EARTH SCIENCE: AN INTRODUCTION

What is Earth Science? the study of the Earth and its neighbors in space.

The Four Earth Sciences Geology Meteorology Astronomy Oceanography

Geology: Science of the Earth deals with the composition of Earth materials, Earth structures, and Earth processes

Meteorology: Science of the Atmosphere study of the atmosphere and how processes in the atmosphere determines Earth’s weather and climate

Astronomy: Science of the Universe study of the universe and the heavenly bodies

Oceanography: Science of the Oceans study of the Earth’s oceans—their composition, movement, organisms and processes

Importance of Studying Earth Science an understanding of the rocks and minerals that make up the solid Earth, and how these materials interact with atmosphere, the world water supply, and living organisms provides the foundation for all natural and environmental sciences.

Importance of Studying Earth Science can lead to discovery of sources of energy, mineral resources and fresh water.

Importance of Studying Earth Science understanding the dynamic structure of the Earth’s crust and interior helps us to predict and avoid natural hazards.

Importance of Studying Earth Science studying the rock record gives us insight into past environmental changes, from which we may able to make predictions about how the Earth could change in the future.

THE SOLAR SYSTEM

What Is The Solar System? The Solar System is made up of all the planets that orbit our Sun. In addition to planets, the Solar System also consists of moons, comets, asteroids, minor planets, dust and gas.

The Solar System Everything in the Solar System orbits or revolves around the Sun. The Sun contains around 98% of all the material in the Solar System. The larger an object is, the more gravity it has. Because the Sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it.

Satellite any such object in space that moves in a definite orbit around a larger body. Earth is a satellite of the sun, revolving at a speed of about 66, 600 miles per hour.

If collisions occur? Yes, the earth collides with thousands of small members of the solar system everyday.

How did the Solar System form?

Formation of the Solar System Theories Planetisimal theory Nebular theory

Planetisimal Theory According to the planetesimal theory developed by T. C. Chamberlin and F. R. Moulton in the early part of the 20th cent., a star passed close to the sun. Huge tides were raised on the surface; some of this erupted matter was torn free and, by a cross-pull from the star, was thrust into elliptical orbits around the sun. The smaller masses quickly cooled to become solid bodies, called planetesimals. As their orbits crossed, the larger bodies grew by absorbing the planetesimals, thus becoming planets.

Nebular Theory developed by Immanuel Kant and given scientific form by P. S. Laplace at the end of the 18th cent., assumed that the solar system in its first state was a nebula, a hot, slowly rotating mass of rarefied matter, which gradually cooled and contracted, the rotation becoming more rapid, in turn giving the nebula a flattened, disklike shape. In time, rings of gaseous matter became separated from the outer part of the disk, until the diminished nebula at the center was surrounded by a series of rings. Out of the material of each ring a great ball was formed, which by shrinking eventually became a planet. The mass at the center of the system condensed to form the sun.

THE SUN

The Sun The Sun is actually a large star. Because the Sun is closer to us than any other star, it appears as a ball of orange, yellow, or white light in the sky. Like most stars, the Sun is a large mass of hydrogen and helium gases that constantly “burn” and re-generate, giving off heat energy and light.

Layers of the Sun The inner layers are the Core, Radiative Zone and Convection Zone. The outer layers are the Photosphere, the Chromosphere, and the Corona

Layers of the Sun Core- source of all the Sun's energy - has a very high temperature, more than 15 million degrees Kelvin, and the material in the core is very tightly packed or dense.

Layers of the Sun Radiation zone- the region surrounding the core of the Sun.

- Throughout this region of the solar interior, energy, in the form of radiation, is transferred by its interaction with the surrounding atoms.

- The temperature is a little cooler than the core and as a result some atoms are able to remain intact.

Layers of the Sun Convection zone- Energy continues to move toward the surface through convection currents of the heated and cooled gas.

Layers of the Sun Photosphere- the deepest layer of the Sun that we can observe directly.

- It reaches from the surface visible at the center of the solar disk to about 250 miles (400 km) above that.

