Venus has a massive underground lava tube

astronaut: Someone trained to travel into space for research and exploration.

atmosphere: The envelope of gases surrounding Earth, another planet or a moon.

data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

electronics: Devices that are powered by electricity but whose properties are controlled by the semiconductors or other circuitry that channel or gate the movement of electric charges.

gravity: The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its gravity.

insight: The ability to gain an accurate and deep understanding of a situation just by thinking about it, instead of working out a solution through experimentation.

lava: Molten rock that comes up from the mantle, through Earth’s crust, and out of a volcano.

Mars: The fourth planet from the sun, just one planet out from Earth. Like Earth, it has seasons and moisture. But its diameter is only about half as big as Earth’s.

meteorite: A lump of rock or metal from space that passes through Earth’s atmosphere and collides with the ground.

molten: A word describing something that is melted, such as the liquid rock that makes up lava.

moon: The natural satellite of any planet.

NASA: Short for the National Aeronautics and Space Administration. Created in 1958, this U.S. agency has become a leader in space research and in stimulating public interest in space exploration. It was through NASA that the United States sent people into orbit and ultimately to the moon. It also has sent research craft to study planets and other celestial objects in our solar system.

planet: A large celestial object that orbits a star but unlike a star does not generate any visible light.

plate tectonics: The processes governing the movements of massive pieces that make up Earth’s outer layer, which is called the lithosphere. Those processes cause the rock masses to rise from inside Earth, travel along its surface, and sink back down.

pressure: Force applied uniformly over a surface, measured as force per unit of area.

radar: A system for calculating the position, distance or other important characteristic of a distant object. It works by sending out periodic radio waves that bounce off of the object and then measuring how long it takes that bounced signal to return. Radar can detect moving objects, like airplanes. It also can be used to map the shape of land — even land covered by ice.

radiation: (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.

resolution: (in optics) A term having to do with the degree of clarity or detail with which some object can be seen. (v. resolve)

solar: Having to do with the sun or the radiation it emits. It comes from sol, Latin for sun.

tectonic: Surface activity on a large rocky body (such as a planet or moon) as liquid rock flows up to the surface where it solidifies, then slowly drifts atop molten rock, carrying surface features with it.

Venus: The second planet out from the sun. Just as Earth does, it has an iron core and a rocky mantle and crust. Volcanoes on the planet’s surface spewed high levels of carbon dioxide, which built up in the planet’s atmosphere. Today the air pressure at the planet’s surface is 100 times greater than on Earth, and the atmosphere now keeps the surface of Venus a brutal 460° Celsius (860° Fahrenheit).

volcano: A place on the crust of Earth (or another planet) that opens, allowing magma and gases to spew out from underground reservoirs of molten material. The magma rises through a system of pipes or channels, sometimes spending time in chambers where it bubbles with gas and undergoes chemical transformations. This plumbing system can become more complex over time. This can result in a change, over time, to the chemical composition of the lava as well. The surface around a volcano’s opening can grow into a mound or cone shape as successive eruptions send more lava onto the surface, where it cools into hard rock.