Debris from the creation of the planets more than 4.5 billion years ago is present throughout the Solar System. The orbits of some of this debris, including comets and asteroids, intersect Earth’s path around the Sun. These comets and asteroids leave behind debris every time they swing in the direction of the Sun. Their orbits get obscured by wide streams of dust over the course of hundreds or thousands of years.
The yearly meteor showers are the result of the Earth’s continuous passage through these streams of debris as it orbits the Sun. We return to the same location in our orbit every year, run into the same stream of junk, and enjoy another beautiful display as the trash burns up 80 kilometres overhead harmlessly. The Earth is travelling through a region of space where three streams of debris cross our planet’s orbit in the middle of Australia’s winter. The Piscis Austrinids, the Alpha Capricornids, and the Southern Delta Aquariids are the three streams that give rise to this Weekend main performers.
The Southern Delta Aquariid and Alpha Capricornid meteor showers include 3D animated visuals from the International Meteor Organization that demonstrate how the space debris is dispersed. Of the three showers, the Southern Delta Aquariids is the most active and produces the meteors that move the quickest. This stream is expected to include the majority of the meteors you see this Weekend.
There is substantial disagreement over the Southern Delta Aquariids’ origin. They are one of several meteor showers that appear to be connected to a single parent object, as though a gigantic comet broke up long ago and left behind a massive quantity of debris, maybe even pieces big enough to constitute comets in their own right.