Earth may be our beloved home planet, but Mars exudes main character energy.
Earthlings have long yearned to travel to the Red Planet and check whether it harbors any kind of life. In July 1976, we used a robot to start looking: The Viking 1 spacecraft landed that month, followed by Viking 2 in September. The Viking twins started sending back photos and data from experiments designed to seek out life on Mars. One of the first lessons learned was that it’s hard to run scientific experiments from 23 million kilometers away.
On the 50th anniversary of that historic landing, we look back at the failures and successes of Mars exploration since Viking. Senior astronomy writer Lisa Grossman reports on the discoveries and setbacks that have steered the hunt for Martian life, including NASA’s revised approach of looking for habitable conditions before directly seeking evidence of life. As Grossman writes, the wealth of information we now have about the Red Planet has reinvigorated scientists’ excitement for finishing what Viking started.
The next step would be to bring samples to Earth for proper study. “The technology is either there or very close to there,” Grossman told me. “NASA has been landing stuff on Mars now for a very long time and has gotten very good at it.” The Perseverance rover, for example, has been collecting rock samples since 2021 and caching them for return to Earth.
But Congress cut funding for the Mars Sample Return mission in 2024, leaving the project at a standstill. Most of NASA’s efforts are instead being directed toward the Trump administration’s focus on sending people back to the moon. But Grossman notes that continued study of Mars is key to finding out if there really is, or ever was, life there — and to also learn what it would take to someday visit that intriguing red neighbor in person.
In this issue, we also explore life in the extreme environment of Earth’s stratosphere. The big news: Not only do microbes live 30 kilometers up, they shuttle between surface and sky and include common plant pathogens. Life on Mars, should it exist, might end up being a lot more familiar-looking than we expected.
