The argument that life on Earth may have been seeded from the stars just received a major boost, as scientists have found the building blocks of life inside a meteorite that landed in British Columbia in 2000.

The Tagish Lake meteorite landed in January of that year, a streaking fireball that burst into more than 500 fragments which rained down on the lake. In its trip from the outer reaches of the asteroid belt it burned down from 56 tonnes to 1.3, and deep inside the fragments there are the basic building blocks of life, including the amino acids, sugars and hydrocarbons that could have jump started life on our planet.

This meteorite is the only uncontaminated example we’ve ever found, thanks to the quick actions of the people who spotted it. What the researchers have found is that the organic compounds in the rock date back to…

Rather than looking for aliens who use interstellar radio signals to say “hi,” an alternative search strategy is simply to spy on any mega-engineering projects that an advanced civilization might be undertaking. Veteran SETI astronomer Jill Tarter calls this strategy “SETT” — the Search for Extraterrestrial Technology.

A new science paper by Duncan Forgan at the University of Edinburgh in Scotland and Martin Elvis at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., suggests we look for evidence of a very ambitious macro-engineering project: the wholesale mining of an asteroid belt. The asteroid material may be mined to build space colonies, solar power satellites or maybe even an entire “ringworld,” as imagined by sci-fi writer Larry Niven.

What’s more, precious metals are in high demand for technologies such as computers, high-speed networks and mobile phones. So-called “green technologies” of the future, such as hydrogen fuel cells, will…

Ebay and other Web sites pulse with hundreds of sales pitches. “The pieces below have an exceptional patina,” a site called Star-bits.com said of 10 pictured fragments.

The ads are for chunks of meteorites, bits of asteroids that have fallen from the sky and are as prized by scientists as they are by collectors. As more meteorites have been discovered in recent years, interest in them has flourished and an illegal sales market has boomed — much to the dismay of the people who want to study them and the countries that consider them national treasures.

“It’s a black market,” said Ralph P. Harvey, a geologist at Case Western Reserve University who directs the federal search for meteorites in Antarctica. “It’s as organized as any drug trade and just as illegal.”

The discovery of a rich and historically…