Halloween Sky Show

Oct. 28, 2008: Stop! Take your finger off that doorbell. Something spooky is happening behind your back. Turn around, tip back your mask, and behold the sunset.

It's a Halloween sky show.

On Oct. 31st, the crescent Moon will sneak up on Venus for a close encounter of startling beauty. The gathering is best seen just after sunset when the twilight is pumpkin-orange and Halloween doorbells are chiming in earnest. Venus hovers just above the southwestern horizon, the brightest light in the sky, while the exquisitely slender Moon approaches just a few degrees below: sky map.

Above: Venus and the crescent Moon photographed in July 2007 by Dan Bush of Albany, Missouri. The scene will be much the same on Halloween 2008. [Larger image]

Okay, stop staring. There's candy to be gathered.

One night later, you can give the sequel your undivided attention. On Nov. 1st, Venus and the Moon emerge from the twilight side-by-side, Venus on the right, the Moon on the left: sky map. Look carefully at the Moon. Can you see a ghostly image of the full Moon inside the bright horns of the crescent? That’s called "Earthshine" or sometimes "the da Vinci glow" because Leonardo da Vinci was the first person to explain it: Sunlight hits Earth and ricochets to the Moon, casting a sheen of light across the dark lunar terrain. A crescent Moon with Earthshine is one of the loveliest sights in the heavens.

The show continues on Nov. 2nd with Venus, the still-slender crescent Moon, and Jupiter arrayed in a broad line across the southwestern sky: sky map. This linear arrangement attracts attention almost as much as the luminosity of its points: Venus, the Moon and Jupiter are the brightest objects in the heavens, visible from light-polluted cities even before the twilight sky fades to black.

Trace your finger upward along the line—that is where the Moon is going. Nightfall on Nov. 3rd reveals the Moon transported to Jupiter: sky map. The two form a pair so tight and eye-catching, it may take your breath away.

As hard as it may be to believe, these nights of dark beauty are just a hint of things to come. The real show begins one month after Halloween when Venus, the Moon, and Jupiter converge on a tiny patch of sky no bigger than the end of your thumb held at arm's length: sky map. Dec. 1st is the best night to look, even better than Halloween.

Now that's scary.