Fifty-four years ago today, on May 30, 1971 (May 7, 1971 lunar calendar), Mars' first man-made satellite, the American Mariner 9 Mars rover, was successfully launched. Image of Phobos taken by Mariner 9 On May 30, 1971, the American Mariner 9 Mars rover was successfully launched, which was the first man-made satellite of Mars. In 1971, when the American "Mariner 9" Mars rover had just traveled halfway, the entire Mars was surrounded by a large dust storm. The surface of Mars was shrouded in dust at an altitude of 70 to 80 kilometers, and it was so white that it was impossible to observe at all. Except for four craters that were vaguely visible near the equator, nothing could be seen. This huge dust storm blew continuously for half a year before it gradually subsided. This is unprecedented on Earth. It turns out that the four craters seen during the big wind and sand are actually four large volcanoes with a height of more than 25 kilometers. The largest volcano is named Olympus Volcano, 26 kilometers high and 600 kilometers in diameter. It was formed in the past 1 billion years. Located below the equator is a huge canyon, which is one of the most spectacular features on Mars --- "Mariner's Valley" Grand Canyon. The famous Mariner's Valley is 4,000 kilometers long, 300 kilometers wide, and the deepest part is 7 kilometers. The geological structure of the northern and southern hemispheres of Mars is very different. Large volcanoes, grand canyons, etc. are all in the northern hemisphere. Comments: Human curiosity prompts people to continue to explore space