This weekend marks the peak of the Southern Delta Aquarids, a meteor shower that generally spans mid-July to mid-August, and reaches a maximum of about 20 meteors per hour. This year, the shower peaks today -- Saturday, July 28.

Observing the Southern Delta Aquarids

This year, the Southern Delta Aquarids coincides with the full moon, which makes viewing the shower a challenge. As with most astronomical events, the best strategy is to find an area well away from city lights, and away from streets where oncoming headlights could interfere with the view. City and state parks, or other secured areas, are the best bets. In the case of a meteor shower, such as the Aquarids, look in the direction of the constellation from which the shower radiates. In this case, that’s Aquarius, which rises in the southeast around midnight. Once you find a good vantage point, position yourself so that the horizon is at the edge of your peripheral vision and the sky fills your field of vision. This makes it easier to spot the meteors as they speed through the sky. It will be easiest to spot the shower in the half-hour or so between moonset and sunrise; by then, Aquarius will be high in the southwest.

History of the Southern Delta Aquarids

The origin of the Southern Delta Aquarids is something of an astronomical mystery. Meteor showers usually occur when Earth nears the path of the shower’s parent comet. If the comet passed by recently, the shower will be more intense than if the comet passed by long ago. In the case of the Southern Delta Aquarids, however, the parent comet is long gone, possibly knocked into a different orbit or destroyed by a collision. The shower, however, is still quite strong.

The first documentation of activity in the Delta Aquarid region was in 1870, and there were at least 20 other observances in the 19th century. In 1934, the first major study of the Southern Delta Aquarids were published, using observations made by the New Zealand Astronomical Society between 1926 and 1933. Though the Southern Delta Aquarids were studied extensively, the northern branch wasn’t officially discovered until 1950, and the southern branch is the more visual of the two.