{"id":43,"date":"2018-04-18T10:52:37","date_gmt":"2018-04-18T10:52:37","guid":{"rendered":"http:\/\/robinfo.oma.be\/?page_id=43"},"modified":"2025-03-19T18:57:07","modified_gmt":"2025-03-19T17:57:07","slug":"moon","status":"publish","type":"page","link":"https:\/\/robinfo.oma.be\/en\/astro-info\/moon\/","title":{"rendered":"Moon"},"content":{"rendered":"<section class=\"toggle\"><label>General information<\/label>\r\n<div class=\"toggle-content\" style=\"display: none;\">\r\n<section class=\"toggle\"><label>Lunation and lunation number<\/label>\r\n<div class=\"toggle-content\" style=\"display: none;\"><div data-post-id=\"2377\" class=\"insert-page insert-page-2377 \"><p>A lunation, or lunar month, is the time it takes the Moon to pass through all of the Moon phases, measured from one new moon to the next New Moon. The astronomical term for a lunation is a synodic month, from the Greek term <em>synodos<\/em>, meaning meeting or conjunction. The synodic revolution of the Moon begins each time at new moon, when the Sun and Earth are aligned on opposite sides of the Moon, and stops at the next new moon. It lasts about 29.5 days. The exact length varies slightly, due to the elliptical shape of the Moon&#8217;s orbit.<\/p>\r\n\r\n<h3>Lunation number<\/h3>\r\n<p>In astronomy, it is most common to use the <strong>Brown lunation number system<\/strong> for lunar months. This system was invented by Professor Ernest W. Brown from Yale University (USA) and presented in the book <em>Planetary Theory<\/em> from 1933, which Brown co-wrote with Assistant Professor Clarence A. Shook.<\/p>\r\n\r\n<p>Brown starts his count with <strong>lunation number 1<\/strong> at the first New Moon of 1923, which was on <strong>January 17, 1923<\/strong>. Hence, lunation numbers listed for years before 1923 are negative.<\/p><\/div><\/div>\r\n<\/section>\r\n<\/div>\r\n<\/section>\r\n\r\n<section class=\"toggle\"><label>Moon phases<\/label>\r\n<div class=\"toggle-content\" style=\"display: none;\">\r\n\r\n<table class=\"wp-block-table\"><tbody><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2019\/\">2019<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2020\/\">2020<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2021\/\">2021<\/a><\/td><\/tr><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2022\/\">2022<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2023\/\">2023<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2024\/\">2024<\/a><\/td><\/tr><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2025\/\">2025<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2026\/\">2026<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-phases-2027\/\"2027<\/a><\/td><\/tr><\/tbody><\/table>\r\n\r\n\r\n<!-- <p><a href=\"https:\/\/www.astro.oma.be\/GENERAL\/INFO\/nli008a.html\" rel=\"noopener\" target=\"_blank\">Moonphases from 1900 to 2000<\/a> (in <a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/time\/universal-time-and-legal-time-in-belgium\/\" rel=\"noopener\" target=\"_blank\">Universal Time<\/a> UTC)<\/p> <p><a href=\"https:\/\/www.astro.oma.be\/GENERAL\/INFO\/nli008b.html\" rel=\"noopener\" target=\"_blank\">Moonphases from 2001 to 2030<\/a> (in <a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/time\/universal-time-and-legal-time-in-belgium\/\" rel=\"noopener\" target=\"_blank\">Universal Time<\/a> UTC)<\/p> -->\r\n\r\n<\/div>\r\n<\/section>\r\n\r\n<section class=\"toggle\"><label>Moonrise and moonset<\/label>\r\n<div class=\"toggle-content\" style=\"display: none;\">\r\n\r\n<table class=\"wp-block-table border: 2px;\"><tbody><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2019\/\">2019<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2020\/\">2020<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2021\/\">2021<\/a><\/td><\/tr><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2022\/\">2022<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2023\/\">2023<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2024\/\">2024<\/a><\/td><\/tr><tr><td><a href=\"https:\/\/robinfo.oma.be\/en\/moon-2025\/\">2025<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/moon\/moonrise-and-moonset-in-2026\/\">2026<\/a><\/td><td><a href=\"https:\/\/robinfo.oma.be\/en\/astro-info\/moon\/moonrise-and-moonset-in-2027\/\">2027<\/a><\/td><\/tr><\/tbody><\/table>\r\n\r\n<\/div>\r\n<\/section>","protected":false},"excerpt":{"rendered":"<p>General information Lunation and lunation number Moon phases 2019 2020 2021 2022 2023 2024 2025 2026 Moonrise and moonset 2019 2020 2021 2022 2023 2024 2025 2026 2027<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":72,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/43"}],"collection":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/comments?post=43"}],"version-history":[{"count":29,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/43\/revisions"}],"predecessor-version":[{"id":4549,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/43\/revisions\/4549"}],"up":[{"embeddable":true,"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/pages\/72"}],"wp:attachment":[{"href":"https:\/\/robinfo.oma.be\/en\/wp-json\/wp\/v2\/media?parent=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}