Equinoxes

• ‘Equinox’ means ‘equal nights’ meaning when Day and Night are both exactly 12 hours long everywhere on Earth, and occurs twice  a year.
• There are two points where the Ecliptic crosses the Celestial Equator each year, they are the Vernal Equinox and the Autumnal Equinox.

Description

• The Equinox occurs when the Sun is directly overhead the Equator.
• This happens twice a year at at midday on March 20th-21st and September 21st-22nd.
• These dates signify the beginning of Spring and Autumn in the Northern Hemisphere and the reverse in the Southern Hemisphere.

Vernal Equinox

• Vernal Equinox or Spring Equinox occurs on the 20th or 21st March when the Ecliptic crosses the Celestial Equator.
• In the Southern Hemisphere the Vernal Equinox occurs on September 22nd or 23rd.

Autumnal Equinox

• In the Northern Hemisphere the Autumnal Equinox occurs when the Sun crosses the celestial equator on September 22nd or 23rd.
• In the Southern Hemisphere the Autumnal Equinox occurs on March 20th or 21st