Mars was never “discovered” in the way a new moon or distant planet is, because it has been visible to the naked eye for as long as humans have been looking at the night sky.

Quick scoop

  • Mars has been known since ancient times; early records exist from Egyptian, Babylonian, Chinese, Greek, and Indian astronomers observing its motion in the sky.
  • Because of this, there is no single person or exact year for “when Mars was discovered” the way there is for planets like Uranus or Neptune.
  • In more modern terms, important “discovery” milestones include:
    • First telescopic observations by Galileo Galilei in 1610.
* Detailed position measurements by Tycho Brahe around the late 1500s, which enabled Kepler’s laws of planetary motion using Mars’s orbit.

* First close-up photos from space by NASA’s Mariner 4 flyby in 1965.

So, if someone asks “when was Mars discovered,” the accurate answer is: it wasn’t “discovered” at a specific time—humans have known Mars as a bright wandering star in the sky for thousands of years.