Deep space telescopes

The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo’s telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics throughout the complete electromagnetic spectrum. Such information is there for the taking, from millimiter wavelengths to gamma rays. Forty years astronomy from space, covering now most of the e.m. spectrum, have thus given us a better understanding of our physical Universe then the previous four centuries of classical astronomy. For example, the “global sky” e.m. spectrum has been shown to contain the pictorial history of our Universe. It goes from the original big-bang imprint, the microwave background, to the IR bump, signalling the formation of the first stars, to the X-ray peak, tracing the formation of black holes, to the gamma-ray continuum of non-thermal, particle accelerator processes. For such an understanding, specialized telescopes have had to be imagined, built and flown in space, which have challenged the ingenuity of physicists and engineers. A new generation is now being conceived, pushing astronomy to capture at all wavelengths as many celestial photons as possible and to extract, with the best possible accuracy, the information they carry: their point of origin, their energy, their polarization and their arrival times. Our Universe, however, also sends us information, still largely untapped, outside the e.m. spectrum. In parallel to groung-based experiments, we are now learning to exploit from space other channels, from gravitational waves to cosmic rays and more, including verifications (impossible on our Earth) of fundamental physical laws and in situ exploration of solar system objects. Especially with space astronomy, we may also be on the brink of discovering “new physics”, which might be necessary since, for example, we now know that our beloved baryons make up only a tiny fraction of our Universe. Like Simplicio would have, we call “dark matter” and “dark energy” all that is beyond our current understanding of physics, but clever design and use of telescopes in pace might allow us to probe into such “darkness".