70 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1957 



Dr. John H. Waddell has been investigating, theoretically and ob- 

 servationally, the velocity fluctuations in the solar photosphere and 

 their effect on the line spectrum of the solar disc. 



Dr. Alan S. Meltzer, who joined the staff in October 1956, has been 

 conducting two studies of solar line profiles : I, variation of Doppler 

 half-width with atomic weight ; II, parity effect. During the months 

 of March and April 1957, he made observations relevant to these two 

 studies at the Sacramento Peak Observatory, Sunspot, N. Mex. 



Dr. William M. Sinton, who joined the staff in July 1956, left in 

 May 1957 for the Lowell Observatory at Flagstaff, Ariz. While with 

 the Smithsonian he used photoconductive equipment and the Wyeth 

 61-inch reflecting telescope of the Harvard College Observatory to 

 observe the intensity of radiation from the planet Mars in the vicinity 

 of 3.46 microns, during the planet's 1956 opposition. The reflection 

 spectra of most planets show absorption in this spectral region arising 

 from the carbon-hydrogen bond. The absorption bands are so dis- 

 tinctive that if present in Mars light they would be evidence for or- 

 ganic molecules and, therefore, of life on Mars. The electrical meas- 

 urements with the 61-inch telescope indicated the probable presence of 

 the distinctive bands and thus of life, probably vegetable, on Mars. 

 The effect of solar radiation on Mars is obviously important in under- 

 standing its effects on the earth. 



Meteoritical studies. — Meteoritical studies have been a part of the 

 Smithsonian Institution's scientific research program for over 80 

 years, during which time its meteorite collection has been developed 

 into one of the most outstanding in the world. The only tangible 

 extraterrestrial material, meteorites are of great astrophysical interest. 

 Under Dr. John S. Einehart's direction, the Astrophysical Observatory 

 undertook, during 1956, a freshly oriented program of meteoritical 

 research, with the principal objective of resolving astrophysical prob- 

 lems. This program is now well under way with the pursuit of the fol- 

 lowing specific activities : A study of the processes that cause the abla- 

 tion of meteorites during their flight through the atmosphere; the 

 design and construction of an electron fluorescent X-ray micronana- 

 lyzer to be used especially for studying the distribution of nickel, 

 iron, and cobalt within meteorites ; the collection and identification of 

 airborne extraterrestrial material ; the sending of an expedition to the 

 Arizona Meteorite Crater for determining the distribution of meteor- 

 itic debris about the crater; and the determination of the ages of 

 meteorites by radiochemical techniques. All these efforts have been 

 directed toward solving the riddles of the ages — the origins and 

 natures of extraterrestrial material. 



The study of ablation of meteorites has been concerned with the 

 distinct shapes and surface features of a large number of meteorites, 



