Autumn begins on the equinox, the day the Sun crosses the equator. The earliest known civilizations celebrated the equinoxes, and they're still celebrated in many places. One of the biggest autumn celebrations is the Chinese Moon Festival. A traditional Chinese garden has a moon-watching pavilion.Autumn Equinox
Equinoxes in many places are festival days. But astronomically speaking, an equinox happens at a specific time. The September 2020 equinox occurred when the Sun crossed the celestial equator from north to south. This happened yesterday (September 22) at 13:30 UTC (Coordinated Universal Time), which is essentially GMT (Greenwich Mean Time).
The time the equinox occurred in your location depends on your time zone. For people in Britain, this was 14:30 BST (British Summer Time) - 2:30 pm. In western Europe, it was 15:30, in New York, 9:30 am, and in California 6:30 am.
In Melbourne, Australia the time of the equinox was 11:30 pm and in New Zealand it was 1:30 am on September 23. And in the whole southern hemisphere it was the spring equinox.
For people living outside the tropics, June 21st is the longest or shortest day of the year, a solstice. It marks the first day of summer in the northern hemisphere and winter in the southern hemisphere. But why do we have seasons? And do other planets have them?Why Planets Have Seasons
Autumn equinox and autumn sky, discoveries and discoverers, an ancient festival that marked the transition from the light to darkness. Can you identify them?Autumn Equinox to Halloween – Quiz