Earth Revolves Around the Sun Earths Revolution Earth

Earth Revolves Around the Sun

Earth’s Revolution • Earth revolves around the sun in an elliptical orbit or path once a year • It takes Earth 365. 25 days to revolve 360° in its orbit around the sun.

The tilt of the axis always stays the same!

Evidence of Earth’s Revolution around the Sun • Seasonal Constellations: Because of the Sun’s annual motion, some constellations are visible at night only during certain seasons. • Constellations are visible when the dark side of Earth (away from sun) faces toward the constellation – at night!.

The 13 constellations the sun appears to travel through during the year

Different constellations at different times of the year

Apparent Motion of Sun due to Earth’s Revolution • However, the path the sun appears to take across the sky changes both its position and its length with the seasons

Summer maximum altitude of noon sun is 73°, Winter is 26° Spring/Autumn?

Earth’s Revolution around the Sun – the tilt of Earth’s axis does not change. This creates the seasons.

How can a tilt create seasons?

It’s all about the angle at which the sun’s light hits the Earth.

Is the light DIRECT or INDIRECT?

Review: • How does each of these prove the Earth revolves around the sun? – The changing constellations in the sky? – The path the sun takes as it crosses the sky each day? – The seasons?