What Is The Zodiacal Light? Keep A Lookout for The Celestial Phenomenon This Month
February may not have any meteor showers to dazzle us Earthlings, but that doesn't mean you should hang up your binoculars until next month. According to astronomers, it's almost the perfect time of year to catch the "zodiacal light" phenomenon illuminating the western horizon. If you've never heard of the zodiacal light before, it's understandable; it's notoriously difficult to observe, especially given the amount of planetside light pollution drowning out its faint glow. If you manage to find dark skies and an unobstructed view of the horizon, though, it's worth the effort.
According to Space.com, the zodiacal light is a cone-shaped glow created from sunlight reflecting off of millions of dust particles floating around the galaxy. Its name comes from its location in the sky: It's located along the same plane as the band of 12 constellations known as the zodiac. (Yep, these are the same constellations used to make predictions about the future in astrology.) These days, astronomers prefer to use the term "ecliptic," a reference to the path of the Sun and the Moon, instead of "zodiac"; they also include the (sometimes controversial) constellation Ophiuchus in their calculations. The term "zodiacal light," however, has stuck around despite the changes.
According to EarthSky.org, the best time to view the ghostly light is before dawn in the fall and just after nightfall in the spring, so viewing season is coming up. On Wednesday, NASA's Jet Propulsion Laboratory released a video explaining notable skywatching events for February, including zodiacal light near the end of the month and extending into March.
So how do you catch the zodiacal light? Its glow is even fainter than the Milky Way, so first, and most importantly, get as far away from sources of light pollution. That includes the moon, which will be waning until the new moon on Feb. 25. According to EarthSky, the best time to catch the zodiacal light in the spring is right after night has fallen, because that's when the ecliptic is most perpendicular to the Earth.
As Space.com points out, human eyes need about 20 minutes to totally adjust to the darkness. Once your eyes are as sensitive as they're going to get, look for the zodiacal light on the western horizon. NASA recommends using Venus and Mars, both of which can be seen with the naked eye, to guide your eye toward the glow.
If you don't manage to spot the zodiacal light, don't get too frustrated. It's known for being difficult to find. Either way, lay back and enjoy the starry skies — maybe you'll spot the equally lovely Milky Way instead.