astroplankton
now historical
noun
Hypothetical living material such as microorganisms or spores present in space, postulated as able to initiate or spread life on reaching a suitable environment.
- Suggested by J. B. S. Haldane as a technique by which intelligent extraterrestrial beings could propagate living organisms..
Origin
1950s; earliest use found in John Burdon Sanderson Haldane (1892–1964), geneticist.