London, March 4 (ANI): A team of scientists has said that they have caught the first pieces of interstellar dust - the fundamental building blocks of the Sun, the Earth and the rest of the solar system.
According to a report in Nature News, the discovery required an army of volunteers, including a Canadian man who spent 15 hours a day studying images online and eventually won the interstellar lottery.
The minute specks of dust were collected by NASA's Stardust spacecraft, which launched in 1999 with the aim of catching pristine interstellar grains and returning them back to Earth.
The discovery validates four years of effort from more than 27,000 volunteers around the world, who searched 71 million images of the material captured in the Stardust collecting trays.
The two probable dust particles found so far could mark the beginning of an analysis of what stars and planets really are made of, and also offer a way of charting the chemical evolution of the Milky Way.
"The interstellar dust is fundamentally the stuff we're made of," said University of California at Berkeley scientist Andrew Westphal, who announced the discovery on March 3 at the Lunar and Planetary Science Conference near Houston, Texas.
"We're trying to understand our own origins," he added.
The researchers hoped to catch 100 or so interstellar grains from the weak but continuous flux in open space.
The elements in these grains were forged in stars, but coalesced into grains in the empty space between stars, where they were mixed and rocked by supernova shockwaves and cosmic rays.
The grains were far harder to catch than the comet particles.
Not only was the flux much lower, but the interstellar particles were smaller than the comet grains and were moving several times faster - up to 30 kilometres per second.
The Stardust researchers say that the interstellar grains nabbed by their spacecraft may provide a unique way to study the matter between stars.
"It's kind of a grand thing," said Don Brownlee of the University of Washington in Seattle, who was principal investigator for the mission. "We're catching a piece of the galaxy," he added.
"I'm cautiously excited," said Westphal, who added that the researchers must conduct more tests to ensure that their particles are truly interstellar grains, rather than micrometeorites or even pieces of the spacecraft knocked loose by debris. (ANI)