... Majestic on a truly cosmic scale, M100 is appropriately known as a Grand Design spiral galaxy. ... This picture gives an indication of Saturn's extensive ring system, which can be seen casting a shadow on the planet, as does Tethys. ... Like cosmic snowballs, fluffy comet-like objects the size of houses and composed mostly of water-ice, may be pummeling planet Earth 5 to 30 times a minute. ... Neptune, the Solar System's outermost gas giant planet, is 30 times farther from the Sun than Earth. ...