Mars (火星) is a planet and is the 4th closest planet to the Sun.The distances from the Sun to Mars is more than 141 million miles.Mars is the largest planet in the solar system(太阳系),which makes Mars the 2nd smallest planet in the solar system.Mars is one of the four planets in the solar system that is a rocky planet.These rocky planets are called "Terrestrial(类地的) Planets".
It's not know when Mars was found and by whom as Mars has been known for a very long time,and one of the planets that can be seen from the Earth without a telescope(望远镜).
Mars's orbit轨道) around the Sun is the 4th fastest orbit of all the solar system planets.Mars is red in colour and is very cold.Not the coldest of planets in the solar system but very cold all the same.The temperature on Mars is on average 80 degrees,and can get a lot colder at times.
At times in the summer near the Mars the temperature can reach 70 degrees.You may think it's warm enough to live;however,the atmosphere(大气层)2 over 95%.Mars orbits the Sun in 687 days,which means 1 Earth year on Mars is 687 days.