Earth in Space PH 464

1. How does the Earth move through space? 2 major ways: rotation and revolution

Rotation = the spinning of Earth on it’s axis 24 hours Day & night

Can you tell where the sun is? Do you know which side morning is on?

Revolution = the path Earth travels around the sun follows orbit one year

Calendar = system of organizing time that defines parts of a year

What causes the seasons on Earth? Earth’s axis is tilted as it revolves around the sun

Tilt = 23.5° Equator receives more direct sunlight. Poles receive less direct sunlight.

December 21 st = winter solstice = shortest day June 21 st = summer solstice = longest day

March 21 st = vernal equinox = “equal night” September 22 nd = autumnal equinox

2. What 2 factors combine to keep the moon and Earth in orbit? Inertia and gravity gravity = attracts all objects toward each other inertia = tendency of an object to resist a change in motion.

3. What determines how strong gravity is? Depends on the masses of the objects and the distance between them

First Lunar Olympics: With only 1/6th the gravity of Earth, you would have to divide your weight by 6 to see what you would weigh on the moon. On the moon most third graders would probably weigh between 8 and 15 pounds. Could you imagine what it would be like to play in the first lunar Olympics? Drawing by NASA-public domain image…

4. What are the results of the sun, moon, and the Earth’s position? The changing relative positions cause the phases of the moon, eclipses, and tides.

The Near Side of the Moon

The Far Side of the Moon

Neil Armstrong's First Photograph: This is the very first photograph that Neil Armstrong took after stepping off the Lunar Module footpad and becoming the first person to walk on the moon. NASA photo AS

Neil Armstrong After His Walk: That's one happy camper of a man. Neil Armstrong relaxes in the cramped Lunar Module after finishing his first walk on the moon. NASA photo as HR...

The dusty and rocky lunar landscape extends forever in this Apollo 17 photograph. In the distance is home and transportation back to Earth, the Lunar Module. NASA photo as Magnificent Desolation…

Crescent Moon, Crescent Venus

5. What determines the phase of the moon? How much of the sunlit side is facing the Earth Phase = different shapes of the moon

1. New Moon

2. Waxing crescent

3. 1 st Quarter

4. Waxing Gibbous

5. Full

6. Waning Gibbous

7. 3 rd Quarter

8. Waning Crescent

6. Does the moon produce its own light? No! It shines by reflected sunlight, not it’s own light

During what phases are the moon, Earth, and sun aligned in a straight line? A new moon and a full moon

Would Earth ever appear to set below the horizon for someone standing next to the flag on the moon? NO! Earth would not appear to set because that point on the moon’s surface is always facing Earth.

7. What is a solar eclipse and how does it happen? When the moon passes directly between Earth and the sun, casting a shadow on the Earth

What is the difference between the umbra and the penumbra? Umbra is the darkest part of the shadow, the penumbra is the larger, less dark part of the shadow

8. What is a lunar eclipse & how does it happen? Earth blocks sunlight from reaching the moon.

During which phase of the moon can lunar eclipses occur? Full moon!

9. What are tides? The rise and fall of ocean water every 12.5 hours.

10. What causes tides? Differences in how much the moon’s (and sun’s) gravity pulls on different parts of Earth

When do spring tides occur? Occur when Earth, Moon and Sun are aligned in a straight line During a new and full moon

Spring Tides

What is a neap tide? When the moon is at a right angle to the sun. During a 1 st and 3 rd quarter

Neap Tides