871 at a meeting of tision for t ofScience  “t  to teorite.” But it remained little more tion until one Sunday inSeptember 1969 ralians artled by a series of sonicbooms and t of a fireball streaking from east to  across trange crackling sound as it passed and left be some likened to metedspirits and ot awful.

    tounately, no one eorite ype knooiming could ter. Less tronauts urned to Eart traterrestrial origin.

    teorite o be 4.5 billion years old, and it udded y-four types in all, eigion of earteins. In late 2001, more ty years after it craseam at ter in California announced t tained complex strings ofsugars called polyols, h before.

    A fees rayed into Eart landednear tagiss of Nort tually ric, it is no, is about 25 percent organic molecules. Getenougo a suitable place—Eartance—and you s you need for life.

    tions of panspermia, as extraterrestrial theories are known.

    t is t it doesn’t ansions about  merely movesresponsibility for it elseimes excites even trespectable ads to levels of speculation t can be safely called imprudent. FrancisCrick, codiscoverer of tructure of DNA, and edt Eartely seeded elligent aliens,” an idea t Gribbin calls“at tific respectability”—or, put anotion t ic if not voiced by a Nobel laureate. Fred ing t outerspace broug only life but also many diseases suc o insert areminder   scientific minds of tietury—alsoonce suggested, as mentioned earlier, t our noses evolved rils underneato ted down from space.

    ever prompted