Articles About Equinox (20)

March Equinox

At the March equinox, the Sun crosses the equator from south to north. Explanation and 2022 equinox date.

September Equinox

The Sun shines directly on the Equator on the September equinox and the length of day and night is nearly equal, but not quite.

When Does Spring Start?

The first day of spring is at the vernal equinox, when day and night are equal. Find out the exact time and date.

When Does Fall Start?

North of the equator, fall begins in September; in the Southern Hemisphere, it starts in March. Find out exact dates and how the fall season is defined.

The Earth in space, as seen by the crew of Apollo 11.

Equinoxes and Solstices

Equinoxes and solstices are a result of Earth’s tilt and its orbit around the Sun.

Full Moon Names

Full Moons had given names in many ancient cultures. The Full Moon names we use today often reflect nature like Harvest Moon.

2021/22 Cosmic Calendar

Celestial events and highlights of 2021 and 2022 including supermoons, solar and lunar eclipses, meteor showers, solstices, and equinoxes.

Tourists visiting the Papal Basilica of St. Peter in the Vatican City Rome, Italy - November 14, 2015

The Gregorian Calendar

The Gregorian calendar is the internationally accepted civil calendar that was first adopted in 1582.

A tree changing through the four seasons.

What Causes Seasons on Earth?

Seasons change because Earth's rotational axis tilts away or towards the Sun during the course of a year.

Bronze statue of Bolognese Pope Gregory XIII in Accursio Palace Bologna

Gregorian Calendar Reform: Why Are Some Dates Missing?

The Gregorian calendar was first introduced in 1582, however, different countries changed from the Julian Calendar at different times. Why were some days skipped?

Diagram showing the distance between the Sun and Earth at different times of the year (perihelion and aphelion).

Earth's Perihelion

Earth's closest approach to the Sun is two weeks after the December solstice is a coincidence and has no special significance.

Sun setting in the background with cloudy sky and trees in the foreground.

Equinox: Equal Day & Night?

Equinoxes don't have exactly 12 hours of day and night all over the world, like many believe. Such days, called equilux, do occur, but depend on your location.

Astronomy Glossary - Terms & definitions

Astronomical Glossary - Terms & Definitions

What do astronomers really mean when they use those technical terms?

Illustration showing Earth's axis drawn as a red line.

Earth Is Tilted

When an object the size of Mars crashed into the newly formed planet Earth around 4.5 billion years ago, it knocked it over and left it tilted at an angle.

A pathway in a park during fall (autumn).

10 Sept Equinox Facts

10 things you may not know about the September Equinox.

March: Worm Moon

The Full Moon in March is the Worm Moon. It is also called Lenten Moon, Crow Moon, Crust Moon, Chaste Moon, Sugar Moon, and Sap Moon.

March Equinox Facts

On Sat, March 20, 2022, day and night will be of almost equal duration in most time zones in the world.

June Solstice Traditions

In many Northern Hemisphere cultures, the June solstice is associated with holidays, feasts and celebrations.

September Equinox Customs

Folklore, customs, traditions and holidays surrounding the September equinox.

March Equinox Customs

Learn more about the customs, traditions and events surrounding the March equinox.