Bigger than Big- Term 2 2023 (copy)

Light year

the distance light travels in one year

galaxy

a giant group of dust, gas, and stars held together by gravity

universe

space and all matter in it

Solar System

a system made up of the Sun, the eight planets and their moons, dwarf planets, and smaller objects

gravity

a force that pulls two objects toward each other

Star

large hot spheres of hydrogen gas powered by nuclear fusion reactions in the core

Asteroid belt

an area between the orbits of Mars and Jupiter where most asteroids are located

planet

A large body in space that orbits a star and does not produce light of its own

Moon

an object that orbits a planet or a dwarf planet

outer planet

a planet made up mostly of gases and is called a gas giant

atmosphere

a collection of gases that surround a planet

inner planet

a planet made up of rocks or metals with a solid surface

Galaxy

a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

Astronomical Unit

The average distance between Earth and the sun, about 150 million kilometers

neutron star

a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons

Black hole

An object whose gravity is so strong that nothing, not even light, can escape.

White Dwarf

A small, hot, dim star that is the leftover center of an old star

red giant

A star that expands and cools once it runs out of hydrogen fuel

supernova

A gigantic explosion in which a massive star collapses and throws its outer layers into space

Parallax method

A method for measuring the distances to nearby stars that relies on the fact that a star appears displaced relative to the background of distant stars when viewed from two different positions in space. Satellites orbit outside the Earth's atmosphere can measure distances up to almost 1000 pc in this way.

Supernova

A gigantic explosion in which a massive star collapses and throws its outer layers into space

Edwin Hubble

research proved universe still expanding;

proved galaxies exist outside of the milky way;

classification system for galaxies;

hubble telescope named after him

radiotelescope

a telescope that picks up sound waves from very distant stars

space telescope

Telescopes in orbit above Earth's atmosphere.

telescope

A device built to observe distant objects by making them appear closer

Infra-red

This has wavelengths that are longer than visible light, and can be felt as heat.

infrared telescope

Telescope designed to detect infrared radiation

Big Bang Theory

Cosmological model that explains the sudden development of the universe through expansion from a hot, dense state.

Steady State Theory

a theory which states that there was no beginning to the universe and that the universe does not change in appearance.

Life cycle of a star

the series of events that occurs in the life of any star

Hertzsprung-Russell diagram

organizes the family of stars into a diagram; across bottom is star's temperature and side is star's absolute magnitude; a star's temperature and color depend on how big the star is

cosmic radiation

Naturally occurring background radiation from outer space.

greenhouse effect

warming that results when solar radiation is trapped by the atmosphere

climate change (global warming)

A rise in the average temperature of Earth's atmosphere and oceans. It is caused by increased concentrations of greenhouse gases in the atmosphere, resulting from human activities such as deforestation and burning of fossil fuels.

ozone layer depletion

loss of ozone molecules in atmosphere resulting in increase in harmful solar radiation reaching ground level

loss of biodiversity

declining number and variety of the species in an area

rising sea levels

the increased height of the level of seas and oceans