Spatial ecology goes to space: Metabiospheres

Lithopanspermia is increasingly accepted as a possible mechanism for the exchange of organisms between planets. Meteoritic impacts on inhabited planets can generate ejecta reaching escape velocity, which could carry endolithic ecosystems from the deep biosphere into space. If the ejecta travel long and fast enough they could be captured by another planet. Organisms inside the rock might survive re-entry, reaching the planet lithosphere. These processes re-enact spatial ecology at an astronomical level, for example mirroring metapopulation ecology: empty (of life) and occupied patches (planets and large moons) are separated by an inadequate matrix (space), being colonised (turned into biospheres) and perhaps suffering extinctions. As in metapopulations, we can predict this colonisation/extinction dynamics will lead to higher probabilities of life persisting longer times in a Solar System given adequate conditions. This system may be called a metabiosphere, and this ecological dynamics at an astronomical level astroecology, a new scientific branch mingling ecology and astrobiology. (c) 2014 Elsevier Inc. All rights reserved.