The famous Eta Aquarid meteor shower – one of the year’s major meteor showers – peaks every year around May 5 and 6. This shower is known to be richer as seen from Earth’s Southern Hemisphere than from the Northern Hemisphere.
If you traced the paths of Eta Aquarid meteors backward on the sky’s dome, you’d find that these meteors appear to stream from an asterism, or recognizable pattern of stars, known as the Water Jar in the constellation Aquarius.
This spot in the sky is the radiant point of the Eta Aquarid meteor shower. The meteors seem to emanate from the vicinity of the Water Jar, before spreading out and appearing in all parts of the sky. Because the Water Jar is on the celestial equator – an imaginary line directly above the equator of the Earth – the radiant of the Eta Aquarid shower rises due east all over the world. Moreover, the radiant rises at about the same time worldwide, around 1:40 a.m. local time (2:40 a.m. daylight saving time) on or near May 5 and 6, the shower’s typical peak date. So you’d think the shower would be about the same as seen from around the globe. But it’s not. Why?
However, sunrise comes later to the Southern Hemisphere and earlier to the Northern Hemisphere during the month of May. For that reason, the radiant point of the Eta Aquarid shower climbs higher into the predawn sky at more southerly latitudes. That’s why the tropics and southern temperate latitudes tend to see more Eta Aquarid meteors than we do at mid-northern latitudes. Cruise to southerly latitudes, anyone?
