Moonquakes Surprisingly Common
影像提供: Neil Armstrong, Apollo 11 Crew, GRIN, NASA
Explanation:
Why are there so many moonquakes? A recent reanalysis of seismometers left on the moon by the Apollo moon landings has revealed a surprising number of moonquakes occurring within 30 kilometers of the surface. In fact, 28 moonquakes were detected in data recorded between 1972 and 1977. These moonquakes were not only strong enough to move furniture but the stiff rock of the moon continued vibrating for many minutes, significantly longer than the soft rock earthquakes on Earth. The cause of the moonquakes remains unknown, with one hypothesis holding that landslides in craters cause the vibrations. Regardless of the source, future moon buildings need to be built to withstand the frequent shakings. Pictured above in 1969, Apollo 11 astronaut Buzz Aldrin stands besides a recently deployed lunar seismometer, looking back toward the lunar landing module.
說明:
為何月震會如此之多？最近在重新分析阿波羅登月計畫留在月球的月震儀之數據後，意外發現月表表層三十公里內有相當數量的月震。1972年到1977年之間的數據，共記錄了28次的月震。這些月震不但強烈到能移動傢俱，而且讓月球硬岩震動了許多分鐘，遠長於地球軟岩地震的持續時間。月震的成因不明，其中一種假說認為隕石坑邊坡的崩塌造成了這些震動。不論源頭為何，未來的月球建物要能承受經常發生的月震。在上面這張1969年影像裡，阿波羅十一號的太空人艾德林站在剛架設之月震儀旁，面向著登月艙。
資料來源: Scientific American
Department of Physics, NCKU
