Simcoe scientist helping NASA find signs of ancient life on Mars

·6 min read

It’s hard to say what is the more impressive feat — remotely landing a spacecraft on Mars, or a kid from Norfolk County landing a job at NASA.

Christopher Heirwegh’s unlikely trajectory took him from a Simcoe Composite School physics class to NASA’s Jet Propulsion Laboratory (JPL), where an instrument he helped design is scanning the surface of Mars for signs of ancient life.

“It’s been a very exciting past couple of weeks, starting with the anticipation leading up to the landing, followed by the joy of knowing it made it successfully,” said Heirwegh, 39, a few days after watching the Mars rover Perseverance complete its 300 million-mile journey to the Red Planet on Feb. 18.

As Perseverance floated down to the surface, Heirwegh was on the edge of his seat at his home in Pasadena, Calif.

His wife, Meagan, and their six-year-old daughter, Harper, were by his side, with the rest of Heirwegh’s JPL team sharing in the suspense on a video call.

“It hit me right at that moment before landing, around the parachute phase, that things are going to come in fast, and oh boy, if this doesn’t make it, where do we go from here?” Heirwegh said.

“There was certainly some tension.”

Perseverance’s thrusters soon kicked in to start its powered descent, and a sky crane took over to gently place the rover on Mars. While mission control filled with the cheers of relieved scientists, the Heirweghs tucked into celebratory shawarma and cake.

Now that Perseverance is trundling around the Jezero crater, Heirwegh’s work has just begun.

The physicist is keeping a close eye on PIXL, a high-tech X-ray machine that has been his sole professional focus since joining NASA in 2016.

PIXL — the Planetary Instrument for X-ray Lithochemistry — is one of two instruments mounted on the lander’s robotic arm that will help answer the mission’s central question — has there been life on Mars?

About the size of a lunch box, PIXL’s job is to scan Martian rocks for trace elements that could point to the presence of ancient life, while taking what Heirwegh describes as “super close-up pictures of rock and soil textures” that could reveal microbial evidence smaller than a grain of salt.

PIXL has an X-ray tube at its heart, similar to what dentists use when photographing teeth. The scanner shoots pinpoint-sized X-ray beams into the rock, a process not unlike how artwork investigators chemically analyze paintings to detect forgeries.

“We’re looking at things that tell us what the rock is made of, where the rock might have come from, if it was exposed to water, and also if it might have potentially harboured very primitive forms of life at one time,” Heirwegh explained.

PIXL is best at finding evidence of inorganic material — heavier elements like calcium, lead and strontium — while another instrument on the rover, called SHERLOC, looks for “the building blocks of life,” lighter organic molecules like carbon, hydrogen and oxygen.

Together, they search for “biosignatures” suggestive of fossilized bacteria that may have called a Martian ocean home billions of years ago.

“Our two instruments can each produce two-dimensional elemental maps,” Heirwegh said, likening each pinpoint of data collected to the pixels on a television that combine to form a clear picture.

“We’re hoping we can eventually overlay the two maps so we can really get a good idea of what the rock is all about.”

Reaching for the stars

The grandson of tobacco farmers who immigrated to Norfolk County from Belgium, Heirwegh grew up enthralled by the stars in the night sky and the vastness of space.

He never missed an episode of Star Trek: The Next Generation — “mostly just the Rodenberry years,” he clarified — and pored over images of the solar system captured by the Voyager probes.

“I found that pretty fascinating, and that kind of led me to what I do now,” he said.

Mike and Laurie Heirwegh have followed their son’s career with pride.

“Some of the stuff is way above what we understand. Christopher always keeps it as simple as possible for us,” Mike said with a laugh.

Mike, a retired pharmacist and business owner, said his “studious” and “reserved” son excelled in a science-heavy course load at Simcoe Composite School.

“Whitney, our daughter, said he had this microscope he got at Christmas and would project images up in his room and explain what was on the slides to her and her sister Danielle,” added Laurie, who owns a gift shop in Simcoe.

Four years studying undergraduate science at McMaster University in Hamilton led to a master’s in medical physics at Mac, where Heirwegh first tried his hand at X-ray technology.

He further studied X-ray fluorescence and radiation science while doing his PhD and post-doctoral fellowship in applied physics at the University of Guelph, which involved analyzing data collected by the Opportunity and Curiosity Mars rovers.

That piqued NASA’s interest, creating a rare opportunity for a Canadian to join the Jet Propulsion Lab.

“There were not too many people who were doing that,” Mike Heirwegh said. “To get a job like he’s doing in NASA, you have to be uniquely different than any American.”

The family left their house in Guelph to make a new life in America, with Meagan Heirwegh, herself an accomplished academic, putting her career on hold so her husband could follow his dream.

“She was extremely supportive of taking this step,” Heirwegh said. “That’s been a really key part of it, and something that helped me to have the courage to make such a drastic move.”

While navigating the immigration process, Heirwegh got to work calibrating PIXL years ahead of its launch on Perseverance.

Past Mars rovers have used X-ray fluorescence spectrometers, but PIXL is the first with an X-ray tube, a technological milestone Heirwegh finds “quite rewarding.”

In the months ahead, Heirwegh and his fellow scientists will analyze the trove of scientific data Perseverance will transmit across space to the Jet Propulsion Lab, while making sure their high-tech scanner stays properly calibrated.

To keep himself calibrated in what can be a high-pressure job, Heirwegh exercises every morning, and he and Meagan solve a Mensa puzzle together over breakfast.

“It’s a nice way to jump-start the physical and mental gears,” he said.

Heirwegh could not have known what the future held when he decided to leave Canada and boldly go to NASA to reach for the stars. But his parents say their son was destined to work on the Mars project.

“I think the term ‘perseverance’ is very much like Christopher,” Mike said. “He persevered to get to where he is.”

J.P. Antonacci, Local Journalism Initiative Reporter, The Hamilton Spectator