The Chandra X-Ray Observatory opens the book on the high-energy universe.
- By James S. Schultz
- Air & Space magazine, March 2002
NASA/SAO/G. Fabbiano et al.
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In the end, Chandra's deep view of the universe is no arcane scientific exercise but an exploration that brings a practical understanding home to Earthly doorsteps. Since its formation, the planet has been bombarded by extraterrestrial material. Among the arrivals have been the very elements today found in the crust and mantle, including those we rely on every day. According to Jeffrey Linsky, an astrophysicist at the University of Colorado who has used the telescope, "Your computer wouldn't work without supernovas. There's where the silicon comes from," he says. "The iron in our blood is from supernova." Indeed, humankind owes its very existence to stellar eruptions that give off material that drifts through the void, enriching the stellar medium and seeding planets, perhaps even life itself.
A Luminous Mind
Celebrated scientists, Greek and Roman gods, noted explorers: Names of the illustrious and esteemed have long been given to spacecraft on missions of exploration. "NASA's challenge to [the Chandra team] was to find a name that would also speak to people's imaginations," says Chandra X-ray Center director Harvey Tananbaum. "So we sponsored an essay contest."
The 1998 contest to rename the Advanced X-ray Astrophysics Facility, or AXAF, drew 6,000 entries, with suggestions ranging from "Isaac Asimov" to "Marie Curie," the Polish-born French physicist who coined the word "radioactivity" in 1898. One name seemed a favorite of many entrants: that of astrophysicist Subrahmanyan Chandrasekhar. The six-member selection committee agreed, and the orbiting telescope's official moniker became the Chandra X-ray Observatory.
Born in Lahore, India, on October 19, 1910, Subrahmanyan Chandrasekhar would eventually be called Chandra by friends and colleagues, a Sanskrit word meaning "moon" or "luminous." Studying first in India and then in England, Chandrasekhar was trained as a physicist before emigrating to the United States in 1937, where he taught at the University of Chicago for the remainder of his life. There he proved a popular teacher—shepherding 50 students to Ph.D.'s during his career—and prolific author, writing 10 books on a variety of topics, including the relationship between art and science.
Among his most notable works was the discovery of what is now known as the Chandrasekhar limit, which defines the physical limits on the mass of a white dwarf star. Earth's sun appears destined to become a white dwarf once its nuclear energy is entirely spent billions of years from now. By contrast, stars more massive either explode into novas or supernovas, leaving behind neutron stars, or collapse to form black holes.
In 1983, Chandrasekhar won the Nobel Prize for his studies of the physical processes important to the structure and evolution of stars. For 19 years, Chandrasekhar also served as editor of the Astrophysical Journal. He continued to write and teach at the University of Chicago until his death on August 21, 1995.