The last three years have been marked by changes, highlights and progress. Organizationally, commission 7 has joined Division I and plans proceed for commissions 8 and 24 to merge in 2000. They have had a common vice president during this triennium. Sadly, the Royal Greenwich Observatory was closed after over 200 years, but Her Majesty’s Nautical Almanac Office has continued at Rutherford Appleton Laboratory. In St Petersburg, Russia, the Institute of Theoretical Astronomy was abolished, with some of the personnel relocated to the Institute of Applied Astronomy and Pulkova Observatory. In Paris, France, the Bureau des Longitudes was reorganized as the Institute of Celestial Mechanics-Bureau des Longitudes as part of the Paris Observatory.

Developing countries have many claims on their limited resources and astronomy can expect only a small share of a small “pie”. A useful rule of thumb is that a country’s expenditure on astronomy is likely to be of the same order of magnitude as its per capita Gross National Product multiplied by the number of professional astronomers in the country. In the light of this, we consider how governments of developing countries can help their astronomers, how we can help them and how they can help themselves.

The Commission has established its own website (http://ssd.jpl.nasa.gov/iau-comm4/) containing the following main topics:

The Commission presently has 88 full members and 3 consultants.

Research in Celestial Mechanics, for the past three years, has mainly focused on the understanding of Chaos on all its aspects. The always larger number of potential applications (meteors, KBO, NEA, asteroids of the main belt but also exoplanets or galactic motions) and the development of new efficient tools, like the symplectic integrators, have allowed the passage from QUALITATIVE models (for example the transfer mechanisms) to real QUANTITATIVE results (like the calculation of lifetimes). This important step has contributed to (re)create collaborations between theoreticians and observers (for example, in the prediction of catastrophic impacts) and to situate the Celestial Mechanics in a wider scientific context.

I discuss the critical conditions for undertaking a successful research program in a developing country. There are many important factors, all or most of which have to be satisfied: funding, library holdings, computing access, Internet access (e-mail, WWW, ftp, telnet), collaboration with astronomers in developed countries, provision of proper offices for staff, supply of graduate students, access to travel for conferences, ability to publish in international journals, critical mass of researchers, access to a telescope (for observational astronomers), support from and interaction with national electronics, optics and precision engineering industries, a scientific culture backed by a national scientific academy, and lack of inter-institutional rivalry. I make a list of a total of 15 key factors and rank them in order of importance, and discuss the use of an astronomical research index (ARI) suitable for measuring the research potential of a given country or institution.

I also discuss whether astronomers in developing countries in principle fare better in a university or in the environment of a government national observatory or research institution, and topics such as the effect of the cost of page charges and journal subscriptions on developing countries. Finally I present some statistics on astronomy in developing countries and relate the numbers of astronomers to the size of the economy and population in each country.

Astronomy can help, directly or indirectly, in the acquisition and creation of new technologies, in attracting young people to scientific careers, in providing a scientific education to the general public and in fostering international collaborations. These and other benefits of professional astronomy are critically reviewed in the context of countries which are facing urgent, basic needs. Several criteria are suggested for the best implementation of astronomy in developing countries and the most efficient collaboration with industrialized countries.

The present triennial commission report embraces mainly activities in wide angle, optical astrometry. With the successful development and application of new techniques from Earth (e.g. optical interferometry, CCD’s) and space (Hipparcos mission and new projects) the sub-division between Commissions 8 (Positional Astrometry) and 24 (Photographic Astrometry) has become questionable. During the GA at Kyoto in 1997 all steps for a merger of both commissions have been taken. The final merging will take place at the forthcoming GA in Manchester. For a more complete overview on astrometrical work done in the past triennium the reader should also take notice of the report of Commission 24.

There are many interlocking factors determining the introduction of astronomy education in Zambia. The process of infusing this new subject into an education system so centralised as that of Zambia is extremely complex. At school level the process is more complex than at university level, as all syllabuses are developed by a central body, Curriculum Development Centre (CDC) whose priorities are determined by perceived social and economic needs of the country. The prevailing notion in Zambia is that astronomy has no direct bearing on future employment needs. It is therefore not surprising that astronomy is at the bottom of the priority list among school subjects. The recent upsurge of interest in astronomy at the University of Zambia opens up the necessary background for developing astronomy in both school and university curricula. The University has recently formed the Astronomical Society and the Working Group on Space Science in Zambia. Coupled to this are exchange visits and collaborative work between the Physics Department of the University of Zambia and the South-African Astronomical Observatory. In this paper we present a review of the current activities in space science in Zambia and how they relate to the development of astronomy education.

The triennial report of Commission 19 was composed from the contributions of its members. Space does not permit a listing of their names, but their contributions are sincerely appreciated. Unfortunately because of limited space it is also not possible to provide in this report the extensive list of publication of the Commission members. The list of publications is however available on the Commission 19 web site at maia.usno.navy.mil/iauc19.

The scope of scientific interests of about 130 Commission members is much more complex than one may expect from the title of the commission. Besides traditional topics like the compilation of astrometric catalogues and the construction of an inertial reference system, more and more investigations performed by our members have been dedicated to the astrophysical interpretation of observations including among others astrometric data.

Vietnam was scientifically completely isolated for almost 30 years. With French help, several lecture courses have introduced modern astrophysics to Vietnamese physicists, and four students are studying abroad. The IAU program “Teaching for Astronomy Development” (TAD) has concentrated on modernizing the on-going astronomy course for students in the third year of the pedagogical universities. Three one-to-two week “Teachers’ Workshops” have served to introduce selected up-to-date astronomical topics and a few modern teaching methods. The TAD program has also provided appropriate journals, books, a PC and educational software. A new text, Astrophysics, in Vietnamese and English on facing pages and with color pictures – apparently a first for any textbook in Vietnam – will first be used starting in September 2000.

Future additional activities: collaboration to plan a new astronomy course in the twelfth grade of the natural science branch of the secondary schools; collaboration so that the 41-cm telescope and astronomers in Hanoi can produce some simple quality science; helping the only planetarium in Vietnam to acquire a wider range of offerings; helping to create a set of B.Sc.-level astrophysics courses for three universities; and supporting the Vietnamese Astronomical Society in effective public outreach.