This imaginary sphere is called the Celestial Sphere. For 2021, the autumnal equinox occurs on the 20th March 2021 at 5:37pm, and the vernal equinox occurs on the 23rd September 2021 at 3:20am.īy the way, the Celestial Equator is just a projection of Earth’s equator onto the imaginary sphere that we picture surrounding our planet when we look up at the night sky. On the dates of the equinox, the Sun is exactly above the Earth’s equator, causing the equal length of night and day. The autumnal equinox occurs around March 21, and the vernal equinox occurs around September 23 each year. These dates are known as equinoxes, and there are two a year. This means there has to be a ‘tipping point’ where hours of daylight are just about the same as the hours of night. Hours of daylight are greater in summer and less in winter. This axial discrepancy leads to changes in the amount of daylight any given place on the Earth receives. For example the Southern Hemisphere is angled towards the Sun during summer and away from it in winter. Our Earth is quite laid back, about 23.5 degrees! The axis of rotation of our Earth is roughly 23.5 degrees, meaning that as the Earth orbits the Sun, the angle a point on the surface makes with the Sun varies. Vernal means new or fresh, and the Latin roots of equinox refer to the near-equal length of day and. The Earth’s axis isn’t tilted toward the Sun one way or the other and the hours of night and day are almost equal in length. The spring equinox is also known as the vernal equinox. It is an event that indicates the start of spring, so we can look forward to the warm months. This is when the centre of our Sun is on exactly the same plane as Earth’s equator. The spring equinox usually falls around the 21st March each year. Equinoxes happen twice a year when our Sun crosses Earth’s Celestial Equator.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |