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The Earth’s moon is 240,000 miles away. Earth’s next closest neighbor is Venus, which comes as near as 24 million miles. After the moon and Venus, Mars is our next closest neighbor at 34 million miles away—though when Mars and Earth are at the opposite sides of their orbits around the sun, they are separated by 249 million miles.

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If you were driving 60 mph in a car, it would take 271 years, 221 days to get to Mars from Earth.

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The atmosphere (mostly made up of carbon dioxide) on Mars is so thin that water cannot exist in liquid form—it can exist only as water vapor or ice. Liquid water is considered for many scientists to be the “holy grail” of Mars.

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No human could survive the low pressure of Mars. If you went to Mars without an appropriate space suit, the oxygen in your blood would literally turn into bubbles, causing immediate death.

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Mars lacks an ozone layer; therefore, the surface of Mars is bathed in a lethal dose of radiation every time the sun rises.