More about the Moon:<\/strong><\/em><\/p>\n Earth\u2019s tides are largely influenced by the gravitational pull of the Moon, or to be more precise, between the gravitational workings of the Sun-Earth-Moon system.<\/p>\n There are two high tides and two low tides per lunar day, but why? What is causing this regularity along Earth\u2019s coastal regions, and what role does the Moon play?<\/p>\n To understand this, we have to think a bit more deeply about the gravitational relationship between Earth and the Moon.<\/p>\n The Moon\u2019s gravitational pull on the oceans is stronger on the side of Earth closest to the Moon than it is on the opposite side.<\/p>\n But there is another force, which is the same everywhere on Earth\u2019s surface, that opposes the Moon\u2019s gravitational pull, called the \u2018centripetal force\u2019.<\/p>\n We say that the Moon orbits Earth, but actually they both orbit a point that lies within the Earth.<\/p>\n The centripetal force is the force that keeps the Earth moving in a small circular orbit around this point.<\/p>\n If this centripetal force is subtracted from the Moon\u2019s gravitational attraction at different points on the Earth\u2019s surface, we are left with a \u2018differential gravitational field\u2019.<\/p>\n This field has a net force acting towards the Moon on the side of the Earth closest to the Moon, and a smaller net force away from the Moon on the other side, which gives two tidal bulges.<\/p>\n Thus, the daily rotation of the Earth produces two high tides and two low tides every 24 hours and 50 minutes.<\/p>\n This article originally appeared in the October 2007 issue of <\/strong><\/em>BBC Sky at Night Magazine<\/strong>.<\/strong><\/em><\/p><\/body><\/html>\n By Garry Hunt Published: Saturday, 29 January 2022 at 12:00 am The Moon\u2019s effect on Earth can\u2019t be ignored. It\u2019s our closest celestial neighbour and has inspired and intrigued stargazers for as long as there have been human beings to look up at the night sky. But it also has a very real and tangible […]<\/p>\n","protected":false},"author":24,"featured_media":28794,"template":"","categories":[1],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day.jpg",2148,1396,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-300x195.jpg",300,195,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-768x499.jpg",768,499,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-1024x666.jpg",800,520,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-1536x998.jpg",1536,998,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/01\/why-are-there-two-high-tides-and-two-low-tides-every-day-2048x1331.jpg",2048,1331,true]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Garry Hunt Published: Saturday, 29 January 2022 at 12:00 am The Moon\u2019s effect on Earth can\u2019t be ignored. It\u2019s our closest celestial neighbour and has inspired and intrigued stargazers for as long as there have been human beings to look up at the night sky. But it also has a very real and tangible…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/28793"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/28794"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=28793"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=28793"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\""Diagram\"](\""https:\/\/images.immediate.co.uk\/production\/volatile\/sites\/25\/2022\/01\/gravitational-force-moon-earth-8ee4577.jpg?quality=90&resize=620%2C317"\" "\\"\"gravitational\\"")
<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>![\""A\"](\""https:\/\/images.immediate.co.uk\/production\/volatile\/sites\/25\/2022\/01\/moon-earth-centripetal-tidal-bulges-da494ec.jpg?quality=90&resize=620%2C340"\" "\\"\"moon\\"")
<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
","protected":false},"excerpt":{"rendered":"