Earth Orbit Calendar
Chapter 1

The illusion of a stationary Earth

Chapter 2

The sun takes center stage

Chapter 3

The math of a year

Chapter 4

Solving the calendar puzzle

YOUR GOAL

Master of How we found our place in space

Ch 3 · The math of a year
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Spinning the Year
BETA

futura Spin Earth around the Sun to discover how we created the calendar year.

Aug 16

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futura Earth Orbit Calendar

The Earth spins 'round the Sun, you see, (Oh-oh, not perfectly!) Five hours and forty-eight more, (Yeah-yeah, that's what calendars are for!)

Aug 16

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futura Solstices and the tilt of Earth

Aug 16

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Equinoxes and equal days

futura Twice a year, the Earth's tilt aligns perfectly with the Sun, producing equal day and night worldwide.

Aug 16

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Solstices and the tilt of Earth

futura Earth's axial tilt of 23.5 degrees causes the changing seasons and the extreme days of the solstices.

Aug 16

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Fun Fact

Earth's speeding orbit: Earth travels around the Sun at a blistering speed of about 67,000 miles per hour.

Aug 16

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Glossary
leap year (noun)
A calendar year containing an extra day to keep it synchronized with the astronomical or seasonal year. Julius Caesar implemented this quadrennial correction in 45 BC to stabilize the Roman calendar.

Aug 16

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Gossip

Which season is the best?

Aug 16

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Quiz

What is the precise length of a tropical solar year on Earth?

Aug 16

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futura Equinoxes and equal days

Aug 16

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Quiz

At what angle is the Earth's rotational axis tilted relative to its orbital plane?

Aug 16

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futura The exact length of a year

Aug 16

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Quiz

What is the primary cause of the changing seasons on Earth?

Aug 16

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futura Earth's varying orbital speed

Aug 16

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Quiz

What is the term for the point in Earth's orbit where it is closest to the Sun?

Aug 16

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Quiz

At approximately what speed does the Earth travel as it orbits around the Sun?

Aug 16

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Quiz

What does the word solstice literally mean in Latin?

Aug 16

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Quiz

During which month does the Earth reach aphelion, its farthest point from the Sun?

Aug 16

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Quiz

What does the word equinox literally translate to in Latin?

Aug 16