	Basic Level (8-12) years old
				When the indicator is fully coloured, there is material specifically developed for that level.
	Intermediate Level (12-15) years old
				When the indicator is half-coloured, the material from another level may be appropriated for this level. Give it a look!
	Advanced Level (15-18) years old
				When the indicator has no colour at all, the Science Case is not recomended for that level.
	Super Hero Level (Early University)

Galaxies are fundamental building blocks of the Universe. Some are simple, while others are very complex in structure; some have enormous sizes and contain trillions of stars, while others are very small and contain only hundreds of thousands of stars; some are yellowish and other display a variety of colours, from red to blue. As we live in one galaxy, the Milky Way, it is interesting to know the different galaxy compositions and the analogies and differences with other galaxies.