Did you know? - size and density
Kepler 7B, a newly found giant exoplanet, has the density of a styrofoam cup.
Betelgeuse, a star in the Orion Nebula (photo above) which appears orange in colour, is so big that if it was placed where our Sun is, it would swallow up Mercury, Venus, Earth, Mars and Jupiter.
Olympus Mons, on Mars, is the largest volcano in the solar system at nearly three times the height of Mt Everest