Supermoon
From the author of Sizing Up The Universe
Click here to see animations of the Moon showing its varying apparent size and its oscillatory libration.
The moon's orbit about the Earth is not a perfect circle---it is a bit eccentric (just like me). As a result, during part of its orbit it is a little closer to us than at other times. The closest approach is called perigee. The greatest separation is called apogee. On average, the moon's distance is 385,000 kilometers. At perigee it is about 350,000 kilometers away, whereas at apogee it is about 406,000 kilometers away.
Shown below is a pair of pictures of the Moon taken with the same equipment. When the Moon is close, it appears larger than when it is further away.
A full Moon at perigee is called a SUPERMOON.
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Distance = 399,686 km 22:09 EST, Feb 3, 2015 Canon XSi (450D) on 10" RC Two panel mosaic. Each panel a stack of 4 images. |
Distance = 353,615 km 23:30 EDT, Aug 9, 2014 Canon XSi (450D) on 10" RC Five 4-panel mosaics. Various exposures at ISO 200 and 800. |