change the planet's path through 

 changes in the eccentricity or inclination of its orbit in a manner sim- 

 ilar to that in the example for the two planets. Since Jupiter has 

 numerous moons (no doubt originally there were many more than at 



