{"id":1467,"date":"2014-03-02T00:00:19","date_gmt":"2014-03-02T00:00:19","guid":{"rendered":"http:\/\/www.skycaramba.com\/blog\/?p=1467"},"modified":"2014-03-01T16:37:38","modified_gmt":"2014-03-01T16:37:38","slug":"a-great-time-for-greatest-elongations","status":"publish","type":"post","link":"https:\/\/www.skycaramba.com\/blog\/2014\/03\/02\/a-great-time-for-greatest-elongations\/","title":{"rendered":"A great time for greatest elongations"},"content":{"rendered":"

\u00a1SkyCaramba! Weekly astronomy blog for the week ending March 8, 2014<\/em><\/p>\n

March 2014 is a great time for greatest elongations. I\u2019m talking about Mercury and Venus being at their highest above the sun in the morning sky.<\/p>\n

The angle between an object and the sun as we see them is called elongation. A planet that\u2019s rising as the sun \"\"<\/a>is setting has about 180\u00b0 of elongation. After all, it\u2019s about halfway around a 360\u00b0 dome. If the planet\u2019s high overhead at sunrise or sunset, it\u2019s about a quarter of the way around and so it has about 90\u00b0 of elongation. An object with 0\u00b0 elongation could be between us and the sun. It could also be on the other side of the sun. The moon has 0\u00b0 elongation during a total solar eclipse.<\/p>\n

Venus and Mercury never get close to 180\u00b0 elongation. Instead, they reach what\u2019s called greatest elongation. That\u2019s when they\u2019re at the greatest angle from the sun before turning around and going the other way. Mercury will be at greatest elongation on March 14 and Venus will be on March 22. Both are in the morning sky.<\/p>\n

Because Mercury is closer to the sun than Venus, its greatest elongation is less than Venus\u2019s. And because Mercury\u2019s orbit is more of an ellipse than Venus\u2019s, its angular distance from the sun varies a lot from one greatest elongation to the next.<\/p>\n

The farthest Mercury ever gets from the sun during greatest elongation is almost 28\u00b0. Its elongation on March 14 is 27.6\u00b0 west of the sun. Venus gets as far as 47\u00b0 from the sun. It will be 46.6\u00b0 west of the sun on March 22. These two greatest elongations are truly among the greatest elongations we can see!<\/p>\n

For Mercury, how great a greatest elongation is depends on the time of year. March and April are best for when the planet\u2019s visible in the morning. The best evening viewing for Mercury is when it\u2019s at greatest elongation in July, August, and September. The worst of Mercury\u2019s greatest elongations are those that happen in September and October for morning viewing, and in February for evening viewing. At those times, the planet will be just 18\u00b0 from the sun.<\/p>\n

For Venus, every greatest elongation is pretty good. They\u2019re always about 45\u00b0 to 47\u00b0, morning or evening, any time of year. But to satisfy everyone\u2019s curiosity, I\u2019ll inform you the best are in January for morning events and in November and December for evening. The worst (and I emphasize that they\u2019re not actually bad at all) are in late June and July for morning elongations and May to early June for evening. Star Venus watching and you\u2019ll eventually agree the planet never puts on a bad show.<\/p>\n

Well, take a look at Mercury and Venus for yourself this month and enjoy two really good greatest elongations.<\/p>\n

\u00a1SkyCaramba!<\/p>\n

The graphic for this page was made with Home Planet.<\/p>\n

Links to more information about this topic:
\nhttps:\/\/www.fourmilab.ch\/images\/3planets\/elongation.html<\/a>
\nhttp:\/\/astro.unl.edu\/naap\/ssm\/elongation.html<\/a>
\nhttp:\/\/themcclungs.net\/astronomy\/concepts\/plotinner.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

March 2014 is a great time for greatest elongations. I’m talking about Mercury and Venus being at their highest above the sun in the morning sky.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[88,4,17],"_links":{"self":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/1467"}],"collection":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/comments?post=1467"}],"version-history":[{"count":9,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/1467\/revisions"}],"predecessor-version":[{"id":1477,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/1467\/revisions\/1477"}],"wp:attachment":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/media?parent=1467"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/categories?post=1467"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/tags?post=1467"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}