Astronomy awaits
the next challenge: to study the dawn of the
universe
New National Academy of Sciences report calls for bold steps in next decade
By Diane
Ainsworth, Public Affairs
Posted July 12, 2000
In the first decade of the new millennium, humanity is poised to take a giant step forward in understanding the universe and its place in that vast arena.
"This is a terrific time for science," said Berkeley astrophysicist and newly named chairman of the Physics Department Christopher McKee, who has co-authored a new National Academy of Sciences report detailing the next set of national priorities in astronomy and astrophysics research.
"We are really ready to understand how the universe evolved from the big bang to the formation of our own planet earth," he said. "To achieve that goal, we must use the universe as a laboratory -- a unique laboratory -- for probing the laws of physics under conditions that are not accessible on earth."
The new survey, titled "Astronomy and Astrophysics in the New Millennium," was co-chaired by astrophysicist Joseph Taylor, who is dean of the faculty at Princeton University. A prepublication draft of the report is available at http://national-academies.org/bpa/reports online.
"We must survey the universe and its constituents, including galaxies as they evolve through cosmic time, stars and planets as they form out of collapsing interstellar clouds in the galaxy, and interstellar and intergalactic gas as it accumulates the elements created in stars and supernovae," McKee and Taylor reported in the survey, prepared by a special advisory committee representing astrophysicists and astronomers from institutions across the country.
"Other investigations that hold great promise in the next decade arise from very recent discoveries," they noted. "These discoveries point to the mysterious dark matter and, perhaps, dark energy that so strongly influence the large-scale structure and dynamics of the universe."
Two years in the works, the Astronomy and Astrophysics Survey Committee was charged with surveying both ground- and space-based astronomy programs and recommending priorities for new initiatives in the decade 2000 to 2010. In addition, the committee was asked to evaluate the effective implementation of both the proposed initiatives and existing programs. Initiatives calling for direct sampling of the earth and planets, either by robotic spacecraft or human exploration, were not covered since they were addressed in other reports by the National Research Council.
To meet its mandate, the committee formed nine panels composed of more than 100 distinguished members of the astronomical community to address the scientific goals of the various branches of astronomy. A wide range of viewpoints was solicited from the panels, from representatives of the international astronomical community, and through forums held by the American Astronomical Society.
Several key questions that are ripe for advances in the coming decade were identified:
• Determining the large-scale properties of the universe: the amount and distribution of its matter and energy, its age and the history of its expansion.
• Studying the dawn of the modern universe, when the first stars and galaxies formed.
• Understanding the formation and evolution of black holes of all sizes.
• Studying the formation of stars and their planetary systems, and the birth and evolution of giant and terrestrial planets.
• Understanding how the astronomical environment affects earth.
Although these scientific themes hold the greatest promise for progress now, they are merely one piece of a much larger tapestry that is the burgeoning field of astronomy and astrophysics.
"We cannot hope to understand the formation of black holes without understanding the late stages of stellar evolution," McKee and Taylor reported in the new survey. "The full significance of observations of the galaxies in the very early universe will not be clear until we understand how these galaxies have evolved over time."
In setting priorities for new initiatives, the report stressed the importance of completing the projects recommended in the last survey. Funding for the operation of facilities and their associated data analysis was also recommended. Unrestricted grants to support research that advances the frontiers of astronomy were identified as essential to that effort as well.
Major initiatives were prioritized according to their importance in answering the key questions of the next decade.
"The project rated highest on the priority list by the committee was the Next Generation Space Telescope, which is the successor to the Hubble Space Telescope and part of NASA's Origins Program," McKee said. "The orbiting observatory will be a 26-foot telescope with 100 times the sensitivity and 10 times the image sharpness of Hubble in the infrared. That capability will revolutionize our understanding of how galaxies formed long ago and how stars and planets form in the Milky Way galaxy today."
The Giant Segmented Mirror Telescope was selected as the top ground-based project and the committee's second priority overall. This giant segmented telescope would have a diameter of nearly 100 feet and would complement the next generation telescope in tracing the evolution of galaxies and the formation of stars and planets.
Constellation-X Observatory, an array of orbiting x-ray telescopes for studying the formation and evolution of black holes and for tracing the evolution of the elements, took third place. Among the other major initiatives recommended by the committee is the Terrestrial Planet Finder, an ambitious NASA mission that would search for earth-sized planets around nearby stars and seek evidence for life.
The committee also recommended a number of moderate projects. The highest priority among them is a program to build instruments at private observatories in exchange for observing time to the rest of the astronomical community.
The second priority among the moderate missions is the Gamma-ray Large Area Space Telescope, a joint NASA-Department of Energy mission to observe incoming gamma rays &endash; the most energetic form of electromagnetic radiation &endash; in order to study the powerful jets emitted by supermassive black holes in quasars.
Next on the list is the Laser Interferometer Space Antenna, which will be able to detect gravity waves from supermassive black holes that are thought to be merging throughout the visible universe, as well as the gravity waves emanating from close binary stars. The European Space Agency has expressed its interest in a collaborative mission, the survey noted.
Also among the moderately-priced projects is the Combined Array for Research in Millimeter-wave Astronomy, which will combine the radio telescopes at the Hat Creek Radio Observatory, operated by Berkeley, with the radio telescopes at Owens Valley, operated by the California Institute of Technology.
The committee recommended several small initiatives as well. The top priority among these is the National Virtual Observatory, which will give both professional astronomers and the public access to the large data archives astronomers are creating, McKee and Taylor said.
"Astronomers can play a crucial role in contributing to science education in the U.S.," the authors noted. "Astronomical ideas have a universal appeal, enabling astronomers to make a disproportionate contribution to the improvement of public science literacy, despite the relatively small size of the astronomical community."
July 12 - August 16,
2000 (Volume 29, Number 1)
Copyright 2000, The Regents of the University of
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