This month, we will feature Earth first. On July 6, at 2:06 p.m. MDT, the Earth reaches aphelion or the farthest it gets in its orbit from the Sun. The distance will be 94,506,364 miles or 152.1 kilometers which is about 3.4% farther than it was at perihelion in January.

Venus and Mars continue to hang together in the west in the early evening sky as they both continue their slow but steady progress towards the western horizon. On the first of July the pair will be only 3.5 degrees apart at about an hour after sunset. Venus, shining at magnitude -4.7, will vastly outshine Mars which will be at magnitude +1.7. You may have to wait for it to get a bit darker to be able to find Mars with your naked eye. Using binoculars might help.

Mercury also appears in the evening sky just above the western horizon. On July 19, at the midpoint of its early evening appearance, it will be slightly below and to the right of Venus. Shining at magnitude -0.4, it should be fairly easy to find. Again, binoculars may prove useful.

Jupiter and Saturn continue their westward journey in the early morning sky this month. Saturn should appear above the east-southeast horizon around 3 a.m. local time and will rise in tandem with the waning crescent moon on July 6. On July 11, the waning crescent moon will lead Jupiter by about 6 degrees as the pair rises above the east-southeastern horizon. On July 12, their positions are reversed as Jupiter will lead the moon by about 6 degrees.

The moon will be full on July 3, last quarter on July 10, new on July 17, and first quarter on July 25. Looking east on July 12, about an hour before sunrise, the waning crescent moon will be to the left and below Jupiter. Looking west on July 19, about 30 minutes after sunset, the new crescent moon will be just above Venus and Mercury. On July 19, in the same direction and time, the crescent moon will be just to the right of Mars.

There will not be a first Saturday star party at the Etscorn Campus Observatory in July.

Clear Skies!

Jon Spargo
New Mexico Tech Astronomy Club
July 2023

Jon Spargo, New Mexico Tech Astronomy Club