Executive Summary

The current era is perhaps the most exciting time in the history of astronomical research. The reasons for this are many. The depth of knowledge that astronomers now possess is deep and profound. Within less than a decade we should know the fundamental parameters of the Universe (its expansion rate, the mass density, whether there is a cosmological constant) to better than 5% and finally be in a position to state whether the Universe is open (will expand forever), closed (collapse back on itself) or critical (decelerate to zero expansion velocity after an infinite amount of time). We have some ideas (although not a complete theoretical picture) of how stars and galaxies formed and evolved. We have discovered planetary systems outside our own solar system. The resources available to attack these and other problems is prodigious. Within about 5 years there will be a suite of 15 6m+ telescopes on the ground. Both ESA and NASA have developed very ambitious space programs that will place observatories above the Earth to explore the electromagnetic spectrum from 1#1-rays to microwaves radiated by extraterrestrial sources. A number of telescopes are planned that will be devoted to locating and imaging terrestrial planets orbiting around nearby stars. The instrumentation that is and will be available to use with both the space and ground-based telescopes is innovative and in many cases is limited by physics not engineering. New technology is being applied to astronomical instrumentation and telescopes in a manner never seen before (e.g. adaptive optics, lightweight materials). Astronomy is becoming an increasingly interdiscplinary subject with close links to such subjects as computing technologies (e.g. neural networks, terapix initiative), biology (astrobiology has become a discipline that can be studied at some universities) and chemistry (the interstellar medium). Public interest is almost insatiable for news of the most recent astronomical discovery. It is almost a daily occurence that some story related to astronomy appears on the front page of major newspapers. NASA and ESA are both expending a major effort on public outreach and introductory astronomy courses are amongst the most popular at universities. The important lesson here is that astronomy is in the process of enormous change and CFHT must now react to this change and position itself to remain at the forefront of astronomical research as it has been for the past 20 years.

What science will be the most compelling for a new or refurbished CFHT to attack? Our consensus is that there are 5 questions that will provide the strongest intellectual challenge for astronomy over the next few decades and for which real progress can be made given the right mix of instrumentation.

1.

Are we alone in the Universe?

2.

What is the Universe made of and what is its overall geometry?

3.

How did our and other solar systems form and evolve?

4.

What were the first sources of light in the Universe and how did galaxies like our own come into being?

5.

Are there things in the Universe that we haven't as yet dreamed of?

All of these themes are linked by the common thread of darkness.

1.

Any Earth-like planets capable of supporting life on them will shine solely by reflected star light in the optical/IR and hence be very faint. They will also be in close proximity to a very much brighter sun-like star and thus be most difficult to observe.

2.

It is known that most of the matter in the Universe is non-luminous and this ``dark matter'', comprising between 90 and 99% of all the mass in the Universe, does not appear to be emitting radiation at any wavelength that has thus far been explored.

3.

The formation of stars and planetary systems takes place in dusty regions from which little optical or ultraviolet radiation escapes.

4.

Before the galaxies and the massive stars in them formed the Universe was largely dark.

5.

Any as yet undiscovered phenomena in the Universe will occupy a part of observable parameter space that is far to one side of the regions that have thus far been explored with ground- and spaced-based instruments. For this reason, as seen from the Earth, such objects will likely be extremely dim at whatever wavelength they may radiate.

What the NGC committee has developed is a ground-based strategy for an optical instrument that can illuminate many of these currently dark issues concerning the Universe in which we live. Along the path to achieving these goals there will be the opportunity for numerous side-trips to other interesting and more detailed astronomical projects.

To achieve the scientific goals that we have recognized, the committee suggests the following replacement/refurbishment program for the CFHT.

(1) The existing CFHT should be operated with most of its current suite of instruments (except for the possible addition of a wide field IR-imager) for about another decade. With MEGACAM, OASIS, the Adaptive Optics Bonnette, a high resolution spectrograph and the wide field IR-imager CFHT will continue to be competitive in many areas of research (galaxy surveys, weak lensing, stellar population studies, detailed observations of active galactic nuclei, stellar spectroscopy).

(2) Beginning almost immediately the CFHT Board should initiate a ``Phase A'' study of a large optical telescope, in the range of 25m+. This instrument, optimized for imaging and spectroscopy, could be built on the current CFHT site. This site, by all accounts, remains the premier locale on Mauna Kea and the community will want to maintain its use of it. This telescope will be able to accomplish the prime scientific goals outlined above and in addition, at 25m+ it will have the minimum size capable of exploiting new discoveries made by the Next Generation Space Telescope (NGST) currently scheduled for launch by NASA in 2007.

(3) If it is decided to build this large telescope, construction could begin in about 2008 at which time the current CFHT operations would cease.

(4) If, at the completion of the ``Phase A'' study in 2002 - 2003 or if, for other reasons, the decision is made not to go forward with the large telescope, then a more modest building plan for a future CFHT should be developed. Such refurbishment might conceivably involve constructing a modern 8m instrument optimized for wide field imaging and high resolution spectroscopy. Another, even more modest option, would be to simply refurbish the existing telescope. This would definitely have the effect of reducing the profile of CFHT from a world-class observatory to one which operates mainly in a support role for larger telescopes.