The Sky This Week: Venus and Mars meet for a conjunction
Friday, July 9
Moon, Venus, and Mercury: In October 2011, the Moon, Venus, and Mercury shared a small region of sky. A similar event occurs this week, but it will bring the two planets even closer.
New Moon occurs at 9:17 A.M. EDT. A moonless night is the best time to challenge yourself and your telescope, so tonight, set your sights on one of the most famous objects in the constellation Sagittarius: M20, the Trifid Nebula.
By two hours after sunset, the sky should be dark enough to begin your search. You’ll find M20 above the spout of the Teapot asterism, about 7.5° due north of 3rd-magnitude Alnasl (Gamma [γ] Sagittarii). The nebula is centered on the double star HN 40, whose components glow at magnitude 8 and 9. When observing this faint object, the size of your telescope will determine the amount of detail you can see. Mid-sized telescopes will show the Trifid as a hazy cloud surrounding the two st...