GREETINGS, SEASON

Autumn season 2020: What is the equinox and what happens on the first day of autumn?

TODAY is Earth's autumn equinox.

This means the start of autumn with cooler shorter days for the Northern Hemisphere and there's some scientific reasons behind it.

What is the autumn equinox?

The autumn equinox is the day when daylight hours and night time are of equal length.

It marks the day when the Northern Hemisphere slightly tilts away from the Sun, meaning days become shorter and the temperature begins to cool.

This carries on until the winter solstice when the Northern Hemisphere begins to tip back towards the sun on its axis.

The autumn equinox this year falls on September 22 (TODAY).

This means it's about to get colder for 90 per cent of Earth's population but warmer for those living in the Southern Hemisphere.

Equinoxes, just like solstices, happen because of how the Earth is titled relative to the Sun.

The Earth spins on an axis that's tilted at about 23.5 degrees.

Because of this tilt, as the Earth makes its way around the Sun each year, different parts of it get exposed to more or less sunlight.

This is why we have seasons.

The most dramatic changes occur during the summer and winter solstices.

However, during the autumn and spring equinoxes, the Earth's tilt means it's perpendicular to the Sun's rays and they hit it evenly.

That means both sides of the Earth receive exactly 12 hours of day and night.

This only happens twice a year and it's happening for the second time in 2020 on September 22.

Some plans have had to be cancelled this year...

For people missing summer, autumn coincides with a number of annual celebrations and events - but coronavirus has already taken an axe to some.

Oktoberfest in Germany, for example - billed as the biggest beer festival in the world - was already canceled in April.

Halloween, which falls on October 31 every year, may also have to be scaled back at the very least.

In the US, their traditional Thanksgiving holiday in November may be difficult to carry out as normal if social distancing orders remain in place.

For those in the UK, socially-distanced fireworks on Bonfire Night on November 5 should be more than possible.