The concept has obviously been a staple of science fiction for decades (see, for example, one of my favorite Star Trek Next Generation episodes, "The Chase").
Most current research, of course, focuses on unintentional pan-spermia--chunks of whatever blown out of one solar system and ending up in another, quite by (shall we say) evolutionary accident.
"Lithopanspermia" is exactly that: Pan-spermia by chunks of rock.
It has always been a low order possibility in scientific circles, because the best calculations of the chances of random life-bearing (or life-precusor-bearing) rocks being flung from one system and ending up being captured in the gravity well of a planet in another system were (get ready for the pun) astronomically low: 1 in 1,000,000 or lower.
Turns out, however, that all of these studies and simulations had in common working with rocks ejected at high speeds.
When you simulate rocks leaving their home systems very slowly, the odds of a successful transfer between stars in the same or neighboring clusters drops to between 5 to 12 out of 10,000--it becomes 1,000 times more likely, and possibly common, say several Princeton astronomers:
"Our work says the opposite of most previous work," [Edward] Belbruno said. "It says that lithopanspermia might have been very likely, and it may be the first paper to demonstrate that. If this mechanism is true, it has implications for life in the universe as a whole. This could have happened anywhere."If this holds up, from a societal point of view this could be as disorienting to evangelical religion (both Christian and Muslim) as Charles Darwin's work on natural selection.
Both fundamentalist/evangelical Christianity and Islam depend on the Earth and human beings being the center of the universe--or at least the point of the universe.
That's why Copernicus, Giordano Bruno, Galileo, Darwin, Einstein, Dirac, and Hawking are so dangerous. Each succeeding discovery has taken humanity and Earth further and further from the center stage to being an unimportant accident in an insignificant part of a very large universe that can be explained with no reference to Her.
Lithopanspermia challenges one of the last hold-out positions for evangelical intellectuals (and, yes, there are some), the idea that in an otherwise apparently lifeless universe life on Earth is unique.
It was always a weak, statistically indefensible argument, but people will grasp at whatever reeds necessary to sustain their faith. (Ironically, I don't personally believe that Christianity depends, or ever did depend, on this sort of argument, but that's a story for another day.)
So you can expect (if this theory ever gets really substantial legs--and a variety of our investigations on Mars and the asteroids could give it those legs), that the following will be the stages of response:
The further insulation of their children and their communities from science.
Attempted suppression of the research.
Violence (I'm not kidding).