Glossary of Terms
- Absolute dating The process of determining an age on a specified chronology in archaeology and geology.
- Campanile A tower that contains one or more bells, or that is designed to hold bells even if it has none.
- Cinder cone The simplest type of volcanoes. They are hills, often steep, formed by an accumulation of congealed lava around a vent.
- Circumference The length of the circle if it were opened up and straightened out to a line segment.
- Diameter Any straight line segment that passes through the center of the circle and whose endpoints lie on the circle
- Dwarf Planet A planetary-mass object that is neither a planet nor a natural satellite.
- Earth Day Approximately the period of time during which the Earth completes one rotation with respect to the Sun. It is 24 hours.
- Earth Science A broad branch of science that deals primarily with the study of physical constitution of the earth and its atmosphere.
- Earth Year A year is the orbital period of the Earth moving in its orbit around the Sun.
- Fissure vent Also known as a volcanic fissure or eruption fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity.
- Gas Giant A giant planet composed mainly of hydrogen and helium.
- Hubble Telescope The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation up to this day.
- Ice Giant A giant planet composed mainly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur.
- Igneous Rock also known as magmatic rock, is formed through the cooling and solidification of magma or lava.
- Landform A natural feature of the earth's surface.
- Lava dome A type of volcano characterize by a dome. This dome are formed when small masses of lava flow over the volcano's vent and accumulate around it.
- Mass Both the property of a physical body and the measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.
- Metamorphic Rock A rock that have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form due to high heat and high pressure.
- Natural Satellite An astronomical body that orbits a planet or minor planet. Also known as moon.
- Orbital Speed The speed at which an astronomical body orbits around another body, i.e. the sun.
- Radius A straight line from the center to the circumference of a circle or sphere.
- Rainforest A forest characterized by high rainfall.
- Relative dating The science of determining the relative order of past events without necessarily determining their absolute age. Ex: the age of an object compared to another.
- Sedimentary Rock are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water.
- Shield Volcano A type of volcano usually composed almost entirely of fluid lava flows. It is named for its low profile, resembling a warrior's shield lying on the ground.
- Solar Mass A standard unit of mass in astronomy, equal to approximately 2×1030 kg.
- Specimen A sample of a substance or material for examination or study.
- Star A type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
- Stratovolcano Also known as Composite volcanoes, is a conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash.
- Terra Firma Refers to the Solid earth; the planet Earth's solid surface and its interior.
- Terrestrial Planet A planet that is composed primarily of silicate rocks or metals. Also known as telluric planet, or rocky planet.
- Volcanic Explosivity Index (VEI) A relative measure of the explosiveness of volcanic eruptions. It was devised by Chris Newhall of the United States Geological Survey and Stephen Self at the University of Hawaii in 1982.
- Volume The quantity of three-dimensional space enclosed by a closed surface