March Zodiacal Light

Last month I mentioned Zodiacal Light, but I never saw it even though I looked at Venus every night. March is predicted to be the best month to look for it, so this is the month I will tell you about it. Since the last quarter moon is on the 15th and the new moon is on the 21st, this is the perfect time to look for it and observe the entire sky.

As I am sure you know, Venus dominates the SW sky for several hours after sunset. It reaches its greatest elongation east of the Sun on March 24, which keeps it in the sky for the longest time. It also sits in front of the Zodiacal Light. So about 1 ½ hours after the Sunset when you look at Venus, you should also see the Zodiacal Light.

It is a tilted wedge of glowing comet and asteroid debris centered on the ecliptic that towers in the SW sky from late winter to spring. With no moon visible, this luminous branch of interplanetary dust extends about 300 degrees wide and 60 degrees high, making it appear around two-thirds of the way up in the sky.

It is made of trillions of dust particles from comets passing near the Sun, and debris left from colliding asteroids that accumulate within the ecliptic plane and supply the materials that glow. It extends from the Sun to past Mars, and scatters Sunlight to create the luminous haze that reflects Sunlight. They circle the Sun in the same plane as Earth.

So, look in the SW at least 90 minutes past Sunset. The bottom of it is as bright as the Milky Way is in the summer, and the upper part is dimmer since it is farther from the Sun. Some of what we will see is carbon, oxygen, silicon, iron, and magnesium that make up the shining debris. It is close to a pyramid shape.

Now that daylight savings time is here, the sky stays brighter and hour longer, and the morning sky stays dark an hour longer. Mercury is beginning to rise in the morning, but it is only 7 degrees high so we may not be able to see it with all our mountains. It was brightest on the 20th and 21st with the thin crescent moon close to it. They rose in the SE an hour before the Sun.

On the 18th the Moon, Mars and Jupiter formed a tight triangle in the morning. Saturn was just to the left of it. When Jupiter first rises it appears as bright as Venus and stays that way until it gets a little higher in the sky. Now that the morning sky is darker longer, you should be able to observe these planets.