In the 1800s, leading scientists suggested that life might have come from space, and in fact suggested that, like giant interstellar sperm, comets might transport the seeds of life from collapsed space clouds to fledgling and otherwise barren planets, depositing their life-giving substances in a colossal impact. Up until very recently, just two leading researchers have carried the panspermia torch, which as a scientific and philosophical inquiry was shunned by schools of both science and faith.
Sir Fred Hoyle, known for his studies of star structure and the origin of the chemical elements in stars, has worked with Chandra Wickramasinghe over the past three decades to pioneer the modern theory of panspermia. In the 1970s, Wickramasinghe and Hoyle found traces of life in the dust around distant stars. The duo then broadened the panspermia theory, arguing that a continual rain of life-altering stuff from space- including germs that arrive in cycles related to solar activity- has deeply an continuously affected the wanton course of evolution.
The seeds, they say, are still coming.Wickramasinghe found that 2,200 pounds of bacterial material fall to the planet every day, some of which is �highly evolved, with an evolutionary history closely related to life that exists on Earth�. That�s 20,000 bacteria per square meter of the Earth�s surface.