This year began with the prediction that 2013 could be "The Year of the Comet." In March, we watched for C2011 L4 Comet Pan-STARRS to appear as the colors of sunset gave way to dusk, then enjoyed photographs of the star-with-a-tail captured by skilled astro-photographers and hobbyists alike. In our imaginations, a great boulder of ice and cosmic dust took shape, hurtling from the edge of our solar system and passing by Earth on its trajectory toward the sun and back.
Scarcely two weeks ago, our planet, spinning and speeding through the cosmos as it orbits our star, moved through the remnants of an ancient comet, C1861 G1 Comet Thatcher, that gave us the Lyrid meteor shower. The debris stream of a comet consists of meteoroids, tiny to meter-sized rock and icy fragments. Upon entering Earth's atmosphere at great speed they heat to incandescence and are known as meteors or shooting stars. A meteorite is what is left of a meteoroid or an asteroid that survives its blazing fall through Earth's atmosphere, as was observed recently in Russia.
The Lyrids overlap the first days of the Eta Aquarid meteor shower that is active between April 19 and May 20.
We are now traversing the orbit of historied 1P Halley's Comet that swung by Earth in 1989 and will return in 2061. The Eta Aquarids peak before dawn each day from tomorrow through Monday, with an emphasis on Monday.
The radiant of the Eta Aquarids is a dim star by that name that will be above the eastern horizon to the left of the crescent moon tomorrow before dawn and above the moon on Sunday.
The waning crescent rises at 3:47 a.m. Monday, so it may not be visible during the ideal time to be observing, around 4 a.m. Look low in the east and everywhere for meteors in the pre-dawn sky.
Comet ISON update coming soon.
To contact Judy Isacoff, go to www.naturesturn.org