The Inaugural Ceremony was held at the Convention Center, Baltimore, in the presence of distinguished representatives from the Government of the United States, the State of Maryland, the City of Baltimore, the Johns Hopkins University, the National Aeronautics & Space Administration, the and the US National Committee for the IAU.

The chair was taken by Dr. A. Davidsen, co-Chairman of the Local Organizing Committee, from the Johns Hopkins University.

A rousing aubade, specially composed for the occasion by Elam Ray Sprenkle, was beautifully performed by the Annapolis Brass Quintet under the direction of David Cren.

An Extraordinary General Assembly was held immediately preceding the first session of the General Assembly on 1988 August 2 to amend the Statutes of the Union to permit the election of a President-Elect to the Executive Committee and to institute a new category of adherence to the Union-Associate National Member status for countries in the process of developing astronomical activity.

Je voudrais commencer cette première séance de la Vingtième Assemblée Généale de l’Union Astronomique Internationale en vous souhaitant d’une part la bienvenue et, d’autre part, un séour non seulement très agréable mais surtout très profitable au point de vue scientifique.

It was the President’s sad duty to report the deaths of two former past Presidents of the Commission, W. Fricke who had also been a Vice-President of the IAU and a President of Commission 8, and D. H. Sadler who had been Superintendent of H.M. Nautical Almanac Office from 1936 to 1969 and was once General Secretary of the IAU.

Given here are reports on the scientific and business meetings held in Baltimore involving Commission 9 only. Reports on the following Joint Commission Meetings co-sponsored by Commission 9 (JCM 3 and JCM 6), and on three additional meetings organised jointly with other Commissions, will be found elsewhere in this Volume or in Highlights of Astronomy (Volume 8):

1. - High Angular Resolution Imaging from the Ground (JCM 3)

2. - Stellar Photometry with Array Detectors (JCM 6)

3. - Problems of IR Extinction and Standardization (with Commission 25)

4. - Future Space Programs (with Commission 44)

5. - Gamma-ray, X-ray, Extreme and Far UV, IR and Radio Astronomy from Space (with Commissions 40 and 44)

A brief review was given of the substance of the discussion of the previous business meeting of Nov. 21 1985 on the subject matter of the commission. There was general endorsement of the view of that meeting that the purpose of the Commission was to keep a watching brief on the energy exchange processes of atomic and molecular physics, and of related spectral and structure data of atomic and molecular species. Such information is essential to the use of astronomical observations for astrophysical diagnosis and modelling.

In astrophysics, as in all research fields in which molecular spectra play important roles, there has been a continuing need for compendia of information on individual band systems. Firstly there is a requirement by observers and experimenters for aids to definitive identification of observed spectral features. Secondly there are needs by observers, by those who make diagnostic interpretations of spectral profiles, and also by theorists, for definitive critical compilations of appropriate molecular data with reference to the relevant literature. The continued popularity of various editions to Pearse and Gaydon’s Identification of Molecular Spectra (1) and to Huber and Herzberg’s Constants of Diatomic Molecules (2) are clear evidence of this.

Tribute is paid to those members of Commission 15 who have passed away since the last General Assembly: Dr. Ludwig BIERMANN, Dr. Nicholas BOBROVNIKOFF, Dr. Richard Heinrich GIESE, Dr. Marie-Therese MARTEL, Dr. Reginald WATERFIELD.

The Commission had one Business Session, two Science Sessions on “News in Cometary Research” (organized by C. Arpigny), one Science Session on “News in Minor Planet Research” (organized by A.W. Harris), a Joint Discussion with Commission 20 on “Major Observing Programs and Data Bases” (organized by Y. Kozai and L. Kresak), and a Joint Discussion with Commission 22 on “Interrelation of Meteor Streams, Comets and Asteroids” (organized by P. Babadzhanov and L. Kresak)