The almost-full waning gibbous moon is sure to obscure the 2015 Eta Aquarid meteor shower, which will probably produce the most meteors on Wednesday morning – May 6, 2015 – from about 3 a.m. until dawn. Our sky chart below shows the sky scene from mid-northern latitudes just before the onset of morning twilight. The Y-shaped “Water Jar” is the most prominent feature in the otherwise inconspicuous constellation Aquarius. Incidentally, this distinctive Y-shaped pattern of stars closely aligns with the radiant point of the Eta Aquarid shower. For more on the Eta Aquarid radiant and why more Eta Aquarids are visible from more southerly latitudes, click here.
In a dark sky, especially at more southerly latitudes, the Eta Aquarids can produce up to 20 to 40 meteors per hour. However, 2015 is not a particularly favorable year, as the waxing crescent moon will be shining mightily during the prime time hours of this meteor shower, in the dark hours before dawn. Meteor buffs will be on the lookout, despite the moonlit glare, knowing these swift-moving meteors frequently leave persistent trains.
This meteor shower favors the Southern Hemisphere, and the tropical and subtropical latitudes in the Northern Hemisphere. Appreciably north of 40 degrees north latitude (the latitude of Denver, Colorado), streaking meteors are few and far between. The early morning twilight at far northern latitudes washes these Eta Aquarid meteors from the sky. At this time of the year, morning twilight comes at a later hour to southerly latitudes.
Once again, the best viewing time is roughly from about two hours to one hour before sunrise. Unsure of your sunrise time? Or when nautical twilight begins? Check our almamac page. No matter where you live, the last hour of darkness just before dawn tends to feature the greatest number of meteors.
While you’re out watching the Eta Aquarids streaking the night, check out the planet Saturn and the star Antares near the moon.
Data gathered by the International Meteor Organization seems to suggest a possible connection between Jupiter’s 12-year orbit and the intensity of the Eta Aquarid meteors. Jupiter causes the Eta Aquarid meteor shower to put out a maximum number of meteors in 12-year periods, but to the best of our knowledge, astronomers aren’t expecting increased numbers of Eta Aquarid meteors in 2015.
Every year, as Earth passes through the orbital path of Comet Halley, bit and pieces shed by this comet burn up in the Earth’s atmosphere as Eta Aquarid meteors.