Following the Moon’s Lighttesttest
The moon reappears in our evening skies Thursday as a thin crescent low in the southwest at dusk. Lined up to the west is the twinkling blue-white star Spica and beyond that golden Saturn.
Friday the moon is just a few degrees below the second-magnitude star Zubenelgenubi, the fulcrum of the celestial scale Libra. Saturday the moon stands before Scorpius, with its red heart Antares trailing less than 10 degrees from the moon. The next evening, it is the red star that leads the first-quarter moon by a half-dozen degrees.
Monday and Tuesday, the waxing gibbous moon is to either side of teapot-shaped Sagittarius. At the dawn of civilization, the Babylonians saw this constellation that traveled the path of sun, moon and planets as the celestial archer, with drawn bow pointing toward Antares.
Looking at the shoulder of Sagittarius you are staring at the center of our own Milky Way galaxy. While you may have to stretch your imagination to see the form of the archer, this is one of the most star-rich stretches of the heavens, and astronomers now believe the home of an immense black hole.
This first week of September provides the best early morning viewing of Mercury all year. So close to the sun, the planet never strays far from its blinding glare. When it does escape, it never climbs more than a couple dozen degrees above the horizon and remains visible for a couple hours at best. Even so, it shines with a sun-baked fury, dimmer than only the planets Venus and Jupiter.
Look for ruddy Mars high above Mercury. The red planet rises in the northeast around 2am and is high in the east with sunrise, around 6:35 this week. Less than 10 degrees to the right of Mars are the Gemini twins, orange Pollux, looking much like Mars, and white Castor.
Jupiter rises around 10pm, but by around 4am it is ablaze almost directly overhead.