{"id":3449,"date":"2014-02-04T22:34:10","date_gmt":"2014-02-05T06:34:10","guid":{"rendered":"https:\/\/www.wkiri.com\/today\/?p=3449"},"modified":"2014-02-04T22:34:10","modified_gmt":"2014-02-05T06:34:10","slug":"does-the-earth-rise-seen-from-the-moon","status":"publish","type":"post","link":"https:\/\/www.wkiri.com\/today\/?p=3449","title":{"rendered":"Does the Earth rise, seen from the Moon?"},"content":{"rendered":"<p>Perhaps you have seen this iconic photograph, taken by Apollo 8 astronaut William Anders in 1968:<\/p>\n<p><center><a href=\"http:\/\/en.wikipedia.org\/wiki\/File:NASA-Apollo8-Dec24-Earthrise.jpg\"><img decoding=\"async\" width=400 src=\"http:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/a\/a8\/NASA-Apollo8-Dec24-Earthrise.jpg\/400px-NASA-Apollo8-Dec24-Earthrise.jpg\"><\/a><\/center><\/p>\n<p>It is an arresting view: our Earth, seen from the outside.  But not just from afar: from another place in space.  The lunar landscape gives it a certain awe-inspiring context.  How small our Earth looks against the vast stretch of the lunar horizon!<\/p>\n<p>Yet despite its beauty, this photo has irritated me for some time.  It is titled <a href=\"http:\/\/en.wikipedia.org\/wiki\/Earthrise\">Earthrise<\/a>, a poetic and yet almost entirely misleading name.  <\/p>\n<p>How many people have seen this photo and come away thinking that the Earth rises on the Moon?<\/p>\n<p>How many still think that?<\/p>\n<p>The Earth was not rising.  The Moon is tidally locked with the Earth, which means that it always points the same face at the Earth.  From the Moon&#8217;s perspective, the Earth would hang at a fixed point in the sky, depending where you stood on the Moon&#8217;s surface.  (From the far side, you would never see it.)  <\/p>\n<p>However, the astronauts were not standing on the surface but instead in orbit around the Moon, so from their perspective, the Earth came shooting up over the horizon, an artificial Earthrise.<\/p>\n<p>BUT WAIT!<\/p>\n<p>That&#8217;s not quite right.  Today I learned that the Earth isn&#8217;t entirely stationary in the lunar sky, because <a href=\"http:\/\/en.wikipedia.org\/wiki\/Earthrise#Potential_earthrises_as_seen_from_the_Moon.27s_surface\">it (the Moon) librates (wobbles)<\/a> a little bit back and forth, which makes the Earth appear to move slowly, subtly in the sky, over the course of a month.  Perhaps more interesting to the observer is the fact that, from the Moon, the Earth goes through phases (as shown above).<\/p>\n<p>China&#8217;s Yutu rover recently captured its own &#8220;Earthrise&#8221; shot, which includes the lander, and the Earth in a different phase:<br \/>\n<center><a href=\"http:\/\/www.flickr.com\/photos\/billdavis6959\/11888475675\/\"><img decoding=\"async\" width=400 src=\"http:\/\/farm3.staticflickr.com\/2874\/11888475675_3a653fbed9.jpg\"><\/a><\/center><\/p>\n<p>Orbital geometry aside, these photos are just breathtaking.  And the idea of our blue planet rising, sailing overhead, and then setting is such a dramatic and captivating one!  But not reality.  As you now know.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Perhaps you have seen this iconic photograph, taken by Apollo 8 astronaut William Anders in 1968: It is an arresting view: our Earth, seen from the outside. But not just from afar: from another place in space. The lunar landscape gives it a certain awe-inspiring context. How small our Earth looks against the vast stretch [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[36,25],"tags":[],"_links":{"self":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts\/3449"}],"collection":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3449"}],"version-history":[{"count":6,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts\/3449\/revisions"}],"predecessor-version":[{"id":3455,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts\/3449\/revisions\/3455"}],"wp:attachment":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3449"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3449"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3449"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}