秤動
thumb|The lunar phases and librations in 2019 in the Northern Hemisphere at hourly intervals, with music, titles, and supplemental graphics alt=Over one lunar month more than half of the Moon's surface can be seen from the surface of the Earth.|thumbtime=0:02|thumb|Simulated views of the Moon over one month, demonstrating librations in latitude and [[longitude. Also visible are the different phases, and the variation in visual size caused by the variable distance from the Earth.]] thumb|Theoretical extent of visible lunar surface (in green) due to libration, compared to the extent of the visib
AI overview
Libration is a slight rocking or wobbling motion that allows us to see slightly more than half of the Moon's surface over time, even though the same side always faces Earth. This matters because it means that from Earth, we can eventually observe about 59% of the Moon's surface rather than just 50%, giving us a more complete view of our nearest celestial neighbor.
AI-generated from the Wikipedia summary — may contain errors.
Wikidata facts
- Image
- Lunar libration with phase Oct 2007 (continuous loop).gif
Sources (1)
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Article · 日本語
秤動（ひょうどう、libration）とは、ある天体からその周囲を公転する衛星を見た時に、その衛星が見かけ上行うように見える、または実際に行うゆっくりとした振動運動である。単に「秤動」と言う場合には特に、地球を周回する月の秤動を指すことが多い。 なお、「秤動」という漢字表記は、正しくは「ショウドウ」と音読するべきところであるが、これを「ヒョウドウ」と読むのは、「章動」（ショウドウ）、「摂動」（ショウドウ、セツドウ）と区別するためであるという。
Abstract from DBpedia / Wikipedia · CC BY-SA