Layers of the Sun Chromosphere- an irregular layer above the photosphere where the temperature rises from 6000°C to about 20,000°C. At these higher temperatures hydrogen emits light that gives off a reddish color.

Layers of the Sun Corona- outermost layer of the Sun, starting at about 1300 miles (2100 km) above the solar surface (the photosphere).

- The corona cannot be seen with the naked eye except during a total solar eclipse, or with the use of a coronagraph.

Solar Activities Sunspots Prominences Solar flares

Sunspots dark, irregular patches of the photosphere gigantic areas of the solar surface, 800 to 80,000 kms across and less brilliant than the surrounding regions.

Prominences a large, bright, gaseous feature extending outward from the Sun's surface, often in a loop shape billowing arches of gas represent the completion of the loop of flowing gas

Solar Flares sudden eruptions which spray fountains of very hot gases into space. after 15 to 30 minutes, the explosive phase begins and for 15 minutes or more, the flare gives off x-rays, uv rays, visible light and radio waves occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. solar flares have brought destruction with electrical equipment causing electrical power failure

THE PLANETS

Inner Planets The four planets closest to the Sun are Mercury, Venus, Earth, and Mars. All four of these planets are made up of a rocky material and therefore are called the terrestrial planets. These planets are also known as the inner planets.

Mercury first planet from the Sun a big metal ball of iron contain almost no air just a little bit larger than Earth's moon smallest planet in our solar system fastest moving planet in our Solar System during the daytime the temperature is hotter than an oven; during the night, the temperature is colder than a freezer

Venus second planet from the Sun Earth's closest neighbor and the second brightest object in our night sky has more volcanoes than any of the other planets in our Solar System hottest planet in the Solar Systematmosphere is made up from mainly carbon dioxide. This gas acts like the glass of a greenhouse and keeps the surface of the planet hot enough to melt lead.

Earth third planet from the sun has one moon fifth largest planet in our Solar System Earth’s atmosphere is mainly made up of nitrogen, oxygen, and water vapor. There is a small amount of ozone in our atmosphere and this is what filters some of the damaging radiation from the Sun. The only planet in the solar system with an atmosphere that can sustain life

Mars called the "Red Planet“ fourth planet from the sun very dry and barren, but there is evidence that Mars was once covered with volcanoes, glaciers and flood waters. too cold for liquid water to exist for any length of time, but features on the surface suggest that water once flowed on Mars. Today, water exists in the form of ice in the soil, and in sheets of ice in the polar ice caps.

Outer Planets The remaining 5 planets in our solar system are known as the outer planets: Jupiter, Saturn, Uranus, Neptune and Pluto. The first 4 of these planets are also known as the Gas Giants. Their atmosphere consists mainly of hydrogen and helium. These planets have soupy surfaces and gets denser as you sink to the middle. Not possible to land on. The outermost planet, Pluto, is unique among the outer planets.

Jupiter the largest planet of all of the planets. Its diameter is 11 times larger than Earth’s diameter Its mass is greater than the masses of all the other planets combined. a very stormy planet.

Saturn second largest planet in our Solar System and it is a gas giant like Jupiter lightest planet has beautiful rings made of ice and rocks. its atmosphere is cloudy and windy.

Uranus very cold, windy and, like most of the other planets, poisonous to humans. coldest planet Like Jupiter and Saturn, Uranus is a gas giant. Scientists also believe that on the surface of Uranus there may be a huge ocean. And some scientists think that this ocean may be very hot, maybe even as hot as 2760 degree Celsius.

Neptune a very windy place. No other planet in the Solar System has winds that are as strong as Neptune's the windiest planet has no definite surface layer. Instead, the gas transits into a slushy ice and water layer. most distant planet from the sun, Neptune is the third most massive. Despite its great size, it was the last planet to be discovered, because it lies so far away.

Pluto a dwarf planet. It is rocky and has one big moon. After 76 years of classification as a planet, Pluto was demoted in 2006 to a dwarf planet, in part because of its size but also because of its minor gravitational effects on the bodies around it. It remains one of the most well-known non-planetary bodies in the solar system.