Exploring the Cosmos

Comparing stars and planets

• Stars emit light; planets emit light

• Stars reflect light; planets emit light

• Stars emit light; planets reflect light

• Stars and planets both emit light

Planning a model of the cosmos

• stars

• oceans

• mountains

• forests

Nebula

• A large planet in the solar system

• A region of gas and dust in space, birthplace of stars

• A type of star that has exploded

• A black hole that consumes everything around it

Applying the concept of a light-year

• to measure distances between stars and galaxies

• to measure the speed of light in a vacuum

• to calculate the age of the universe

• to determine the brightness of stars

Main components of the cosmos

• planets

• stars

• comets

• black holes

Milky Way

• galaxy containing our Solar System

• a type of star

• a planet in our Solar System

• a black hole

Identifying a nebula’s importance

• are regions where new stars form

• are remnants of dead stars

• are clouds of gas and dust in space

• are areas of high radiation

Gravity’s role in the cosmos

• holds planets, stars, and galaxies together

• creates black holes in space

• causes the expansion of the universe

• is responsible for the formation of comets

Solar System

• and objects orbiting it, like planets and asteroids

• the center of the Milky Way galaxy

• a collection of stars and galaxies

• the region beyond Pluto

Cosmos definition

• universe as an ordered, harmonious system

• a chaotic collection of stars and planets

• a scientific theory about the origin of life

• a philosophical concept of existence