MARS IS FULL OF MYSTERIES THAT WE COULD SOLVE

Iwas born squarely in the middle years of the Apollo missions to the moon. As a child, it seemed then like it would be no time at all until humans would be treading the sands of Mars. When America’s Viking robotic landers touched down on the surface of Mars in 1976 and sent back photos of the desolate surface, that moment seemed ever closer. Perhaps, I pondered, I’d be the right age to fly there myself.

A decade later, I felt as jaded as any teen, but I had extra reasons. Humans were doing amazing things in Earth orbit, with space shuttles and space stations — but Mars seemed further away than ever.

In the long run, however, this delay has turned out to be very positive. In recent decades, humans have learned more than we ever imagined about how life can cling on tenaciously in extreme, hostile places here on Earth. Clustered around hot water vents in the depths of the ocean, some life does not need the sun at all. Beneath half a mile of ice in the Antarctic, chilly lakes isolated from the rest of Earth for many thousands of years teem with life. This means that when we do venture to Mars in person, we know much more about what to look for. Most importantly, we know how easy it would be to inadvertently bring life to Mars with us on our explorations, contaminating the surface forever.

So thank goodness humans didn’t go to Mars in the 1980s. We’d probably have found life — the bacteria we brought with us — and nothing else. Instead, robotic orbiters and landers, sterilized to the highest possible levels, have been our eyes and ears on Mars. A number of rovers have trundled around for years, exploring mountain ranges and craters, finding exciting evidence of Martian lakes and oceans from billions of years ago. At the same time, orbiting spacecraft — many carrying powerful instruments built right here in San Diego — have mapped the surface in unprecedented detail. Both detailed and wider pictures of Mars have been built up without sending humans there at all. We can explore new worlds from our laptops.

Feb. 18 brought another exciting development. In a risky maneuver that had to be done completely automatically — radio signals take too long to travel from Earth to Mars to be helpful — an enormous new rover, the size of a car, was gently placed on the Martian surface, in an ancient lakebed once fed by a river delta, nestled within a crater. It’s an area of big boulders and steep cliffs, so the landing had to be made with pinpoint accuracy. Screaming into the atmosphere under a protective shell, the rover was slowed to a soft touchdown on the Martian surface by an ingenious process named the skycrane maneuver. Part of the spacecraft fires rocket thrusters to hover while lowering the rover on wires.

The rover, named Perseverance, has an ambitious challenge ahead. It’s going to start collecting samples for a return to Earth someday. The rover can’t return them, and the spacecraft that will has yet to be developed. But in a mood of optimism, the rocks will be accumulated for this future event.

Perseverance will mostly be looking for evidence of life — more likely in this region to be ancient remains of longdead microbes. But who knows? Mars is full of mysteries. It is hard to imagine the effect on the human imagination if we learn that life has not only existed on our planet, but also elsewhere.

The rover even carries a tiny helicopter aboard that, drone-like, will fly across the surface. Humans are about to test fly an aerial vehicle on another planet. The inner child in me is excited beyond imagination.

In August 2019, I was fortunate enough to be at NASA’S Jet Propulsion Laboratory complex and saw Perseverance being packed up for launch. When it landed, I happened to be on the Sentinel-arlington volcanic field in Arizona — a place of jagged red rocks and soil that looks very much like Mars. The cell phone I carried with me had more computing power than anything in the Apollo era, and is a direct result of space program technology. In a moment earlier generations would have thought impossible, I could stand in that remote Martian-looking landscape and watch images come back from the rover on the real Mars.

It was surreal. I looked at little blades of grass struggling to live in this desert, and imagined microbes on Mars trying to do the same. I hope Perseverance finds them.