Astropedology symposia are a new focus for scientific meetings on soil science.[3] Advancements in understanding the chemical and physical mechanisms of pedogenesis on other planetary bodies in part led the Soil Science Society of America (SSSA) in 2017 to update the definition of soil to: "The layer(s) of generally loose mineral and/or organic material that are affected by physical, chemical, and/or biological processes at or near the planetary surface and usually hold liquids, gases, and biota and support plants".[4]