The colors in the spectrum of a side moving toward earth are shifted slightly toward blue.
A star that suddenly becomes brighter.
An observed change in the frequency of a wave when the source or observer is moving.
A large celestial body that is composed of gas and that emits light.
14 billion years ago, a sudden event that sent all matter and energy outward in all directions.
The coldest temperature possible.
Nightly luminous stars from main sequence stars that are more massive than the sun, which becomes larger than giants in their third stage.
A large cloud of gas or dust in interstellar space; a region in space where stars are born.
an object so massive and dense that even light cannot escape its gravity.
Pair of stars that revolve around each other and are held together by gravity.
A collection of stars, dust, and gas bound together by gravity.
The total amount of energy stars give off each second.
The brightness of a star as seen from earth.
The study of the origin, properties, and evolution of the universe.
A spiral galaxy in which the sun is one of hundreds of billions of stars.
Any of the large celestial bodies that revolve around the Sun in the solar system
a small object that enters Earth's atmosphere from space and burns due to friction, emitting light
The four largest and brightest moons of Jupiter, which were discovered by Galileo Galilei: Ganymede, Io, Callisto, and Europa
Large and small rocks or metallic masses orbiting the Sun; made up of materials similar to those that formed the planets
A celestial body of ice, dust, and rock with an elongated and elliptical orbit
the force that causes objects with mass to attract one another
the whole mass of air surrounding a planet
move in an elliptical path around a center
The gravitationally-curved path of an object around a point in space
To spin on an axis; the spinning of Earth on its axis that causes day and night to occur
Composition of outer planets whose atmosphere is made of gases
relating to the land
The region between the inner and outer planets where most asteroids orbit around the Sun
A reusable spacecraft designed to transport people and cargo between Earth and space
A vehicle or device designed for travel or operation outside Earth's atmosphere
a large artificial satellite used as a long-term base for manned operations in space.
An unmanned spacecraft designed to explore the solar system and transmit data back to Earth
an engine that provides thrust directly through the burning of its fuel without requiring the intake of air
A vehicle for exploring the surface of an extraterrestrial body (such as the Moon and Mars)
National Aeronautics and Space Administration; the American governmental agency dedicated to space exploration