Topline<\/p>\n
This weekend ends May with a rare occurrence \u2014 a second full moon in a single calendar month, a calendrical phenomenon commonly known as a Blue Moon. While the term has nothing to do with color, it will have many people looking for the full moon who usually ignore it, and many of them will miss it. There are two reasons for that. Non-experts are saying that the Blue Moon is on Sunday, May 31, but as any moon gazer knows, by far the best moment to see a full moon is not when it\u2019s high overhead, but when it appears low on the horizon just after sunset. That happens during dusk on Saturday, May 30. Here\u2019s everything you need to know about this weekend\u2019s Blue Moon. <\/p>\n
May’s Flower Moon shines through the trees in Tennessee.<\/p>\n
gettyTimeline<\/p>\n
Friday, May 29The 98%-lit nearly full moon is already high in the eastern sky by sunset, appearing large and bright. As it rises, look below it for Antares, the brightest star in the summer constellation Scorpius. <\/p>\n
Saturday, May 30It\u2019s the best evening to watch moonrise for the full Blue Moon effect. Find an unobstructed southeastern horizon at the time of moonrise where you are,<\/a> and you\u2019ll see a large, orange full moon appear. You\u2019ll soon see Antares just below it. Much closer than on Friday. Why tonight? The moon rises as the sun sets, which creates a dramatic effect.<\/p>\n Sunday, May 31During the night, at 4:45 a.m. EDT, the Blue Moon will become official as the lunar surface becomes 100% lit by the sun. However, tonight it will rise around an hour after the sun has set, as seen from North America.<\/p>\n What Makes A \u2018blue Moon\u2019<\/p>\n A blue moon is simply the second full moon in a calendar month, a consequence of the moon\u2019s 29.5-day cycle not aligning perfectly with our calendar. It happens every two to three years, making it relatively uncommon \u2014 but not rare. The next time this kind of \u201cmonthly\u201d blue moon will take place is Dec. 31, 2028, according to TimeAndDate.com<\/a>. That will also be a total lunar eclipse.<\/p>\n What matters is timing. Because this full moon rises close to sunset, Saturday, May 30, offers the perfect opportunity to watch it emerge against a landscape, giving it scale and color that are lost when it climbs higher. For urban observers, this is one of the easiest and most reliable sky events of the year. No dark skies required \u2014 just timing and a clear view to the east.<\/p>\n Why The Blue Moon Is Orange<\/p>\n The term Blue Moon relates to the rarity of having two full moons in one calendar month, and is not related to its color. Just as the sun at sunrise and sunset appears a deep orange, so too does the full moon at moonrise and moonset. Why? Visible light is a form of electromagnetic radiation, which is made up of photons \u2014 particles of light \u2014 that travel in different wavelengths. Earth\u2019s atmosphere scatters light, deflecting photons off molecules of nitrogen and oxygen. Blue has the shortest wavelengths of light, which more easily strike molecules and scatter more readily. Red has the longest, so more of its travels through Earth\u2019s atmosphere unimpeded. The phenomenon is called Rayleigh scattering<\/a> and is named after Lord Rayleigh (John William Strutt), a British physicist, who wrote a paper about it in 1871.<\/p>\n What\u2019s Next In The Night Sky<\/p>\n Between June 9-11, Venus and Jupiter come together in a striking conjunction low in the western sky after sunset \u2014 one of the standout naked-eye events of the year. The new moon on June 15 brings a brief period of dark skies before the June solstice on June 21 ushers in the shortest nights of the year for the northern hemisphere.<\/p>\n The times and dates given apply to mid-northern latitudes. For the most accurate location-specific information, consult online planetariums like Stellarium<\/a>.<\/p>\n Further ReadingForbesIn Photos: Full \u2018Flower Moon\u2019 Lights Up Night Sky Around The WorldBy Jamie Carter<\/a>ForbesWhat Is That Bright Star In The West After Sunset?By Jamie Carter<\/a>ForbesIt\u2019s 100 Days Until A Total Solar Eclipse. Here\u2019s How To See ItBy Jamie Carter<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Topline This weekend ends May with a rare occurrence \u2014 a second full moon in a single calendar…\n","protected":false},"author":3,"featured_media":830158,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[8],"tags":[51717,340699,340702,340701,336156,159,340700,67,132,68],"class_list":["post-830157","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-blue-moon","tag-blue-moon-may-2026","tag-full-moon-weekend-sky","tag-moonrise-stargazing","tag-night-sky-this-weekend","tag-science","tag-second-full-moon-may-31","tag-united-states","tag-unitedstates","tag-us"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116658159637259183","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/830157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=830157"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/830157\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/830158"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=830157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=830157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=830157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}