Mariner 9 entered orbit around Mars, making history as the first spacecraft to successfully orbit another planet. Launched on May 30, 1971, it traveled for nearly 11 months, covering a distance of 650 million kilometers (about 400 million miles). Upon arrival in November, Mariner 9 overcame initial challenges due to a planet-wide dust storm, which had enveloped the Martian surface. However, as conditions improved, the spacecraft began transmitting its findings back to Earth.

The Mariner 9 mission provided pivotal data about the Martian terrain, environment, and climate. It sent back over 7,000 images, showcasing features such as the enormous volcano Olympus Mons and the vast canyon Valles Marineris. These discoveries fundamentally altered the scientific community's understanding of Mars, leading to questions about its geological history and potential for past life. The successful transmission of data continued until early 1972, significantly contributing to the body of exploration aimed at understanding Mars.

Mariner 9's mission represented a major leap for planetary exploration, inspiring future missions and ongoing interest in Mars, culminating in today's advanced rovers and orbital missions. The data collected helped lay the groundwork for subsequent missions, fostering a new era of Martian exploration that has only accelerated in the years since.