In Interstellar (2014), the crew members visited the second planet and found Mann. Soon after finding Mann, they discover that he has lied about the data. And then he tried to kill Cooper as he decides to leave to Earth.

Why did Mann try to kill Cooper?

  • It wasn't just to see a human face, it was to be saved from this planet where he was otherwise going to die alone.
    – Napoleon Wilson
    Commented Nov 16, 2014 at 12:50
  • @NapoleonWilson please tell me why this question does not deserve to live? Your question asks WHAT, my question covers the WHAT and asks WHY. Please let this question stay...
    – Cool_Coder
    Commented Nov 16, 2014 at 13:31
  • The other question asks and answered why Mann acted the way he did. Does this not cover your question? It might not cover your third point, but that isn't too related to the rest of your questions anyway and might have been better asked as a separate question.
    – Napoleon Wilson
    Commented Nov 16, 2014 at 13:37

4 Answers 4


First of all, we have to remember that Mann was a coward. Upon arriving on his planet, he realized it was uninhabitable but didn't want to die alone, and as such sent out a beacon to say he had found a Goldilocks habitat, so a rescue mission would be launched to find him.

Cooper, believing that they had found a suitable habitat for colonization (based on Mann's lies) was determined to take the shuttle through Gargantua and back to Earth. For all intents and purposes, at this point they believed the mission goals to have succeeded.

Cooper was going to leave them on the planet and return home.

However, Mann was lying about the planets habitability: it was, in-fact, uninhabitable. Mann was acting in self-preservation, and his options were either to somehow gain Coopers trust, assume the pair of them could overrule or overpower the rest of the crew, and return to Earth having failed the mission: or, to kill Cooper when he is vulvernable and unsuspecting. His plan from here is largely undisclosed, and he was possibly only acting spur of the moment, killing Cooper when the opportunity arose to stop him abandoning the remaining crew on an inhospitable planet.

Because Mann lies, it is unclear whether he intends to return to Earth alone in the shuttle, or (as he broadcasts to the crew) to "complete the mission" and find the last hospitable planet to start a colony. His cowardice would indicate the former, however.

Basically, cooper was going to leave the crew abandoned, and Mann saw the opportunity to eliminate him. I don't think this was premeditated, but when Coop asked Mann to escort Coop to the monitor stations, the opportunity was too good to pass up.

  • 14
    I will say, bravo to Nolan and the marketing team for not showing Mann and some other characters in the trailers leading up to the movie, thus making the reveal a complete surprise.
    – MattD
    Commented Nov 10, 2014 at 19:14
  • 5
    Why wouldn't Dr. Mann simply admit to lying once they had landed? At that point they would all want to leave the planet, and he could go with them. Surely they wouldn't leave him there to die out of spite?
    – Strigoides
    Commented Dec 11, 2014 at 7:17
  • 3
    Small correction: it was never part of the original mission to use Gargantua to get back to Earth. Gargantua is the black hole. It's the worm hole that's used to get to/from Earth.
    – 16807
    Commented May 30, 2015 at 1:56
  • 2
    @16807, wherein is anything stated contrary to this? Commented May 31, 2015 at 11:54
  • 4
    @JohnSmithOptional: "Cooper, believing that they had found a suitable habitat for colonization (based on Mann's lies) was determined to take the shuttle through Gargantua and back to Earth."
    – Kevin
    Commented Jul 1, 2015 at 20:01

Dr Mann's motivation is survival. He knew no one would save him if he was on a useless planet, so he activated the beacon to get help to come.

His reasons for trying to kill his rescuers, either by straight up murder or abandoning them on the dead planet is to protect his pride. He doesn't want people to know he wasted time and potentially millions of lives on earth by getting the only hope of humanity's survival distracted.

One of the key plot points is the juxtaposition of Mann and Cooper. Cooper being reluctant to go but willing to die for the betterment of humanity and Mann being eager to go but unwilling to die even at significant cost to humanity.


Because Cooper wanted to go back to earth once he realised that they weren't meant to save earth, but save mankind from extinction.

Mann realised this and wanted to stop him as he thought there was no hope for mankind on earth. I think he even mentioned this in the fight scene once. I need to see it again to confirm though.


if mann would have been sane, and just joined the crew back to earth, then TARS would not have been able to collect the quantum gravity data from the blackhole.. and cooper would never have communicated with murph, and plan A would never have succeeded and humanity would have died. Also since the first half of the movie happened, and Cooper had communicated through time using gravity, he was part of a closed time loop.. hence Mann had to behave the way he did :)

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