- the study of everything in space beyond the Earth's atmosphere
atoms
- the smallest building blocks of all matter
auroras
- bright bands of glowing light that appear in the skies near the polar regions, caused by the interaction between the Earth's magnetic field and charged particles from the Sun.
axis
- an imaginary straight line around which an object rotates
C
Coronal Mass Ejections
- huge eruptions from the sun's surface that throw out up to 20 billion tons of matter, traveling a million or more miles per hour — the biggest, most violent solar explosions.
D
diameter
- a straight line going through the center of a circle or sphere
dynamic
- active, energetic, and changeable; not static
F
fossil fuels
- a natural fuel such as coal or gas, formed in the past from the remains of living organisms.
G
galaxy
- a collection of thousands to billions of stars held together by gravity
gravity
- the attractive force of a body in space that pulls matter together
L
life cycle
- the series of changes and developments through the course of a lifespan, beginning with birth or formation and ending with death or destruction.
M
magnetic field
- the space around a star or planet where the magnetic force is active
meteorites
- small chunks of rock from space that land on the Earth's surface
N
NASA
- the National Aeronautics and Space Administration, the agency in charge of all space programs for the United States
nebula
- a cloud of dust and gas in space in which a star is born
nuclear fusion
- the process of joining two or more lightweight atoms to form one heavier atom, resulting in release of energy; nuclear fusion takes place in the Sun's core
O
orbit
- the curved path followed by an object in space as it moves around another object.
P
photosynthesis
- The process by which green plants use energy from the sun to make their food and release oxygen into the air
planets
- spherical bodies in space that circles around a central star and reflects that star's light
R
radiation
- the energy or particles released from explosions, chemical reactions, or radioactive materials
revolve
- to move in an orbit around another object, for example: the Earth revolves around the Sun and the moon revolves around the Earth.
rotate
- to spin around a center point or axis
S
satellites
- objects that orbit another object, whether natural (the moon) or man-made (spacecraft)
solar cells
- batteries or panels that can capture sunlight and turn it into electricity
solar eclipse
- an event that takes place when the moon moves between the Sun and the Earth, blocking out the sun and casting a shadow on the Earth.
Solar flares
- bursts of energy and particles from the sun that release gases, radiation, and magnetic storms
solar system
- the Sun, and all the planets and other objects that orbit around it.
solar wind
- the constant stream of particles and energy emitted by the Sun
star
- a ball of shining gas, held together by its own gravity, that emits energy into space
Sunspots
- a dark area on the sun's surface that is cooler than the area around it
T
telescope
- an instrument that can make faraway things appear closer
U
universe
- all of space, time, matter, and energy in existence
