NASA's search for the next real-life guardian of the planet has brought in an ambitious cover letter sent by a fourth-grader looking for the job.

According to CNN,this week, Nasa started looking for its new planetary protection officer, someone capable of guarding the planet from "microbial contamination from other planets."

Jack Davis, a self-proclaimed "Guardian of the Galaxy" from New Jersey in USA, piqued NASA's interest, reports CNN.

"I may be nine but I think I would be a fit for the job," Jack said in the handwritten letter.

Jack went on to list his interstellar work experience.

"I have seen almost all the space and alien movies I can see," the 9-year-old explained.

He also showed he's on the case when it comes to career development.

"I have also seen the show Marvel Agents of Shield and hope to see the movie Men in Black."

Jack also described his fine motor skills and the ability to quickly learn and apply new concepts. "I'm great at video games," he said. "I am young, so I can learn to think like an Alien."

NASA replied to the letter and Jack even got a phone call from Planetary Research Director Jonathan Rall.

In the letter, they congratulated Jack on his interest and offered some extra insights about the job.

"It's about protecting Earth from tiny microbes when we bring back samples from the Moon, asteroids and Mars. It's also about protecting other planets and moons from our germs as we responsibly explore the Solar System," wrote James L. Green, director of NASA's planetary science division.

While NASA ended up not offering him the job, it wasn't an outright rejection.