Human knowledge of the cosmos increased dramatically in the 20th century as large ground-based telescopes and orbiting observatories such as Hubble allowed us to see far beyond our galaxy. In the current century, investigations of dark energy, dark matter and other astronomical mysteries promise even greater understanding.
Smithsonian astrophysicist Harvey Tananbaum, a pioneer in X-ray astronomy, is the director of the Chandra X-Ray Center at the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts. Over the past 30 years, NASA funding has enabled SAO to build a high-resolution camera, play a leading role in overseeing the design and construction of the unique Chandra X-ray telescope and control Chandra’s science and flight operations following its launch in 1999. With its unrivaled ability to produce high-resolution X-ray images, Chandra has allowed scientists all over the world to observe a fantastic range of phenom-ena. It has also provided the most direct evidence to date that most of the universe’s matter is “dark,” its presence detected only indirectly by observing its gravitational pull on normal matter.
“Chandra has helped track how dark energy has slowed the growth of galaxy clusters and offered us clues about what the universe’s ultimate destiny might be,” Tananbaum says. Chandra can follow matter heated to temperatures of millions of degrees as it swirls toward the black holes that lurk in most galaxies. Near the black hole, an instability can trigger winds of hot gas and jets of energetic particles. These outflows then limit the further growth of large, massive galaxies. Chandra has also revealed amazing details about the dynamics of shock waves generated by exploding stars. Its many accomplishments are explained in detail on its award-winning Web site (www.chandra.harvard.edu).
SAO has participated in other NASA-funded astronomy programs, such as developing an infrared camera on the Spitzer Space Telescope and an extreme ultraviolet imager on the recently launched Solar Dynamics Observatory. In addition, SAO researchers are contributing to NASA’s Kepler Mission, a space telescope that has discovered five new planets orbiting five different stars outside our solar system. If life is eventually found on planets like these, Kepler will have played a key role in the discovery. In the 21st century, with our superb facilities, innovative researchers and strong partners, the Smithsonian will continue to develop next-generation technologies and lead missions to uncover the secrets of the cosmos.
G. Wayne Clough is Secretary of the Smithsonian Institution.