{"id":412,"date":"2011-09-11T00:00:31","date_gmt":"2011-09-11T00:00:31","guid":{"rendered":"http:\/\/www.skycaramba.com\/blog\/?p=412"},"modified":"2011-09-10T20:35:14","modified_gmt":"2011-09-10T20:35:14","slug":"the-dawn-before-the-dawn","status":"publish","type":"post","link":"https:\/\/www.skycaramba.com\/blog\/2011\/09\/11\/the-dawn-before-the-dawn\/","title":{"rendered":"The dawn before the dawn"},"content":{"rendered":"

SkyCaramba weekly astronomy blog for the week ending September 17, 2011<\/em><\/p>\n

If the skies are very dark where you live, you should try to see the dawn before the dawn. It\u2019s called the \u201cfalse dawn\u201d in the writings of one major religion. Sometimes, it appears in the evening as a twilight after twilight. Modern scientists call it the zodiacal light.<\/p>\n

For all we\u2019ve been told about the emptiness of space, there\u2019s actually a lot of stuff out there. Spacecraft must be built to be protected from penetration by pieces of space dust. Though small, they can cause considerable damage to something that runs into them at thousands of miles an hour. Little chunks of matter enter the earth\u2019s atmosphere all the time generating meteors. And when conditions are right, you can actually see the space dust reflecting sunlight out in space the way household dust accentuates the sunbeam shining between the curtains in a home.<\/p>\n

The zodiacal light is faint. It\u2019s so faint, a little moonlight or light pollution makes it impossible to see. The moon will make it a challenge this year. The September equinox is one of the best times to see the zodiacal light in the morning hours before sunrise. But a last quarter moon that week will shine in the morning sky. The good news is that the very next week, the moon will be new and no longer a threat to viewing.<\/p>\n

You\u2019ll probably see the first light of the real dawn one to two hours before sunrise. You can look for the zodiacal light two or three hours before that. It\u2019ll appear as a sort of triangular shaped area of light on the ecliptic. The ecliptic is the path the sun appears to take in the sky over the course of a year. That\u2019s not easy to visualize when the stars are out and the sun\u2019s not. It\u2019s easier around the times of the equinoxes though because the ecliptic is straight up and down from due east and west.<\/p>\n

So look up from the eastern horizon a few hours before the sun\u2019s up and try to find that patch of light. If you have a really dark site, you might see its peak way up high. If you\u2019re not sure you\u2019ve seen it, look up and around for the Milky Way stream. A common rule of thumb astronomers use is that if you can\u2019t see the Milky Way stream you won\u2019t see the zodiacal light. You could see the Milky Way stream and still have trouble spotting the zodiacal light though. The Milky Way will span from the southeast to the northwest that time of morning this time of year.<\/p>\n

Centuries ago, spotting the zodiacal light became important to Islam for the timing of some prayers. A believer would show more reverence to God by waiting until the real dawn to say a dawn prayer.<\/p>\n

If getting up earlier isn\u2019t your thing, you could wait for ideal conditions to see the zodiacal light in the spring. It\u2019s easier to see it in the evening then.<\/p>\n","protected":false},"excerpt":{"rendered":"

It’s called the “false dawn” in the writings of one major religion. But the phenomenon is real and explainable.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[200,198,199,201,197],"_links":{"self":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/412"}],"collection":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/comments?post=412"}],"version-history":[{"count":2,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/412\/revisions"}],"predecessor-version":[{"id":414,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/posts\/412\/revisions\/414"}],"wp:attachment":[{"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/media?parent=412"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/categories?post=412"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.skycaramba.com\/blog\/wp-json\/wp\/v2\/tags?post=412"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}