Autumn is the best time of year to see the false dawn, also known as the zodiacal light.
This light can be noticeable and easy to see from latitudes like those in the southern U.S. I’ve seen it many times from the latitude of southern Texas, sometimes while driving a lonely highway far from city lights, in the hour or so before true dawn begins to light the sky. In that case, the zodiacal light can resemble the lights of a city or town just over the horizon. Meanwhile, skywatchers in the northern U.S. or Canada sometimes say, wistfully, that they’ve never seen it.
You need a dark sky location to see the zodiacal light, someplace where city lights aren’t obscuring the natural lights in the sky. And you have to be up before dawn. If you don’t know when morning twilight begins in your sky, an astronomical almanac can tell you.
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Zodiacal light at Paranal. Credit: ESO/Y. Beletsky
What does it look like? The zodiacal light is a pyramid-shaped glow in the east before dawn. It’s even “milkier” in appearance than the starlit trail of the summer Milky Way. It’s most visible before dawn at this time of year because (as seen from the northern hemisphere) the ecliptic — or path of the sun, moon and planets — stands nearly straight up with respect to the eastern horizon before dawn now. At temperate latitudes in the southern hemisphere, where it is now spring, the zodiacal light is seen after dusk, rather than before dawn.
Image Credit: ESO/Y. Beletsky
The zodiacal light can be seen for up to an hour before true dawn begins to break. Unlike true dawn, though, there’s no rosy color to the zodiacal light. The reddish skies at dawn and dusk are caused by Earth’s atmosphere, and the zodiacal light originates far outside our atmosphere.
When you see the zodiacal light, whether it’s before dawn or after dusk, you are looking far beyond our atmosphere — edgewise into the space of our own solar system. The zodiacal light is actually sunlight reflecting off dust particles that move in the same plane as Earth and the other planets orbiting our sun.
Wow, what a fascinating article and beautiful pictures! I wish I could drive off the city lights and see something like that too!
OTOH, I knew this was gonna happen much sooner than later, lol… I climbed to the roof of my parents’ house once again to try and catch Mercury, just some five minutes earlier than yesterday and I finally did, even without binoculars… The thing is, the separation west-east from Venus is much larger than depicted where I checked… I’d say some 6-8 degrees as opposed to only some two degrees, so I just needed to look a bit earlier and far lower from Venus than I was looking yesterday… I even saw it set using my binoculars and yet again, I was dazzled by both Jupiter’s rising and Venus’ setting… I saw them exactly the same size, like one was the mirror image of the other! –Only Venus was flickering a bit right before setting while Jupiter was steady the whole time– and God, do they look incredible or what, I mean they are so big that they look like a couple of alien space shifts, one taking off and the other landing…
At the point where Mercury and Venus set today, lots of commercial planes were just taking off or landing because the airport is very near and believe me, none of their lights compared to Venus sie and brilliance even at a low altitude, except one just taking off whose lights faced directly to my binos and even dazzled me at a very low altitude, it looked like twice as brilliant as Venus, but that was the only one–
I know I seem crazy to go to the trouble of climbing to the roof and all, and even carrying the binos with me, but when I get there and see the beauty of the sky, it’s all well worth it! –besides I’m super-lucky that at the exact point where Venus and Mercury are setting these days, there are no obstructions like buildings or trees, so I see them set behind a short hill several miles away and that only adds to the beauty of the view!
i see the puritan in the blue room <3
Didn’t see anything like this on any night. Oh well, time for exercises with my co-workers…my neck is killing me! I still can’t do a handstand like she could, and even though I teased her for taking pictures of the grass, weird, she was always so nice to talk to about my brother with special needs.