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Sunday, January 19, 2014


Another Image of the 16ths Mini-Moon (16 January 2014)

The  Moon imaged on 16 January with a 1/250th second exposure at ISO 1600 taken with a Pentax K10D through my 4" reflector using a a T-ring adaptor. The image is a mosaic of two images, assembled in The Gimp then I messed around with the curves feature to produce more contrast between the maria, highlands and bright rays. 

Click to embiggen for full effect (including the mosaic join line that I can't make go away).

The first full Moon of the year, on 16 January Australian time, occurred with the Moon at apogee, when the Moon is farthest in its orbit from Earth. 

This was not only the smallest full Moon of 2014, it was the smallest since the Full Moon of November 18th, 1994 and no Full Moon will be smaller until May 13th, 2052.

Comparison of the January 16 mini Moon and the August 11 "Super" Moon simulated in Stellarium.

Later this year on August 10 UT (August 11 Australian time), the Full Moon  coincides with perigee, when the Moon is closest to Earth.

On Jan 16th, the Moon was 406536 Km from Earth at furthest remove, while on August 11 it will be 356896 Km away at closest approach.

While the effect is really obvious in a telescope, visually it is very hard to see the difference even if  you have fantastic eyesight. On January the 16th 2014,  the apogee diameter was  29'32", for the perigee Moon of August 11 it will be 33'90". In both cases the Moon around half the width of your finger, and 4' (that's minutes of arc, about 4 human hairs in width) different. This is around the limit of what humans can distinguish. If you have great eyesight and and a great memory you will be able to distinguish between the January and August full Moons.

Otherwise you need a telescope and exactly the same zoom enlargement to see the difference, see Inconstant Moon for instructions. I'm planning my August shoot now. If you are thinking of taking a shot ourelf now is a good time to start planning as well, the next apogee Moon (not as good as this one), is Feb 6, 2015.

For a list of full/new Moons and the dates of apogee/perigee see here.

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