|Gravity||The force that causes objects with
mass to attract one another.
|Gravitational Attraction||The force that pulls two objects towards each other; the
greater the mass of and object, the greater the attraction;
the further apart the objects, the weaker the attraction.
|Newton’s Law of
|The law that says every object in the universe attracts
every other object, and that the force is affected by mass
and distance: the greater the mass of an object, the
greater the attraction; the farther apart the objects, the
weaker the attraction.
|Mass||The amount of matter in an object|
|Space Exploration||The investigation of physical conditions in space
and on stars, planets, and other celestial bodies
through the use of satellites, space probes, or
spacecraft with human crews.
|Rocket||An engine that provides thrust directly through the
burning of its fuel without requiring the intake of air.
|Spacecraft||A vehicle or device designed for travel or
operation outside Earth’s atmosphere.
|Space Shuttle||A reusable spacecraft designed to transport
people and cargo between Earth and space.
|Space Probe||An unmanned spacecraft designed to explore the
solar system and transmit data back to Earth.
|Rover||A vehicle for exploring the surface of an
extraterrestrial body (such as the Moon and Mars).
|Satellite||Something that orbits around another object; for
example, a moon orbiting a planet or
a human-made object orbiting Earth.
|Telescope||An instrument for viewing or
detecting distant objects.
|Observatory||A building or place given over to or
equipped for observation of natural phenomena.
|International Space Station||An orbiting space satellite, construction of which
began in 2001 with the cooperation of 16 nations;
used for scientific and space research.
|Galileo Galilei||The father of modern science; made
improvements to the telescope and discovered
the four largest moons of Jupiter, among many
other scientific accomplishments.
|Astronauts||A person trained to be part of a spacecraft crew|
|NASA||National Aeronautics and Space
Administration; the American governmental
agency dedicated to space exploration.