Chapter 20 lesson 1

Chapter 20 lesson 1

Earths Motion

Poll

EARTHS MOVEMENT AROUND THE SUN CAUSES SUNRISES AND SUNSETS?

• AGREE

• DISAGREE

Poll

EARTH HAS SEASONS BECAUSE ITS DISTANCE FROM THE SUN CHANGES THROUGHOUT THE YEAR.

• AGREE

• DISAGREE

How does earth move?

https://www.youtube.com/watch?v=I_gT_EPQtd4

The Sun

• Suns diameter more than 100 times greater than earths

• Nuclei of atoms combine in the sun making huge amounts of energy- Fusion

• Thermal energy and light

Multiple Choice

How hot is our suns core?

• 5,500 deg C

• 15,000,000 deg C

• 15,000 deg C

• 5,00,000 deg C

Earths Orbit

• Orbit-path object follows as it moves around another object

• Revolution- Motion of one object around another object

Multiple Choice

How long does it take for earth to make one complete revolution around the sun?

• 1 day

• 1 year

• 1 month

• 1 week

Sun and Earth

• Earth moves around sun because of pull of gravity between them

• Gravity depends on masses of objects, and distance between them

Multiple Choice

Whats us known as the spinning motion of an object?

• Rotation

• Revolution

• Orbit

• Elliptical

Earths Rotation

• Rotation axis- Line on which an object rotates

• Earth rotates in counterclockwise direction, from west to east

• Earths complete roation is 24 hours

• Earth rotates from west to east, making the sun appear to move east to west

• Axis either pointed toward or away from sun

Temperature and Latitude

• Sun shines on part of earth that faces sun

• When light shines on a tilted surface, the light is more spread out than it would be on a surface that is not tilted

• Earth surface becomes more tilted moving away from the equator

• Warmer at equator, colder at poles, less energy

Multiple Choice

What causes seasons?

• Earths distance from the sun

• Earth closest to sun, summer

  Earth further from sun, winter

• The tilt of earths rotation axis, and earths motion around sun

• Suns gravitational pull

Seasons

• End of earths axis the points toward the sun gets more energy. Temps are higher

• Part of earth tilted toward sun experiences spring and summer (warmer, longer days)

• Part of earth tilted away from sun experiences autumn and winter (cooler, shorter days)

Multiple Choice

If the northern end of Earth’s axis leans toward the Sun, it is spring or summer in which hemisphere?

• Northern

• West

• East

• Southern

Multiple Choice

If the southern end of Earth’s axis leans toward the Sun, it is fall or winter in which hemisphere?

• Northern

• Southern

• East

• West

Solstices

• Solstice- Day when earths axis is most towards or away from sun

• December solstice: North end of axis away from sun, days shortest, nights longest in northern hemisphere. Winter begins

• June solstice: North end of axis toward sun, days longest, nights shortest in northern hemisphere. Summer begins

• Oppostie for southern hemisphere

Equinoxes

• Equinox- Earths axis is leaning along earths orbit, neither toward nor away from sun

• September: 12 hours of day, 12 hours of night. Autumn begins in north, spring begins in south

• March: same as spring, but Autumn begins in south, and spring begins in north