Words To Know

Analogue: a location or object seen to be similar and comparable. read more >>

Asteroid: a rocky object in our Solar System that is smaller than a planet read more >>

Asteroid belt: a region in our Solar System between Mars and Jupiter where the majority of asteroids that orbit the Sun can be found read more >>

Astrobiology: the study of the origin, evolution, and distribution of life in the universe read more >>

Astronaut: someone who has been trained to be a crew member of a spacecraft. read more >>

Atmosphere: the gases that surround a planet read more >>

Bacteria: single-celled micro-organisms, thought to be similar to the first life on Earth read more >>

Barred-spiral galaxy: a spiral galaxy with a center that looks stretched out in one direction read more >>

Barren: having little or no life; barren land has little plant life.

By-product: a second product that is made while you are trying to make a main, first product. read more >>

Caldera: a volcanic crater that forms when a volcano collapses after a large eruption read more >>

Capacity: the largest amount that something can hold or make.

Capsule: the part of a spacecraft that has been designed to hold the crew and survive re-entry into the Earth's atmosphere. read more >>

Carbon: one of the most common chemicals in the universe; all life we know of is carbon-based read more >>

Celestial: relating to the sky or space.

Celestial body: a planet, sun, or other object that exists in space. read more >>

Channel: a groove in the land, often formed by the flow of a fluid, such as water or lava.

Classification: a process of grouping things together or naming things based on their similarities or identification. read more >>

Clinker: very irregularly shaped lava crust fragments.

Comet: an small (<20 miles across) object in space made of mostly ice and rock that often has a tail of gas and dust when passing by the sun read more >>

Composition: the different materials that something is made out of.

Compound: made of two or more parts or elements read more >>

Consume: to use up or eat.

Cosmic radiation: high-energy radiation (energy waves or particles) that mostly comes from outside of our galaxy. read more >>

Cosmonaut: another word for astronaut; most commonly, a Russian astronaut.

DNA: deoxyribonucleic acid; the molecule which contains genetic instructions for life read more >>

Drake equation: an equation used to discuss the number of intelligent civilizations currently existing in the Milky Way with which humans could communicate read more >>

Dwarf planet: a planetary body which is large enough to be a planet, but has not become the dominant planetary body in its orbit read more >>

Edge-on: how to describe spiral galaxies that we can see from the side.

Eject: the throw or be thrown out of another object, such as case dust particles shooting out of a dying star.

Electron: a particle smaller than an atom that has a negative charge and is an important part of atoms read more >>

Element: a substance that is made from a single type of atom; elements are the foundation of all materials.

Elliptical: oval shaped, not quite a circle or a sphere read more >>

Elliptical galaxy: a galaxy with little shape; it looks like a cloud of stars read more >>

Embankment: a raised area of land, often on the side of a river or other channel.

Enceladus: a moon of Saturn, and the brightest object in the Solar System due to its surface of ice read more >>

Europa: a moon of Jupiter, and the 6th-largest moon in the Solar System read more >>

Expedition: a journey made for a specific purpose.

Extraterrestrial: relating to things outside of the Earth; relating to space and celestial bodies beyond Earth.

Extrude: to force out or push.

Face-on: how to describe spiral galaxies that we can see from above, showing the spiral arms, for example.

Flyby: an action in which a spacecraft passes close to another object without orbiting it. read more >>

Fossil: a trace (or sign) of an organism living in a past geological period; can be actual remains of a body or an impression of a body or body parts read more >>

Fragment: to break large pieces of material into smaller pieces.

Frictional heat: the heat made by rubbing two things together.

Galaxy: a group of stars that are held together by gravity read more >>

Gamma radiation: a very energetic light that can cause damage to DNA very quickly read more >>

Geologist: a scientist that studies the Earth and other land-based planets, their rocks and other materials, and how they change over time read more >>

Greenhouse gas: a gas that can absorb and give off energy in a certain wavelength; greenhouse gases are the main contributors of current climate change. read more >>

Hydrothermal vent: an area on the seafloor which spews hot water heated from magma read more >>

Ignition: the process of starting the launch of a rocket, in which fuel is used to lift the rocket away from the surface of Earth.

Inclusion: individual pieces of material that are different from the material surrounding them.

Irregular: having an atypical shape.

Irregular galaxy: a galaxy that does not appear to have a typical shape read more >>

Jagged: something that has sharp pieces or sharp points sticking out of it.

