Impact-generated hydrothermal systems on Earth and Mars

► Impact-generated hydrothermal activity is commonplace on Earth and likely Mars. ► Hydrothermal deposits may be found in six settings within and around impact craters. ► Impact-generated hydrothermal systems may provide important habitats for life. ► New evidence for impact-generated hydrothermal systems on Mars is presented. ► Hydrothermally altered rocks provide nutrients and habitats for life after activity has ceased.