Waterproof Tear-Resistant Stargazer Map and Guide. The name Solar System is derived from "Sol" or sun, and describes our planetary system orbiting our sun. Nearest the sun are the four terrestrial planets: Mercury, Venus, Earth, and Mars. All are dense, with solid surfaces and iron cores, but conditions on them vary widelywet and temperate on Earth, freezing and dry on Mars, scorching and dry on Mercury and Venus. The outer solar system is where gas giants reside. Jupiter and Saturn are nearly all atmosphere over a small dense core. Uranus and Neptune appear to have much larger solid cores relative to their size under their hydrogen-helium veils. The Solar System Stargazer Map and Guide includes detailed images of the planets and a striking comparison of all of the planets relative to the much larger Sun. A map of the planets shows their progression as they orbit around the Sun from Mercury's 88 days to Neptune's 165 years. Every Stargazer Map is printed on durable synthetic paper, making them waterproof, tear-resistant and tough capable of withstanding the rigors of repeated outdoor use.