Facts About Space
(I collected these while introducing the Space Travel Debate to my classes)

Speed of light is 186,000 miles/second.

Speed of sound is anywhere from 660 miles/hour to 761 miles/hour, which is Mach 1, depending on altitude (sound is fastest at sea level).

Negative G's happen when a jet dives and the pilot feels less and less weight.
0 G = weightlessness
1G = our regular weight on earth (1 atmosphere of air pressure or earth's gravity)
2 g's = 19.6133 m/s2
1 meter/second = 2.23693629 mph

Earth's atmosphere goes up over 560 kilometers (348 miles) from the surface. Earth's atmosphere is pressing against each square inch of you with a force of 1 kilogram per square centimeter (14.7 pounds per square inch).

The Space Shuttle reaches a speed of 7860 m/s (about 17,543 mph) while in orbit. Since Mars is 48.5 million miles from earth, at that rate it would take a space shuttle about 7 months to reach Mars. If astronauts lose anywhere between 2 to 3% of bone matter every month they are in microgravity, they would reach Mars with anywhere from 14 to 21% bone loss. And Mars has 1/3 the gravity Earth has with a very thin atmosphere.

To leave our atmosphere, the space shuttle needs to reach the Earth escape velocity of 11.2 kilometers per second, or 25,805 miles per hour.

Galaxies are made up of millions and billions of stars and there are billions of galaxies.

Our galaxy is made up of 200 billion stars. The bulge, at the centre of the galaxy, is a flattened spheroid. This is a high density region where Population II stars predominate---stars which tend toward red and are very old, about 10 billion years. The universe is supposedly 13.7 billion years old, give or take .2 billion years.

Light year: Distance light travels in a year = almost 6 trillion miles! 5,800,000,000,000 miles and that's only 1 light year.

Galaxies move at about 2 million miles per hour and some are billions of light years away from us!!! Galaxies do collide.

Andromeda is closest to Milky Way, 2.2 million light years away.

Scientists think that Andromeda and Milky Way will collide in 3 billion years. The collision would last about 1 billion years.

Sources:
http://www.ccsn.nevada.edu/planetarium/galaxy.html

http://www.aerospaceweb.org/question/atmosphere/q0102c.shtml

http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html

http://kids.earth.nasa.gov/archive/air_pressure/

http://hypertextbook.com/facts/2001/InnaSokolyanskaya1.shtml

http://visitor.broaddaylight.com/spacekids/TFAQ3.shtm

http://www.marsacademy.com/traj/traj2.htm

http://www.astronomycafe.net/qadir/q1167.html

http://antwrp.gsfc.nasa.gov/apod/ap030217.html

http://www.cita.utoronto.ca/~dubinski/tflops/

http://www.damtp.cam.ac.uk/user/gr/public/gal_milky.html

http://antwrp.gsfc.nasa.gov/apod/ap991114.html

http://www.voodoo.cz/falcon/agf.html

http://www.nasa.gov/multimedia/imagegallery/image_feature_142.html

http://eagle.csd49.org/classpages/space_debate.html#space_travel_debate_links