The moon is at last quarter at the beginning of July, so an early morning object. Uranus is two degrees north July 4. By July 8, Mercury shows up four degrees south of a thin crescent, shortly before the moon is new July 9, beginning a new 鈥渓unation鈥� 鈥� number 1,219.
The lunation number is the number of times the moon has circled the Earth since January 1923, based on work by Ernest W. Brown (1866鈥�1938). His life鈥檚 work was the study of the 鈥檚 motion and the compilation of extremely accurate lunar tables.
Now begin events in the evening western sky, as Venus and Mars join up with Luna July 12. The moon is full July 23 with Saturn four degrees north on the same day. July 26, Jupiter is four degrees north.
Mercury reaches greatest elongation west July 4, gradually brightening as it moves along its orbit to behind the sun in late July. The moon is four degrees north July 8.
Venus is in the western sky after sundown, moving along its orbit from behind the sun, but gradually getting lower to the horizon. Mars is just 0.5 degrees away July 13, with the brilliant Venus shining 200 times brighter than the Red Planet. The moon passes the pair July 11/12. July 21, Venus passes 1.2 degrees north of Regulus.
Mars is a western evening object along with Venus as noted above. It鈥檚 at it鈥檚 most distant from Earth, and at its least brightness, increasingly more difficult to see in the twilight. Mars passes Regulus July 29.
Jupiter has been retrograding, moving westward among the stars of Aquarius. The giant planet reaches opposition next month, so is visible all through the night. The moon passes by July 25/26.
Saturn, too, is nearing opposition in August, and is ever more prominent in the night sky, crossing from east to west all night. The full moon glides by on the night of July 24.
Uranus is briefly visible in the morning dawn sky, until sunlight brightens the sky.
Neptune is visible with telescopic aid in the night sky.
The southern Delta Aquariid meteors peak July 28/29.
James Edgar has had an interest in the night sky all his life. He joined the Royal Astronomical Society of Canada in 2000, was national president for two terms, is now the editor of Observer鈥檚 Handbook, and production manager of the bi-monthly RASC Journal. The IAU named asteroid 1995 XC5 鈥�(22421) Jamesedgar鈥� in his honour and he was recently awarded a Fellowship of the RASC.
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