What’s Up in the Sky July, 2009
By Peter Burkey
Inexperienced stargazing enthusiasts often think that this time of year is the best for observing. Warm weather, clear skies, and vacation time all offer the potential for great stargazing. To the serious amateur, however, July translates into hot, humid, hazy nights with bugs and skies that are not dark until 10:30 p.m. But, hey, this is an astronomy column, so I certainly don’t want to put a damper on your stargazing enthusiasm. Grab the insect repellent, plan for a late night, and do some naked eye or binocular observing.
If you are an early riser, see if you can catch the planets Venus, Mars and Jupiter in the predawn sky. You can’t miss Venus shining like a beacon in the east before sunrise. Early in the month, around 5:00 a.m., you should be able to spot Venus in a line with Mars to its upper right and the star Aldebaran to its lower left. On the 14th, look for the two planets between the Hyades and Pleiades clusters in the constellation Taurus. On July 18 and 19 these four objects are joined by the waning crescent Moon – a lovely gathering indeed. On the 26th, Mars is now closest to Aldebaran, forming a skinny triangle with Venus to their lower left.
Meanwhile, Jupiter is the second brightest object in the sky (other than the Moon) and can be found due south at 5:00 a.m. early in the month. It is joined by a gibbous Moon on the 10th. However, you don’t have to get up before dawn to see Jupiter as it rises in the east before midnight on July 1 and around 10:00 p.m. by month’s end. And you can always observe its four largest satellites with a small telescope or large binoculars.
Speaking of small telescopes, if you haven’t seen Saturn’s rings lately, catch them this month because soon they will be invisible as they will appear edge-on from our vantage point. Use a telescope and look above the western horizon after sunset.
This month in history:
July 1: Wernher von Braun retires from NASA – 1972
July 5: Space Shuttle Challenger arrives at KSC for first time – 1982
July 10: First transatlantic TV signals made possible by launch of Telstar – 1962
July 17: First photograph of a star – 1850
July 19: Christa McAuliffe selected to be first private citizen in space – 1985
July 20: First humans walk on Moon – 1969
July 28: First photo of total solar eclipse – 1851
Here are this month’s viewing highlights:
Planets this month: Venus and Mars rise 60 – 90 minutes before sun in East. Saturn is low in West after sunset. Jupiter rises around midnight and is low in SW at dawn.
July 4: Earth reaches aphelion – the point in its orbit farthest from the sun
July 7: Full Moon.
July 15: Last-quarter Moon.
July 19: Crescent Moon joins Venus and Mars 2 hours before sunrise in ENE.
July 21: New Moon. Longest total solar eclipse of 21st century visible in India and China.
July 28: First-quarter Moon. Mars closest to Saturn.