The scientist who raced against the publicly funded project to decode the human genome will soon be sequencing the genomes of all the microbes floating in New York City air.The “air genome project” was announced by Craig Venter of the J. Craig Venter Institute in Rockville, Maryland, US, on Monday. He says it could lead to the discovery of previously unknown organisms and aid biosecurity.According to Venter, siphoning off vats of smoky New York City air each day and amplifying the DNA of the fungi, bacteria and viruses it contains is the only way to uncover the mysteries of airborne microbial life. Only 1% of the microbes in the air can be identified by growing cultures in the lab, he told the New York Times, yet “it is important to understand this unseen world”. While some scientists think the idea is “crazy”, others are fascinated. “Whenever you take on a project of this scale, you are going to discover new things - there is so much we still don’t know about microbiology,” says Jeffrey Blanchard, a microbiologist at the University of Massachusetts, Amherst, US, who is currently decoding the genome of cyanobacteria in the Sargasso Sea, off Bermuda."This is one of those Venter adventures, but I can’t make up my mind whether something will come of this or not,” says Eckard Wimmer of the State University of New York at Stony Brook, US. He points out that simply sequencing a microbe’s genome does not automatically reveal whether it is infectious.