Why do we explore space - for practical or other reasons?

PRACTICAL:
1. Mineral rights whereas I insist the first trillionaire in history will gain his or her wealth from establishing a mining empire from this industrial practice;
2. Future home worlds;
3. Detection/prevention of Earth shattering asteroids, comets, etc... objects.

ACADEMIC:
1. Furthering astronomical sciences including the history of our galaxy and universe;
2. Finding other life and civilizations that may(may have) exist(ed) in other solar systems and galaxies;
3. General curiosity that may or may not kill the proverbial cat.

I guess we are doing that for many purposes. We are still looking for a planet that is like Earth and also we are looking for some forms of life on other planets like Mars or Venus.

Space exploration funnels lots of money into top universities and sophisticated aerospace firms, which work on inventing new materials and applying new technologies. These discoveries are often recognized to have marketable properties which can be developed into commercial products and processes used right here on planet earth. Military spending has long had a similar effect on stimulating research which subsequently can be employed in the civilian market, especially medical breakthroughs and communication technology.