When Science Drives

Matt Mountain, mmountain@stsci.edu

As 2011 drew to a close, a suite of special events marked it as a phenomenal year for observational astrophysics. In October, in Chile, the Atacama Large Millimeter/submillimeter Array (ALMA) achieved first light. On December 7, the 10,000th refereed paper based on Hubble observations was announced. The same day, the 20th annual call for Hubble proposals was announced. Three days later, in Stockholm, Saul Perlmutter, Brian Schmidt, and Adam Riess were awarded the Nobel Prize in Physics for discovering the accelerating universe.

And on November 18, 2011, with full bipartisan support and thanks to the efforts of a large portion of the astronomical community as well as 33 Nobel Laureates, President Obama signed into law the bill that increased NASA’s science budget and fully funded the James Webb Space Telescope so that astronomers in the U.S. and elsewhere will be able to follow up on Hubble’s extraordinary success.

These events illustrate that when science is allowed to drive and the community works constructively together, remarkable outcomes are possible.

In awarding the Nobel Prize, the Swedish Academy of Sciences cited the powerful partnership between ground- and space-based telescopes in the research. The initial discovery of cosmic acceleration was made using National Optical Astronomy Observatory facilities. Later, Hubble provided extraordinary evidence that the acceleration was real. In both cases, the observing time was awarded by peer review based solely on scientific merit.

By the deadline for Cycle 20 on February 24, 2012, the Institute had received 1,090 General Observer (GO) proposals, oversubscribing the available observing time by 6:1. The proposals are highly diverse, ranging across the gamut of astrophysics and planetary science. In their proposals and published papers, astronomers demonstrate that Hubble—already well established as the most productive telescope ever—is still in huge demand.

It’s important we recognize that Hubble’s achievements are ultimately due to the efficiency and effectiveness of peer review. Once a year, for the last twenty-two years, over a hundred astronomers from the U.S. and around the globe have come to Baltimore to recommend the best programs of all the proposals received. They huddle in conference rooms for days, read hundreds of proposals, and formulate recommendations with scientific merit as the overarching criterion. Though they come from a wide range of disciplines, science is their working language.

The selected proposals in any Hubble Cycle are diverse in scale as well as topic. At one end of the spectrum are many smaller programs with individual PIs, and at the other are usually a few really large teams winning large Treasury or Multi-cycle allocations (see Figure 2). This diversity of both size and science is a hallmark of NASA’s Great Observatories—Hubble, Chandra, and Spitzer.

Another hallmark of NASA’s Great Observatory model is the grant support made available for the selected research programs. The Institute has so far dispersed over $300M in GO funding for Hubble. Much of this funding supports young astronomers—graduate students and postdocs—who are the PIs of tomorrow.

The fact that the Hubble science engine exists today at all, of course, is due to the compelling science case and solid community support that materialized in the 1970s and has remained rock-solid for four decades. Superb science and community consensus are also at the root of the successes of Chandra, Spitzer, and most recently ALMA—the most complex and powerful sub-millimeter telescope array ever built. Its development culminates a decade of international cooperation and broad consensus on its scientific merits among astronomers worldwide.

Almost by definition, implementing bold new science programs means investments to develop enabling technology. Such investments are cumulative and progressive, as illustrated by the science-driven advance of technologies for ever-larger primary mirrors to collect more light. Two examples are provided by Webb and the new generation of very large telescopes on the ground.