Lander: a spacecraft capable of safely landing on a planetary surface. read more >>

Landform: a feature or formation on the surface of a planet. read more >>

Launch pad: the structure and location from which rockets lift off. read more >>

Lava: melted rock that erupts or comes out of the ground of a planetary body read more >>

Lunar eclipse: when the Sun, Earth, and Moon are aligned and the Moon passes behind Earth, into its shadow read more >>

Magma: the hot molten fluid that forms when rocks melt inside the Earth; once magma erupts and cools, it forms new volcanic rocks read more >>

Magnetic: when a material produces a magnetic field (that attracts certain metals) read more >>

Mantle: the layer of a planet that is found between the core and the crust read more >>

Meteor: a rock from space that travels through part of Earth's atmosphere.

Meteorite: a rock from space that lands on Earth read more >>

Meteoroid: a rock in space that is somewhere between a pebble to a meter-wide boulder in size read more >>

Mineral: solid, inorganic (do not come from plants or animals) substances that occur naturally. Minerals make up sand, soil and rocks.

Mission: a specific travel assignment or trip into space.

Molten: something that is liquified due to heat.

Multicellular: an organism made of more than one cell read more >>

Ode: a poem or other writing, usually written to honor a certain person or subject. read more >>

Orbit: to follow the path of an orbit; an oval or circular path that an object follows around a larger object tdue to the attraction of the large object’s gravity; an object that orbits can be called an orbiter or a satellite.

Orbiter: a space platform with analytical instruments and cameras orbiting a planetary body such as a planet or a moon. read more >>

Organic carbon: organic carbon is a compound where carbon atoms are directly bonded to other carbon atoms; organic carbon is the primary building block for all forms of life on Earth.

Organic compounds: small molecules which contain carbon and are important for life read more >>

Organism: a living thing read more >>

Panspermia: Greek for “seeds”, a theory for the origin of life which says life did not begin on Earth, but began somewhere else and was transported to Earth read more >>

Photosynthesis: a set of reactions that change light energy into chemical energy. Photosynthesis also produces energy-rich carbohydrates like starch. Photosynthesis occurs in the chloroplast of a plant cell read more >>

Planet: the large, ball-shaped objects in orbit around stars, particularly the eight planets in our own solar system.

Planetary body: a planet or moon present in our solar system. read more >>

Radar: radio waves that are used to measure characteristics of an object read more >>

Radioactive decay: when an element is unstable, it emits energy in the form of radiation and forms a more stable element.

Reconnaissance: observation or research on a location that is done before visiting, to learn information about the location.

Reliability: the amount something can be depended on to perform a function.

Remote sensing: studying an object from far away, without physically touching it. read more >>

Robot: any machine that completes a complex task, usually under human direction. read more >>

Rock: a solid mineral-based material that forms part of the ground on a planetary body read more >>

Rocket: a vehicle that travels by controlling exploded fuel. read more >>

Rover: a space exploration vehicle that can move around on the surfaces of planets, moons, or other objects in the Solar System. read more >>

Rubbled: material that has been ground up into smaller pieces.

Rubbly: a rubbled texture on the surface of a lava flow.

Satellite: any object that orbits another object in space. read more >>

Sediment: small bits of materials that have been broken down, often from rocks read more >>

Spacecraft: a vehicle used for traveling in space, can either be entirely robotic or can be built to carry people.

Spectrometer: a tool that measures wavelengths of light read more >>

Spiral: a shape created by curving a line around its starting point; for example, when you roll up a matt, if you look at the edge you will see a spiral. read more >>

Spiral galaxy: a galaxy where the stars, gas and dust are grouped into arms that twist around the center read more >>

Star: a ball of hot, dense material held together by its own gravity read more >>

Surface roughness: the texture of a surface. read more >>

Target: a desired destination or object.

Technique: a way of completing a task or job.

Terrestrial planet: a planet made mostly of rocks and metals. In our Solar System, the terrestrial planets are Mercury, Venus, Earth, and Mars read more >>

Texture: the feel of an object (e.g., hard, soft, smooth, slimy, rough are all textures).

Thruster: a small engine on a spacecraft that is used to make small adjustments to direction of travel. read more >>

Universe: all existing material and space that we can observe considered as a whole. read more >>

UV radiation: highly energetic light that can cause damage to DNA over time read more >>

Vast: very large.

Velocity: the rate of change in an object's position. read more >>

Viscosity: the measure of a fluid's resistance to flow. read more >>

Volcanic vent: an opening of a volcano or a rift beneath a magma chamber. read more >>

Volcano: an opening in the Earth's crust through which rock, lava, or smoke exits or has exited; often surrounded by a mountain, hill, or landform of some type read more >>

How Do We Know the Earth Is Round?
Answer »

Be part of Ask An Anthropologist

By volunteering, or simply sending us feedback on the site. Scientists, teachers, writers, illustrators, and translators are all important to the program. If you are interested in helping with the website we have a volunteers page to get the process started.

Donate icon  Contribute