July Skies On The Horizon

By Jon Spargo
New Mexico Tech Astronomy Club

We are told that the word ‘planet’ is Greek in origin and translates into ‘wanderer.’ This month a better term to describe our planetary parade might just be groupies or congregation. All of the action seems to be happening in the western sky, just above the horizon and about an hour after sunset.
The fun begins on the 1st and starts with brilliant Venus shining at magnitude -4.2. From Venus you can draw an imaginary straight line up and to the left that will encounter the bright star Regulus in Leo and continue on to both Mars and Saturn.
As the days progress, and using the star Regulus as a reference, watch as the planets change positions relative to each other. On the 9th Venus will catch and pass Regulus seemingly exchanging positions in our imaginary line. On the 13th we can add tiny Mercury to our planetary lineup.
Mercury will put in a fairly extensive appearance although it will never get much more than 7 degrees above the horizon. On the 27th Mercury will be about ½ degree from the bright star Regulus and can be found about 10 degrees below and to the right of Venus.. However, you will probably need binoculars to pick out this pair which are near the horizon.
Not to be left out, Saturn and Mars will form a close pair at the end of the month. Separated by 2 degrees on the 29th they will be the closest, 1.8 degrees, on August 1st. As it moves slowly toward the western horizon Saturn will be worth viewing through binoculars or small telescopes as its rings continue to slowly open.
With all of the early evening activity in the west, we shouldn’t forget magnificent Jupiter. At the beginning of the month Jupiter rises around midnight, about the same time Saturn sets, and will rise around 10:30 p.m. by the end of the month. Shining at magnitude -2.7, Jupiter will be spending most of the month well placed above the celestial equator. If you have a decent pair of binoculars, look 2 to 3 degrees west of Jupiter and you’ll probably be able to pick out the planet Uranus.
The Moon will be last quarter on the 4th, new on the 11th, 1st quarter on the 18th and full on the 25th. On July 8th, about an hour before sunrise, the waning crescent Moon will be found about 2 degrees below the famous Pleiades (the 7 sisters) star cluster. During the early evening hours of the 13th through the 16th the waxing crescent moon passes below a congregation of planets that include Mercury, Venus, Mars and Saturn. On the 30th the waxing gibbous Moon will be about 6 degrees above Jupiter.

July Skies On The Horizon