🌌 Earth & Space Science - Space Unit Study Guide 🌌

Big Bang Theory

The theory that the universe began as a single point and has been expanding ever since.

Redshift

When light from galaxies shifts toward the red end of the spectrum, indicating they are moving away.

Blueshift

When light shifts toward blue, indicating that an object is moving toward us.

Cosmic Microwave Background (CMB)

Faint radiation left over from the Big Bang, found everywhere in the universe.

Electromagnetic Spectrum

The full range of light waves, including visible light, infrared, ultraviolet, X-rays, etc.

Absorption Spectrum

A spectrum with dark lines where certain wavelengths are absorbed by elements in a star's atmosphere.

Emission Spectrum

A spectrum with bright lines, showing specific wavelengths emitted by a gas.

Continuous Spectrum

A complete rainbow of colors, created by hot, dense objects.

Doppler Effect

The change in wavelength due to motion, used to explain redshift and blueshift.

Kepler's First Law

Planets move in elliptical orbits with the Sun at one focus.

Kepler's Second Law

Planets move faster when closer to the Sun and slower when farther away.

Kepler's Third Law

The farther a planet is from the Sun, the longer its orbit takes.

Nebula

A cloud of gas and dust where stars are born.

Protostar

A forming star before nuclear fusion begins.

Main Sequence

The stable phase where stars fuse hydrogen into helium.

Red Giant / Supergiant

A star that has run out of hydrogen and starts fusing heavier elements.

Supernova

A massive explosion at the end of a large star's life.

White Dwarf

A small, hot, but dim core of a dead low-mass star.

Neutron Star

A dense, collapsed core left after a supernova, made mostly of neutrons.

Black Hole

A region of space with gravity so strong that nothing can escape.

H-R Diagram

A graph that plots stars based on temperature and luminosity (brightness).

Main Sequence Stars

Stars in the stable phase, includes the Sun.

Red Giants/Supergiants

Large, bright, but cooler stars.

White Dwarfs

Small, hot, but dim remnants of dead stars.

Constellations

Patterns of stars in the sky that appear to move due to Earth’s rotation and orbit.

Earth's Rotation

Causes daily movement of stars, making them appear to rise and set.

Earth's Revolution

Causes seasonal changes in visible constellations.