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Terraria Wiki
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Desktop/Console/Mobile/Switch/tModLoader-Only Content: This information applies only to the Desktop, Console, Mobile, Switch, and tModLoader versions of Terraria.
Martian ProbeHardmode exclusive
Martian Probe.png   Martian Probe (alarmed).png
Classic mode icon.png Classic
Expert mode icon.png Expert
Master mode icon.png Master
AI TypeMartian Probe AI
Max Life500/1000/1500
KB Resist100%
Immune toPoisonedConfused
Not to be confused with Probe or Martian Drone.

A Martian Probe scanning for players. Its green scanning beam turns red when players are detected.

The Martian Probe is a rare Hardmode, post-Golem flying enemy that can spawn anywhere in the outer two thirds of the map. It is most commonly found in the space layer. It does not fly through blocks until it spots a player. The Martian Probe initially appears with a green light. When it detects the player, the light turns red, and it attempts to escape. If allowed to, it initiates the Martian Madness event.

It is one of the few entities that can be detected by the Lifeform Analyzer or its upgrades.


  • Martian Probes spawn more frequently in the Space layer.
  • Effects that increase enemy spawn rates, such as Water Candles and Battle Potions, as well as events like a Blood Moon or Solar Eclipse, will give the Martian Probe more chances to spawn. The probe can also spawn during these events.
    • In addition to increasing the spawn rate, using a Water Candle will also nearly triple the Martian Probe's spawn chance.
  • The spawn rate of the Martian Probe is reduced significantly after Martian Madness is completed once.
  • Minions do not deliberately attack the Martian Probe, but those that deal contact damage may unintentionally kill it.
  • If the player follows the Martian Probe up to the sky until it escapes, it disappears before reaching the top of the map and the Martian Madness event will not occur.
  • Its Bestiary entry will not unlock if allowed to escape.
  • The Martian Probe has no means of attack besides contact damage. Its only purpose is to serve as a trigger for the event.
  • It will not spawn if a Martian Saucer is still alive somewhere in the world, regardless of event progress.
    • It also does not spawn during Lunar Events or if a boss is alive somewhere in the world.

      Martian Probe after it detected a player.

  • Once it detects a player it gains the ability to pass through solid blocks.
  • Homing projectiles will ignore Martian Probes.
  • Martian Probes can spawn above the maximum player height, meaning they can detect the player without being seen.


  • The BestiaryBestiary entry for the Martian Probe: "Sensing growing power on the planet, otherworldly beings send space-age technology to scan for advanced lifeforms."


  • Desktop Fixed a bug that prevented Martian Madness and other invasions from triggering when they should.
  • Desktop
    • Reduced spawn chance.
    • Can no longer spawn near the world center.
    • Can no longer spawn during events or boss fights.
    • Fixed Martian Probe detecting players above it.