Moon Watch: Last Quarter January 2017

This morning at 09:14 the moon was at its Last Quarter phase.  This is the phase I rarely see in a dark sky since it rises close to 01:00 and becomes accessibly observable in the mid-morning hours.  Much like the First Quarter Phase, half the moon is illuminated and the terminator seems to go right through the middle of the observable lunar surface.  This allows for great viewing of the craters, terraces, mountains and valleys nearby.

One of my favourite areas of the Moon to look is the Apennine Mountains (Montes Apennius).  This mountain range contains the highest mountain on the Moon (although not its highest point).  Mons Huygens is approximately 5.5km high and is circled below in an image I took late last summer.  The eastern section of the Mare Imbrium (Sea of Rains) is also shown in the image.  Mare Imbrium is the seventh largest crater in the Solar System.  The mountains surrounding it were formed several billion years ago by uplifting caused by the impact of a proto-planet that was more than 250km wide.  The relatively smooth surface of lunar maria (Lunar Seas) formed from the lava flows that filled them more than a billion years ago.

Montes Apennius

Tonight Jupiter and the bright star Spica will be at their closest conjunction, separated by 4°, well within the same binocular field of view.

Another event happening tonight is the Royal Astronomical Society of Canada - Calgary Centre General Meeting.  This is a free event (with free parking) open to the public with lectures dedicated to astronomy.  They are always very interesting and informative.  They are held at 7:30pm on the third Thursday of every month at the Kerby Centre in downtown Calgary.  Tonight we will be treated to a keynote lecture on The Antikythera Mechanism, a Greek astronomical calculator of around 100 BC, and its place in the history of technology.