The Crazy Hammer They're Sending to Mars

It looks like a tiny metal torpedo.

An artist's rendering of the InSight lander, which is set for a March launch to Mars. (NASA / JPL)

Space missions evoke some of the biggest questions humans can ask. How did we get here? Are we alone in the universe? You know, the usuals. But to even begin to answer these questions, scientists have to piece together the tiniest details, by making unbelievably precise measurements with crazy-imaginative technologies.

That equipment doesn’t always get the attention it deserves. Take, for instance, the array of tools that’s heading to Mars with the InSight lander in March. There’s a multi-sensor seismometer that will detect marsquakes in six directions and across a spectrum of frequencies. There’s a magnetometer and weather station to assess environmental conditions that might otherwise muck up the seismic data.

And then there’s this heat-flow probe.


This is a device that’s really best appreciated when described by Bruce Banerdt, the principal investigator of the InSight mission. “Oh, the heat flow probe,” Banerdt said. “It’s a mole which is about a foot-and-a-half long and an inch in diameter. It’s a little torpedo with a hammer inside. It digs into the ground about 15 feet—unless we run into a rock—and pulls a cable behind it. The cable brings electricity to the hammer, but it also has temperature sensors every few feet along that cable. So it measures the increase in temperature as you go down into the soil.”


That’s awesome. And even more awesome is that planetary scientists will be able to use that temperature data to extrapolate information about Mars’s interior. This is all part of the InSight mission’s focus on the planet’s core, a better understanding of which could help unravel some of the big mysteries about how Mars formed—and why it went from being Earth-like, with a gigantic ocean and a magnetic field, to being so cold and dry.

“There’s this giant jigsaw puzzle of understanding Mars, soup to nuts, and there’s a whole giant section of that puzzle that’s missing right now,” Banerdt said. With modest-looking tools like the heat-flow probe, we’re poised to know more than ever before about the Red Planet—and, by extension, the universe.