During a manned mission to Mars, Astronaut Mark Watney is presumed dead after a fierce storm and left behind by his crew. But Watney has survived and finds himself stranded and alone on the hostile planet. With only meager supplies, he must draw upon his ingenuity, wit and spirit to subsist and find a way to signal to Earth that he is alive. If Mark Watney uses infrared waves (λ approximately 10-5 meters) to try and contact NASA, how long, in minutes, will it take for his message to reach Earth from Mars?

The answer is 12.5 but I don't know how to get that

  • Hi there! Can you post the whole problem? It seems it's missing the distance value Reyn commented about 3 years ago
  • 225 million kilometers from Earth to Mars Angelle commented about 3 years ago