THE HISTORY OF MARS Ancient civilizations were fascinated by special stars that moved slowly across the sky over days weeks and months The ancient Greeks named them planetes meaning wanderer The five planets that you can see with the naked eye without a telescope were named for their gods The Greeks named them Hermes Aphrodite Ares Zeus and Cronus However we are more familiar with their Roman names Mercury Venus Mars Jupiter and Saturn Looking for Life Although Mars is not the brightest of the planets in the night sky it stands out because of its color On a clear night Mars appears as a bright star but its orangey-red color led the ancient Greeks and Romans to name it after their god of war because it was the color of blood It is also called the red planet due to its color Italian astronomer Galileo Galilei 1564 1642 was the first person to look at Mars through a telescope although the telescope’s low power meant that he could not see any detail As telescopes became bigger and more powerful bright and dark patches on Mars’s surface were seen including bright white polar caps It was then that astronomers noticed that Mars was similar to Earth in many ways The telescope was invented in 1608 but Galileo first used it for astronomy in 1609 He studied the moon and discovered Jupiter’s moons 6
Mars canyon In the late 1800s another Italian astronomer Giovanni Schiaparelli 1835 1910 claimed to see long dark lines on Mars through his telescope People started to believe these lines were canals dug by aliens living on Mars They believed the aliens used the canals to bring water from the polar caps We now know that the lines were an optical illusion Learning More About Mars It was not until the Space Age that people were able to see Mars close up from space probes and landers While much of the planet is covered with craters other parts contain some of the greatest wonders of the solar system The first probe to orbit Mars was Mariner 9 It journeyed to Mars in 1971 and discovered giant volcanoes such as Olympus Mons that are much bigger than any on Earth Olympus Mons rises to a height of nearly 13 6 miles 22 km which is around 2 5 times the height of Mount Everest Mariner 9 also discovered a canyon more than 2,500 miles 4,023 km long and up to 23,000 feet 7,000 m deep 7
WHY COLONIZE MARS With the exception of the sun if we look at the bodies of the inner solar system Mercury Venus Earth the moon and Mars each world has its own properties Some of these are listed below Look at some of the numbers and compare them to Earth’s Then imagine what it would be like for an astronaut on the surface of each body For example on the moon there is no atmosphere so you would need a spacesuit to survive there However its low gravity means that you could jump six times higher than on Earth The more different a planet is from Earth the harder it would be to survive there The Bodies of Our Inner Solar System Mercury Diameter 3,302 miles 5,314 km Gravity Earth 1 0 38 Length of day 24 hours 1 day 58 6 days Temperature 274 F to 842 F 170 C to 450 C Atmosphere None Venus Diameter 7,521 miles 12,104 km Gravity Earth 1 0 9 Length of day 24 hours 1 day 243 days Temperature 869 F 465 C Atmosphere Almost all carbon dioxide almost 100 times thicker than Earth’s 8
Earth Diameter 7,926 miles 12,756 km Gravity Earth 1 1 Length of day 24 hours 1 day 1 Temperature 128 F to 136 F Atmosphere Nitrogen oxygen and carbon dioxide Moon Diameter 2,159 miles 3,475 km Gravity Earth 1 0 16 Length of day 24 hours 1 day 29 days Temperature 279 F to 261 F 88 C to 58 C Atmosphere None Mars Diameter 4,221 miles 6,793 km Gravity Earth 1 0 38 Length of day 24 hours 1 day 1 day 7 hours Temperature 193 F to 68 F 125 C to 20 C Atmosphere Carbon dioxide 100 times thinner than Earth’s Be a Space Scientist 2 Aside from Earth which place has the best temperature for humans to survive What other feature does this world have that makes it similar to Earth 1 Find the body that has the gravity most similar to Earth’s This place would be the easiest world to walk on because our sense of balance is suited to Earth’s gravity Does this world have any other qualities that make it a great or a terrible place to live 3 When you compare the surface qualities of all the inner solar system worlds why do you think that space agencies feel Mars is the best choice of planet to colonize in the future 9
