At the moment of this year's March equinox, the sun was shining on two tropical cyclones in Australian waters and an impending supermoon.

Thanks to a coincidence of timing, this year's March equinox occurred within four hours of a supermoon.

The March equinox marks the moment our sun is positioned directly above Earth's equator, which makes day and night roughy equal in length around our planet.

Image: A satellite image taken within minutes of this year's March equinox.

The supermoon is a popularised term that refers to a new or full moon that occurs while the moon is near its closest point to Earth. Supermoons are slightly brighter and unpreceptively larger than 'normal' new or full moons.

This supermoon, which is the third of 2019, occurred at 12:43pm AEST, less than four hours after the March equinox at 8:58am AEST.

These two astronomical events happened while two tropical cyclones were spinning near northern Australia.

Between the equinox, supermoon and two tropical cyclones, there's a lot happening in the sky above Australia.

Nights will now be longer than days in Australia until the next equinox on September 23rd, 2019.