“Impact gardening” is the evocative term used to describe surface disturbance—and potential biological effects—caused by the crashing of extraterrestrial objects into planetary bodies.
[Image: The surface of Europa, including “the kind of areas churned by impact gardening.”]
These impacts can “churn” or, in effect, plow the surface, exposing previously buried materials to solar radiation—which, in turn, can break down and even sterilize any life thriving there—but it can also push potential organic matter “downward, where it could mix with the subsurface,” almost like planting seeds, according to a short feature published today by NASA.
“If we hope to find pristine, chemical biosignatures,” planetary researcher Emily Costello explained to NASA, “we will have to look below the zone where impacts have been gardening.”
Distant planetary landscapes, gardened by impacts.
Read more over at NASA—I’m honestly just posting this for the poetry of the phrase impact gardening…
(Somewhat related: Life on the Subsurface: An Interview with Penny Boston.)