Spacecraft to bring back comet dust
Comets have long lit up the sky and the imaginations of scientists. Now these icy bodies, from the beginnings of the solar system, are finally ready for their close-up.india Updated: Jan 10, 2006 14:04 IST
Comets have long lit up the sky and the imaginations of scientists. Now these icy bodies, from the beginnings of the solar system, are finally ready for their close-up. Six months after NASA scientists first peeked inside one comet from afar, they're bringing pieces of another to Earth for study under the microscope.
This weekend, the Stardust spacecraft will jettison a 45-kilogram capsule holding comet dust. It will nosedive through the Earth's atmosphere and if all goes well and make a soft landing in the Utah desert. The searing plunge is expected to generate a pinkish glow as bright as Venus that should be visible without a telescope across much of the West.
Comets which astronomers consider to be among the solar system's leftover building blocks have been scrutinised for centuries. But only in recent years have scientists had the technology to learn first hand their ingredients. Last July, the Deep Impact spacecraft released a probe that carved a crater in a comet, exposing its interior to NASA telescopes.
The Stardust mission went a step further by retrieving the first samples from a comet named Wild 2, which was about 500 million miles from Earth when Stardust was launched in 1999. Comets are bodies of ice and dust that circle the sun. About 4.5 billion years ago, a cloud of gas and dust collapsed to create the sun and planets. Comets formed from what was left over.
First Published: Jan 10, 2006 14:04 IST