Image Credit & Copyright: Yuri Beletsky.
Where do we even begin here? When you’re one of the most prolific night sky imagers out there, it’s hard to meet the bar you have raised for yourself time and time again but this image really goes the distance in my humble opinion. Imaged by Yuri Beletsky, we see the incredible night sky far away and long ago, high above the extinct volcano, Rano Kau on the legendary Easter Island. That same sky, reflected in the waters of the crater lake.
WHAT IS IT?
As awe inspiring as this image is, who knows what we’re looking at here? I’m not talking about the Milky Way, but instead that tall pillar of light, seemingly rising from the volcano as if its spirit has been awakened to communicate with the universe. Twice a year the orientation of the Earth places us at a prime vantage point to view a little known, hard to see, and in my opinion underappreciated phenomenon. Known to the ancient Persian as well as Arabic astronomers as “False Dawn” (in the fall months) or “Tall Twilight”, Zodiacal light is a vast towering pyramid of light whose point follows the zodiac constellations (thus the name) and Ecliptic into the night sky, reaching out for the Milky Way, kind of beautiful and spooky right?
In short, Zodiacal light is a vast dust ring that lies in the inner solar system. It’s believed that it reaches out past the orbit of Mars into the main asteroid belt. As the Sun sets in the west or rises in the east (depending on what time of year) its glare scatters light of billions of those microscopic dust particles, putting on a show for those wise enough to successfully hunt it. Those billions of interplanetary dust particles, too small for any telescope to resolve, pancake out along the plane of the ecliptic just as the planets and asteroid belts do. To this day astronomers are not 100% certain as to the complete picture but it’s believed that the Main Asteroid Belt contributed to approximately 10% of the particles mass, which in total is only about the same mass as Mars Moon, Phobos. Most of the dust, it is believed, comes from the blown off leftovers of Short Period Comets as well as material that created the solar system itself, 4.5 billion years ago.
HOW TO SEE IT FOR YOURSELF
The two best “seasons” or times of year to view Zodiacal Light are roughly March/April and again in September/October (Surrounding the equinoxes). You can still spot them during some of the surrounding months as well but it’s tougher the further you get from the equinox as those are the two key times of the year when the ecliptic is highest in the sky. Another note here is that the closer to the equator you are the easier it will be to view because of the location and orientation of the ecliptic as well. The further you venture from the equator the more difficult it becomes to catch because of that angle.
This being the March/April season, you will need to get to the darkest skies you can find that have an open, clear western horizon and begin watching an hour after sunset and just following twilight. The pillar of light should be near vertical and if there are any evening planets find them because they will be in the thick of it.
Also, by dark that means the Moon as well, so shoot for New Moon weeks or weeks when the Moon is opposite that particular twilight. In this case, new and old last quarter moons will be fine because they don’t rise until morning. If you can’t see the Milky Way overhead it isn’t dark enough. Your DSLR will pick up the light much better than your eyes, but that being said, it will also pick up the glow of the surrounding towns which may wash the Zodiacal Light out so just like aurora hunting. Not just in the sky but on the horizon in in the direction that you’re looking as well. Dark is mandatory!
The September/October season means that prime viewing is in the east an hour before sunrise and just before twilight when the ecliptic is closest to vertical. All the same dark sky junk still applies of course.
For my SOUTHERN HEMISPHERE friends, everything is opposite. September/October you will need a western view an hour after sunset and after twilight. In the March/April season prime viewing will be an eastern view an hour before sunrise and before twilight.
All in all, just get out there and give it a shot. Also, don’t take everything written here as a 100% must-follow either; many amazing photos have come from months surrounding peak months. Use this as a guideline and see what your night sky is telling you personally!
The World At Night (TWAN) page for this image: http://spaceweathergallery.com/indiv_upload.php?upload_id=119930
Yuri’s Facebook: https://www.facebook.com/yuribeletskyphoto