The distance light can travel in one year is ______________

What unit of measurement is used to calculate distance in our universe?

True or False: The universe is expanding.

True or False: Scientist still consider the sun the center of the universe

Wavelengths of light appear to become longer during a ____________.

A popular theory of the origin of the universe is _____________

What element is the most plentiful in the universe?

a location where hydrogen atoms fuse into helium atoms, releasing large amounts of light and gamma radiation.

Area in the universe that is characterized by a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette.

a collection of stars around a gravitational center.

extremely remote celestial object, emitting exceptionally large amounts of light energy, and typically having a starlike image in a telescope.

This is an example of a _______________ galaxy.

This is an example of a ____________ galaxy.

This is an example of a ____________ galaxy