The Soviet space probes Venera 15 and 16 circled in the mid-1980s and provided important information indicating a complete absence of plate tectonics on the planet.
Isikhala saseSoviet siphenya iVenera 15 ne-16 ezungezwe maphakathi nawo-1980 futhi sanikeza imininingwane ebalulekile ekhombisa ukungabikho ngokuphelele kwama-plate tectonics emhlabeni.