Observations are the lifeblood of astronomy: Our knowledge of the Universe is totally dependent on access to the electromagnetic spectrum. Long confined to visible light, astronomical discoveries now increasingly result from observations made in other wavebands, from neutrinos and gamma-rays to infrared and radio wavelengths. Some of these observations must be made from spacecraft outside the Earth's atmosphere, and key scientific breakthroughs in the last four decades have been made from space. Other observations can be made from the ground, but are vulnerable to noise generated in space. This is particularly true at centimetre and millimetre radio wavelengths, where new discoveries due to tremendously increased receiver sensitivity are severely compromised by sideband noise from communications satellites. To illustrate the weakness of astronomical sources, an ordinary portable telephone, if placed on the Moon, would be the third strongest radio source in the sky at its wavelength! The IAU, in a collaboration with URSI and COSPAR spearheaded by the Inter-Union Committee IUCAF, is making vigorous efforts to preserve the most important frequency bands for science in the face of overwhelming commercial pressure for ever more ambitious satellite communications systems. Some understanding for the issue appears to be forthcoming as also non-scientific issues such as airline safety are beginning to suffer, but the constant efforts of all concerned in this uphill battle will be required in the foreseeable future.

The ever-worsening degradation of the terrestrial environment is a global problem. Its effects on astronomy are described under the common title Adverse Environmental Impact. "Ordinary" ground-based light pollution is, in fact, best observed from space where its global extent and constant growth is clearly visible. Ironically, in a world with limited energy resources, the radiation of so much light into space not only renders much of the Earth's surface unusable for deep-sky astronomy, but also represent the useless output of a large number of power plants and the waste of much fossil or nuclear fuel. Simple and well-established improvements in lighting techniques exist which will benefit national economies as well as astronomy, and they should be promoted worldwide.

Light pollution can, however, also come from space, in the form of illuminated spacecraft or space debris. All astronomers can report on observations with large, expensive telescopes that have been ruined by satellite trails (my own latest example being from New Year's Eve 1997/1998), and the problem shows an increasing trend. In fact, increase is all it can, since objects in high orbit will not disappear in a few centuries if launches were stopped right now (unlike the greenhouse effect, we hope). However, in addition to the satellites launched for specific purposes under government control, there is unrelenting pressure from commercial interests for bright objects to be launched for mere advertising purposes. The night sky is one of the few natural resources still left to the population of the entire world, only apparently more easily accessible and less vulnerable than the Antarctic continent, which is covered by very detailed and extensive international conventions. It is becoming urgent to protect the sky by international agreements along the models set for the Antarctic continent or submarine archaeological treasures. It would be ironic if, just as mankind is beginning to detect sister planets around other stars, we were to blind our eyes and deafen our radio ears so as to become unable to detect any signals from them!

Within the modest means available to a non-governmental organisation, the IAU has for many years conducted generally successful educational programmes in developing countries, including the International Schools for Young Astronomers, Visiting Lecturer Programmes, and Teaching for Astronomy Development initiatives, and is providing travel support for exchange programmes and scientific meetings. In recent years, an increasing fraction of these activities has been coordinated with the very successful series of UN/ESA Workshops in Basic Space Sciences; and the IAU and COSPAR is collaborating to develop a concept of joint workshops and similar courses within the ICSU organisations, also to be coordinated with the new major ICSU Programme on Capacity Building in Science.

The IAU realises that the subject of Space Science - and the interest of Member States in supporting it - encompasses a much wider range of activities than astronomical research from space. And while the informal nature of the IAU - and the totally peaceful and non-commercial nature of astronomy - often permit us to undertake pilot projects at a very early stage in a political development, the IAU clearly cannot command the kind of official resources and long-term commitment available to inter-governmental organizations such as those achieved by, e.g. the UN-OOSA/ESA initiatives. However, the immediate appeal of astronomy to large numbers of young people is a strong incentive for them to embark on studies and eventually a career in science, and many of the physical and computational skills acquired by astronomy students are immediately transferable to other fields. Within the field of science education for the future, the IAU thus sees itself as one instrument in the orchestra, backed by the collective experience of professional scientists and educators in astronomy worldwide; it looks forward to a harmonious cooperation with the other players.