{"id":128,"date":"2011-03-20T00:00:15","date_gmt":"2011-03-20T00:00:15","guid":{"rendered":"http:\/\/www.skycaramba.com\/blog\/?p=128"},"modified":"2011-03-27T00:08:07","modified_gmt":"2011-03-27T00:08:07","slug":"viewing-mercury-made-somewhat-easy","status":"publish","type":"post","link":"https:\/\/www.skycaramba.com\/blog\/2011\/03\/20\/viewing-mercury-made-somewhat-easy\/","title":{"rendered":"Viewing Mercury made somewhat easy"},"content":{"rendered":"

\"\"<\/a>SkyCaramba astronomy blog for the week ending March 26, 2011.<\/em><\/p>\n

Mercury is at greatest elongation this week. That means it\u2019s as far as it gets from the sun in the sky before it heads back toward the sun. Mercury\u2019s usually hard to spot because it\u2019s always so close to our home star. This week is the best time to see it for about six weeks.<\/p>\n

This week, look to the west a little after sunset to see the messenger planet. Mercury is in Pisces. That\u2019s a dim constellation and there\u2019s still some twilight, so there aren\u2019t any guide stars to help. The good news is, if you see a bright dot that seems to be by itself, there\u2019s a good chance it\u2019s Mercury. .<\/p>\n

Many amateur astronomers rarely see Mercury. If there are clouds or bright lights on your western horizon, you\u2019ll have trouble. And a line of trees or houses will easily block the view.<\/p>\n

If you see something, positive identification can be made by looking at it in a telescope. This week, Mercury will look like the moon does just a day or two before first quarter\u2014more than a crescent but a little less than a semicircle. Mercury looks like that for the same reason a five-day old moon does. The sun is lighting it from the side a little to the back. You can simulate the effect by holding a ball in one hand and a flashlight in the other in a dark room. Hold the ball a little closer while the flashlight is pointed at it.<\/p>\n

Viewers from 31 degrees north latitude will get the best views of Mercury this time. That would be far northern Mexico, the Gulf states, Mediterranean Africa, the Middle East, and places east of there to east central China. Southern Japan isn\u2019t too poorly placed for it.<\/p>\n

Mercury is a gray, airless world. I was in an astronomy class in which the teacher showed a slide of the planet and announced, \u201cMercury in living black and white\u201d. Then he said he was kidding. It was actually a color photo.<\/p>\n

The planet takes just 88 Earth days to go around the sun. Because Earth is orbiting too, it takes a little longer for Mercury to reappear at close to the same spot in our sky. That\u2019s called the synodical period. Mercury\u2019s synodical period averages 116 days.<\/p>\n

The next evening greatest elongation of Mercury will be July 20. It will be better. If you can\u2019t wait that long but can handle getting up early, you can see a good morning greatest elongation around May 7.<\/p>\n

The other planet that has greatest elongations is Venus. Neither is so far from the sun as to be up all night, because they\u2019re closer to the sun than Earth. So, they can never be on the opposite side of our planet as the sun. Venus, currently a morning object, will be at greatest elongation in the evening on August 16. It\u2019s farther from the sun, so it stays up after sunset longer.<\/p>\n","protected":false},"excerpt":{"rendered":"

Mercury’s hard to spot, but you have a fair chance this week.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[88,4,16,90,89,91,17],"_links":{"self":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/128"}],"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=128"}],"version-history":[{"count":12,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/128\/revisions"}],"predecessor-version":[{"id":157,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/128\/revisions\/157"}],"wp:attachment":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/media?parent=128"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/categories?post=128"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/tags?post=128"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}