Sun, Earth , and Moon

People (Ptolemy in 140 A.D) once thought that Earth was at the center of the Universe and the Sun revolved around it.

Geocentric Theory

Copernicus in 1530 created a mathematical model which explained the motions of the planets by putting the Sun in the center of the solar system, his book was suppressed for 13 years. When the it was finally published, Copernicus was on his deathbed,

Heliocentric Theory

SphericalThere was the belief that Earth was flat. Aristotle who lived in 350 BC thought that Earth was spherical. He saw Earth cast a shadow on the Moon during an eclipse. Sailors also

saw evidence that the Earth is spherical from observing how ships appear in the horizon. They also saw that when moving North or South the North star moved higher or

lower in the sky. Earth is Spherical and bulges slightly at the equator and

somewhat flattened at the poles

Earth’s Rotation: The spinning of Earth on it’s axis, causes day and night. 24 h

Earth’s Revolution: 365 days Diameter (Pole to Pole): 12,714 km Diameter (equator): 12,756 km Average Distance from the Sun: 150 million km

*Label the diagram of Earth*

Physical Features

Generated by movement of materials inside Earth’s core and Earth’s rotation. Earth has a North and South Magnetic pole. It traps many charged particles from the sun which protects you from harmful solar radiation. }

Magnetic Field

1. Caused by Earth’s Revolution around the Sun. Due to the ellipse shape of Earth’s orbit around the Sun the distance from the Sun to Earth changes during it’s yearlong orbit. It is closest (147 million km ) around Jan 3 and farthest (152 million km ) July 4.

2.The tilt in Earth’s axis causes seasons. The hemisphere that is tilted more towards the Sun will be in summer and that which is tilted away will be in winter.

It also affects the number of daylight hours. For example the summer has longer sunlight hours than the winter. * Complete compare and contrast table summer/winter*

Seasons

The day when the Sun reaches its greatest distance north or south of the equator.

Northern: June 21 or 22 longest period of daylight

Southern: Dec 21 or 22 shortest period of daylight

Solstices

when the Sun is directly above Earth’s equator. Occurs twice a year when the sun is directly over the equator (90 ° angle) resulting in spring and fall equinox. The number of daylight and night time hours and equal all over the world. Neither hemisphere is tilted toward the Sun.

Equinoxes

Northern hemisphere: spring equinox March 20 0r 21 Fall equinox Sept 22 or 23 Southern hemisphere: spring equinox Sept 22 or 23 Fall equinox

March 20 0r 21 *Do Venn Diagram Solstices & Equinoxes & Connect It *

Revolution around Earth are responsible for the changes in it’s appearance. 27.3 days the same amount of time it takes to revolve around Earth.

The Moon revolves around Earth you see different portions of its lighted side, causing the Moon’s appearance to change.

Moon Motions

The different forms that the Moon takes in its appearance from Earth. 29.5 days

New Moon: when the moon is between Earth and the Sun. The lighted half is facing the Sun.

Waxing: More of the illuminated half of the Moon can be seen each night. Waxing crescent, first quarter, gibbous

Phases

Full Moon: all of the Moon’s surface facing Earth reflects light

Waning: When you see less of its illuminated half each night. Gibbous, third quarter, Waning crescent

* Complete cut & past Moon Phase Activity *

Phases

The revolution of the Moon causes eclipses. It occurs when Earth or Moon blocks the sunlight from reaching the other.

New Moon: the Moon’s shadow falls on Earth and causes a solar eclipse. ( pearly white glow seen in a total solar eclipse .. umbra)

Full Moon: Earth’s shadow can be cast on the Moon, resulting in a lunar eclipse. ( Total Lunar eclipse can be seen by anyone on the night time of Earth)

Eclipses

Craters: depressions due to Meteorites, asteroids, comets striking the surface.

Maria: dark regions formed from igneous rocks.

The moon has a crust, mantle , and a core

Moon

Theories of formation 1. The moon was captured by Earth’s gravity 2. The moon condensed from the same dust

and gas. 3. Earth ejected molten material that

became the Moon.

Moon’s gravity Is 1/6 of Earth’s

Moon

4. Impact theory: after Apollo space missions in 1960’s and 1970’s The moon formed billions of years ago from condensing gas and debris thrown off when Earth collided with a Mars-sized object.

Impact theory

1961 The US sent the first ranger spacecraft and a series of Lunar Orbiters to the moon. They took photographs of the Moon. The next step they landed on the moon.

1969: Apollo 11 landed on the Moon.

Exploring

Clementine: 1994 was placed into lunar orbit to conduct a two-month survey of the Moon’s surface.

It took high resolution photographs of the Moon’s surface.

Lunar Prospector: 1998 spent a year orbiting the Moon from Pole to pole.

Exploring

Lunar Prospector also Mapped Moon’s gravity, magnetic field, and the abundances of 11 elements in the crust.

Evidence confirmed that water ice was present in deep craters at both lunar poles.

Icy Poles