Science Chapter 9

The galaxy of our solar system is in. Appears as a hazy white band in the night sky.

A huge collection of stars, planets, dust, and gas held together by gravity

A collection of stars held by gravity

A collection of 50 to 1000 stars. They appear along the main band of the milky way

A collection of 100 000 to 1 000 000 stars. Arranged in a distinct spherical shape and appear around the centre of the milky way.

The small group of galaxies that includes the Milky Way

A massive cluster of 4 to 25 clusters of galaxies, hundreds of millions of light-years in size.

Be Spiral, elliptical, or irregular. Spiral galaxies look like a pinwheel/whirlpool. Elliptical galaxies can be perfectly spherical to the shape of a football, and irregular galaxies have no common shape.

The study of the universe. Cosmologists try to answer questions about universe.

The change in frequency of a light source's motion relative to the Observer, or the change in the pitch of sound relative to the Observer.

The effect where an object is moving away from an Observer has it's wavelengths lengthened, towards the red end of the spectrum.

The effect where an object is moving towards an observer has its wavelengths shortened, towards the blue end of the spectrum.

The event which may have caused the universe to start expanding 14 billion years ago.

The radiation left over from the big bang which fills the universe

Electromagnetic waves traveling through matter.

The most abundant form of matter in the universe. Invisible to telescopes and makes up 23% of the universe.

A form of energy that takes up about 73% of the universe, and has the effect of increasing the expansion of the universe.