Humans will most likely walk on the Moon again before they walk on another planet, and the first different planet could plausibly be Mars sometime in the 2030s or 2040s, though that is still highly uncertain. Current reporting around NASA’s Artemis program shows the Moon remains the near-term stepping stone, with plans to keep building toward a crewed lunar landing in the coming years.

What the timeline looks like

  • Moon first: Artemis II recently marked a major crewed lunar-flight milestone, and NASA’s next steps are aimed at landing astronauts on the Moon and developing longer-duration deep-space capability.
  • Mars later: A human Mars landing is a much bigger leap because of distance, radiation, life-support, and entry-descent-landing challenges, so it is generally expected to come after a sustained Moon program.
  • Other planets are far less likely soon: Walking on Venus, Jupiter, or Saturn’s moons is not a near-term human goal, and Mars is the only planet that is even remotely in the realistic discussion for this century.

Best estimate

A careful answer is: not before the 2030s, and more realistically the 2040s or beyond for the first humans walking on a different planet, with Mars the leading candidate.

Why the Moon matters

NASA and other space agencies are using lunar missions to test the hardware and health impacts needed for deeper travel, because the Moon is close enough to support learning while still being harsh enough to matter for Mars preparation. That is why “walking on a different planet” is probably a question of Mars after the Moon, not a direct jump.

Bottom line

If you mean a planet other than Earth , the most likely answer is Mars, and the most realistic window is probably decades from now , not years.