I read this online today:
“NASA also reported that almost all water present in Jupiter’s stratosphere, an intermediate atmospheric layer, originated from comet Shoemaker-Levy 9, which gave quite a show in 1994 when it impacted Jupiter’s atmosphere.”

Comet Shoemaker-Levy 9 brought water and organic molecules to Jupiter and in so doing seeded Jupiter with the ingredients needed for the formation of life. Does that make comets sperm and planets eggs in the cosmic scheme of things?
Read the article at:

http://www.zdnet.com/hubble-brings-closer-look-at-our-amazing-comet-7000014423/#photo