https://www.space.com/38922-extraterrestrial-bacteria-international-space-station.html Scientists have detected living bacteria "from outer space" in samples collected from the exterior of the International Space Station (ISS) during spacewalks, cosmonaut Anton Shkaplerov told Russia's state-owned TASS news agency. Now lets replace the ISS with asteroids. Well that wouldn't work because the asteroids would probably be pulled into the planet because they are so close it. What I am getting at is there seems to be a possible wave that carries the components through for bacteria to grow from. Much like a solar wind travels through space the wave would carry the components from their point of creation until they came into contact with minerals that would allow them to feed off of other material that becomes trapped in the crevices of the mineral's structure. Water would also need to be present so possibly these bacteria could have come from Enceladus which has plumes of water that shoot out from its surface at various times. Possibly frozen in very small water droplets that have Enceladus surface material mixed in with the droplet of water. A brown paper bag lunch if you will. Once the droplet of water comes close to a source of heat or an EM field such as the Earth's own EM field, the droplet would begin to melt allowing the tardigrade to wake up and feed until it comes into contact with organic material where it would then begin the process associated with engineering life on a planet such as Earth. Perhaps the Tardigrade might be the Universe's gardeners that till the garden of the Universe for other life grow from.