Grade 8

• Axis - an invisible line around which an object rotates, or spins. 
• Northern Hemisphere - gets the most sunlight. Creating summer.
• Monsoons - a seasonal change in the direction of the prevailing, or strongest, winds of a region
• Two Monsoons of the Philippines - Amihan and Habagat
• Solar Eclipse - A solar eclipse occurs when the Moon passes between the Earth and the Sun, blocking out the Sun.
• Lunar Eclipse - The Moon passes between the Earth and the Sun, causing it to appear red.
• Nebular Theory - The idea that the Sun and planets formed from a cloud of gas and dust.
• AMU stands for - Astronomical Units
• 9.46T Kilometers - Distance of One Light Year
• Cosmology - study of the origin and structure of the universe.
• Shapes of orbits - elliptical, circular, parabolic, hyperbolic
• Galileo Galilei - He was the first person to use a telescope to observe the moon and sun.
• Gravitational Force - A force between two objects with mass that pulls them together.
• Meteorite - A rock that has fallen from space and landed on Earth.
• Meteroid - Small, rocky, and irregularly shaped objects that orbit the Earth.
• Nitrogen - is the most abundant element in the atmosphere.
• Precambrian - is the earliest of the geologic ages, which are marked by different layers of sedimentary rock. Laid down over millions of years, these rock layers contain a permanent record of the Earth's past, including the fossilized remains of plants and animals buried when the sediments were formed.
• Paleozoic - major interval of geologic time that began 538.8 million years ago with the Cambrian explosion, an extraordinary diversification of marine animals, and ended about 252 million years ago with the end-Permian extinction, the greatest extinction event in Earth history.
• Stages of the Paleozoic - Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian
• Mesozoic - second of Earth’s three major geologic eras of Phanerozoic time. Its name is derived from the Greek term for “middle life.”
• Stages of Mesozoic - Triassic, Jurassic, and Cretaceous
• Cenozoic - third of the major eras of Earth’s history, beginning about 66 million years ago and extending to the present. It was the interval of time during which the continents assumed their modern configuration and geographic positions and during which Earth’s flora and fauna evolved toward those of the present.
• Phanerozoic Eon - is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present and began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.
• Igneous - rocks formed from molten rock that cools and solidifies.
• Sedimentary - The process of the accumulation of sediment, such as sand, silt, and clay, over a period of time.
• Metamorphic - A rock that has been changed by heat and pressure from its original state.
• Fossils - remains of organisms from millions of years ago.
• Climate - The average weather conditions in a particular area over a long period of time.
• Weather - The state of the atmosphere at a particular place and time.
• Atmosphere - The gases that surround the Earth and make up the air.
• Hydrosphere - is made up of all those areas on the surface of the earth that are covered in water or ice. Oceans and seas, rivers and lakes, glaciers and underground water, even the water vapor in the atmosphere
• Water Cycle - The movement of water from the atmosphere to the ground and back to the atmosphere.
• Greenhouse Effect - The process by which the earth's atmosphere traps heat from the sun.
• CFC stands for - Chlorofluorocarbon
• Earthquake - A sudden shaking of the ground caused by movements within the earth's crust.
• Global warming - An increase in the average temperature of the earth's atmosphere over a period of years resulting mainly from the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, methane, and other pollutants.
• Ozone layer - A thin layer of gas high above the earth's surface that contains ozone (O3). It protects us from most of the ultraviolet radiation coming from the sun.
• Barometer - A device used to measure atmospheric pressure and used to predict weather.
• Thermometer - A device used to measure temperature.
• Anemometer - A device used to measure the speed of the wind.