Seconds Left: Diagram a comet

Describe GALAXY Seconds Left:

A galaxy contains stars, gas, and dust which are held together as a group by gravity. There may be millions, or even billions, of stars in one galaxy. There are billions of galaxies in the universe.

Seconds Remaining: How are galaxies classified?

Galaxies are classified according to their shape. Some galaxies are called "spiral", because they look like giant pinwheels in the sky. The galaxy we live in, the Milky Way, is a spiral galaxy. Some galaxies are called “elliptical", because they look like flat balls. A galaxy may be called "irregular" if it doesn't really have a shape. A new type of galaxy was discovered recently, called a "starburst" galaxy. In this type of galaxy, new stars just seem to 'burst out' very quickly.

Seconds Left: Describe STAR

A star is a brilliantly glowing sphere of hot gas whose energy is produced by an internal nuclear fusion process. Stars are contained in galaxies. ml

Seconds Left: What is the Hertzsprung- Russell Diagram?

A tool that shows relationships and differences between stars. It shows stars of different ages and in different stages

Seconds Left: Diagram the life cycle of a star

Seconds Left: Describe the types of stars

Main Sequence Stars - maintains a stable nuclear reaction. Red Giants - a large star that is reddish or orange in color. It represents the late phase of development in a star's life, when its supply hydrogen has been exhausted and helium is being fused White Dwarfs - the remnant of an average- sized star that has passed through the red giant stage of its life. After the star has used up its remaining fuel.