There's a vacancy at NASA, and it may have one of the greatest job titles ever conceived: planetary protection officer.

It pays well, between $124,000 and $187,000 annually. You get to work with really smart people as part of the three- to five-year appointment but don't have to manage anyone. And your work could stave off an alien invasion of Earth or, more important, protect other planets from us.

President Donald Trump has expressed bullish enthusiasm for America's space program, signing an executive order last month resurrecting the National Space Council, on hiatus since the 1990s, and gleefully discussing the prospect of sending people to Mars. His proposed budget for NASA seeks a slight funding reduction overall, though he wants to realign spending to focus on "deep space exploration rather than Earth-centric research," as The Post reported in March.

So how does the one-person Planetary Protection Office fit in with NASA's broader objectives?

The job announcement is rather dense. But Catharine Conley, the NASA scientist who has been in this role for three years, has spoken candidly about its scope and responsibilities, telling Scientific American in 2014 that her focus is to ensure that the agency's activity complies with a 50-year-old international treaty that set standards for preventing biological contamination outside of Earth and safeguarding the planet's biosphere from any alien life.

To that end, the magazine asked Conley a lot about Mars, where NASA has deployed exploratory spacecraft and robots since the mid-1970s to search for clues about the existence of water, prospects for habitability and any existence of life. The earliest missions, part of NASA's Viking program, included meticulous steps to not sully the Martian landscape, she said.

"The landers," Conley explained, "were packaged and put inside a bioshield and baked in an oven to kill all organisms - a 'full-system sterilization,' we call it. . . . We needed to protect the life-detection instruments and protect the Mars environment in case it turned out to be habitable to Earth life."

Today, rovers operate where it's believed water once existed, gathering imagery, analyzing the environment and beaming that data back to Earth. And as scientists' understanding of the Red Planet evolves, so do the questions facing those working to send people there in the coming decades.

"Will the humans be alive by the time they get to Mars?" Conley asked in 2014. "If they die on Mars, are they then contaminating the surface?" That could interfere with future research, she said.

Environmental and atmospheric samples may hold important answers, "ostensibly to seek out signs of aliens," as Business Insider's Dave Mosher writes. But sending anything from Mars back to labs here on Earth presents risk. The planetary protection officer will be instrumental in creating the tools and rules to reduce it.

"The phrase that we use," Conley told Mosher, "is 'Break the chain of contact with Mars.'"

She has not said whether she intends to reapply for the job.

By Andrew Degrandpre (c) 2017, The Washington Post