THE PLANET EARTH Science 1º ESO – Unit 2 © I.E.S. “Luis de Góngora” (Córdoba); Dept. Biology and Geology Juan Manuel Barroso Fernández Bilingual Educational Project.

We are about to start a trip through the Milky Way, looking for the Earth!

Photo: cosmos4kids.com

Planet Earth Sun

This is our planet, the EARTH Earth is the third planet in our Solar System That, in turn, is located in the galaxy “Milky Way” The Earth is 12,756 km in diameter It is 1.5 million km from the Sun Photo of the Earth: cnice

THE EARTH’S MOTIONS Earth rotation: The Earth moves in two different ways: It spins around its own axis every 24 hours Earth rotation Earth revolution The spinning gives rise to night and day Photo of the Earth: cnice

THE EARTH’S MOTIONS Earth revolution: It occurs on a plane called the “ecliptic plane” It revolves around the Sun, each revolution having a period of a year. The rotation axis has an angle of 23.5 degrees in relation to the perpendicular axis of the ecliptic plane. Its orbit has an elliptical shape and the Sun is placed in one of the two focuses. 23.5º Photo of the Earth: cnice

SEASONS In our hemisphere each season starts on… As a consequence of revolution and this inclination, the Earth has seasons. Spring Equinox: 21st March Winter Solstice: 22nd December Summer Solstice: 21st June Autumn Equinox: 22nd September Photo of the Earth: cnice

OUR PLANET HAS FOUR LAYERS… It is the rocky part of the Earth It is the aqueous layer. It’s made up of liquid and solid water It is the gaseous layer that surrounds the Earth. Its made up of air ATMOSPHERE It is all living things HYDROSPHERE BIOSPHERE GEOSPHERE Photo of the Earth: cnice

CRUST UPPER MANTLE LOWER MANTLE OUTER CORE INNER CORE The crust is the first rocky layer. It’s made up of granite and basalt The core is the deepest layer. It’s made up of iron The mantle is located below the crust, between 35 and 2,900 km Photo of the Earth: cnice

The Moon is the Earth’s Satellite The Moon is the only satellite of the Earth. Main Characteristics It is 3,760 km in diameter It is located 384,400 km from the Earth Photo of the Moon: cnice

The moon is always addressing us with the SAME FACE The Moon’s Motions It has TWO different movements: 1. ROTATION: with a 28-day period 2. REVOLUTION: also with a 28-day period As a consequence of these synchronized movements… The moon is always addressing us with the SAME FACE Photo of the Moon: cnice

The Moon seen from Earth: Seen from Earth, the Moon’s look varies according to its position in the orbit… Photo of the Moon: cnice

This way, LUNAR PHASES are distinguished: The Moon seen from Earth: This way, LUNAR PHASES are distinguished: THIRD QUARTER Moon NEW Moon FULL Moon FIRST QUARTER Moon

ECLIPSES An eclipse occurs when the Earth, the Moon and the Sun form a line: If the Moon comes into the Earth’s shade, a lunar eclipse takes place. If the Earth comes into the Moon’s shade, a solar eclipse takes place.

SOLAR ECLIPSE A solar eclipse occurs when the Moon is in the middle. This means that the Moon has to be a New Moon. NEW Moon

LUNAR ECLIPSE A lunar eclipse occurs when the Earth is in the middle. This means that the Moon has to be a Full Moon. FULL Moon

Why aren’t there eclipses every month? NEW Moon FULL Moon

This is the ecliptic plane (where the Earth revolves around the Sun) 5º However, the Moon revolves around the Earth on a plane that forms a 5º angle with this plane… … This is why we only can get an ECLIPSE: - When the Moon is on the ecliptic plane - And, at the same time, the Earth, the Moon and the Sun form a line.

A LUNAR ECLIPSE occurs. A SOLAR ECLIPSE occurs. If the EARTH is in the middle… If the MOON is in the middle… A LUNAR ECLIPSE occurs. A SOLAR ECLIPSE occurs.

The Moon is between the Earth and the Sun (NEW Moon) The MOON is on the ECLIPTIC PLANE Ecliptic plane A SOLAR ECLIPSE occurs.

The Earth is between the Moon and the Sun (FULL Moon) The MOON is on the ECLIPTIC PLANE Ecliptic plane A LUNAR ECLIPSE occurs.

Although the Moon is located on the ecliptic plane… The SUN, the EARTH and the MOON DO NOT FORM A LINE Ecliptic plane There IS NOT an ECLIPSE

Although the Moon is located BETWEEN The Earth and the Sun, a New Moon… …or it is a Full Moon… …The Moon IS NOT on the ECLIPTIC PLANE There IS NOT an ECLIPSE