Mars is the 5th planet from the sun (142 million miles from the sun). It has a reddish surface due to the amount of iron on its surface. Mars is the most similar to Earth in terms of conditions needed for life. Mars reaches 50 degrees around its equator which is suitable to support life. However the atmosphere is not thick enough to hold the oxygen we would require (This is because Mars is smaller in size and doesn't have the gravitational pull to hold in the gasses needed). The Martian atmosphere is mostly carbon dioxide with traces of oxygen. Mars on the whole is much colder than Earth (Average temperature is about -81 degrees) so any water Mars possesses is trapped as ice. There have been signs of liquid water on Mars in the past. Mars would be the most likely planet colonized by humans in the future but we would need life support.
We have made several trips to the Martian surface. We have many photos taken from the surface so we understand Mars more than any other planet. It is believed that we will send a person to Mars in the next 50 years. However, we currently don't have the ability to return him/her because the spaceship could not carry the weight of the fuel and supplies needed to make a return trip.
Due to a longer orbit, it takes Mars about twice as long as Earth to orbit the sun. Because Mars has less mass than Earth, you would weight about two and one-half less on Mars than Earth (If you weigh 100 lbs on Earth, you'd weigh about 40 pounds on Mars). The amount of gravity is directly related to the amount of mass of a planet. Mars orbits on a tilt like Earth so there are seasons on Mars.
Martian invasions have been a popular topic in science fiction and movies. A radio announcer called Orson Wells once tricked people into thinking we were being invaded by Martians who had landed in Grover's Mills, NJ. This place is just two towns from Trenton.
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