... ould be like standing in a shallo bol. The atmosphere is so thick and heavy that it bends light, making the ground appear to curve upard in all directions. The planets atmosphere is 90 times heavier than Earths. Venus has sulfuric acid clouds. Its atmosphere is mostly carbon dioxide 96, nitrogen 3.5, and carbon monoxide, argon, sulfur dioxide, and ater vapor all less than 1. It takes 225 Earth days for Venus to go around the sun one time. Venus spins on its axis once every 243 Earth days, but it spins in the opposite direction of Earth. On Venus, the sun rises in the est and sets in the east. To escape Venuss gravity you have to travel at 23,300 miles per hour. Venus as identified ith the Roman goddess Aphrodite, the goddess of love and beauty. To the ancient Mayans, Venus as the patron planet of arfare called Kukulcan.3.3 EarthEarth is the third planet from the sun, hich is about 93 million miles aay. From space, Earth looks like the blue ater orld it is. About 70 of Earths surface is covered ith ater, and 97 of all that ater is in the salty oceans. Only 3 of Earths ater is freshater, the ater e drink. Earths atmosphere is a mixture of gasses that become thinner as e move aay from the planet toard space. Most of the atmosphere is nitrogen 78, oxygen 21, argon and other gases 1. Some of the oxygen in Earths atmosphere has changed over time to form ozone. Earths high ozone layer filters out the suns harmful ultraviolet rays, protecting the creatures living on the surface. But too much ozone helps trap the suns infrared rays. Infrared radiation is heat radiation. It is the armth you feel hen the sun shines on you. If too much heat is trapped in Earths atmosphere, surface temperatures ill rise. This is called the greenhouse effect and its hat makes Venus so hot. Earth goes around the sun in 365 and 14 days. Every 4 years that 14 day adds up to one hole day and e add a day to the end of February, creating a leap year. It takes only 24 hours 1 day for Earth to spin on its axis one time. Earth is covered ith mountains, volcanoes, lakes, rivers, and oceans. Most of the surface material is made of rocks high in silica, iron, and magnesium. The highest point on Earths surface is Mount Everest on the border of Nepal and China at 29,035 feet 8,850 meters. Earths average surface temperature is 45F. To escape Earths gravity you have to travel at 25,000 miles per hour. Earth has a diameter of 7,926 miles.3.4 MarsMars is the fourth planet from the sun. Its orbit is roughly 142 million miles from the sun. The planets reddish color is caused by rust iron oxide in the soil. Mars is the planet most like Earth. It takes 687 Earth days about 2 Earth years for Mars to go around the sun one time, and Mars spins on its axis at about the same speed as Earth does. It takes 24 hours and 37 minutes about 1 Earth day for Mars to rotate one time. Mars has the largest canyon Valles Marineris, and the highest volcano Olympus Mons in the solar system. If Valles Marineris ere on Earth, it ould span the United States, from Ne York on the East Coast to California on the est Coast. It is about 1,300 miles long, 310 miles ide, and about 5 miles deep. Olympus Mons is nearly 3 times higher than Mount Everest. It rises above the Martian surface more than 82 thousand feet. This giant volcanos base is the size of Missouri. There are also lots of channels on Mars, and they look like Earths river channels. Most scientists believe ater once floed on the martian surface, but ne studies suggest there may still be ater in some places on the surface. The loest surface temperature on Mars is 190F, hile the hottest temperature is 90F. To escape the gravity of Mars, you have to travel 11,200 miles per hour. Mars is about 4,212 miles in diameter. The martian atmosphere is very thin and made of carbon dioxide 95, nitrogen 3, argon and other gases 1. The polar ice ... Download