Last Monday, after an almost seven-month-long, 300-million-mile journey from Earth, the InSight spacecraft survived an intense plunge through the atmosphere of Mars and successfully landed on its surface. The plucky craft – about the size of a big 1960s convertible – will study what’s going on deep inside the Red Planet, and will, ultimately, help us better understand the Earth.
InSight is the eighth NASA craft to land on the surface of Mars. Other spacecraft have been sent to orbit the planet and study it from on high. But, historically only 40 percent of missions sent by various nations to Mars have been successful. So InSight’s landing was anything but routine.
Engineers refer to the landing phase of a Mars mission as “seven minutes of terror” because the spacecraft has to perform a complex series of actions flawlessly in a very short period of time. And, because it’s so far away, the craft has to do everything automatically, with no human input or control.
But everything worked perfectly, as InSight hit the Martian atmosphere moving at over 12,000 miles per hour, and, six and a half minutes later, had slowed, using a parachute and rocket thrusters, to a gentle 5 mph for landing. Despite the huge distances involved and time since launch, InSight landed exactly where scientists had planned – a large, flat plain near the equator, devoid of big rocks, that scientists described as a parking lot or “Kansas without the corn.”
InSight is the first mission designed to look deep into the interior of the Red Planet, not its surface. Over the next few months, InSight’s robotic arm will lift two main instruments off the lander and place them on the Martian surface. Scientists have likened the process to an arcade claw game where you try to pick up a prize without dropping it … if you played the game remotely from another planet while blindfolded, with only occasional peeks at the prize to make sure you had a good grip on an irreplaceably valuable prize.
The arm will place a seismometer on the surface to listen for seismic waves caused by Marsquakes and meteorites hitting the ground. And it will set down a probe that will then burrow almost 16 feet into the Martian soil to measure heat flowing out from the interior. A third instrument will measure InSight’s position over time with great precision, allowing scientists to measure how the planet wobbles as it orbits the Sun.
The instruments were designed and built in over six countries. Although managed by NASA, InSight is an international collaboration.
InSight’s instruments will help scientists understand what’s going on deep inside Mars, whether its core is molten or not, how thick its crust is, and whether Mars was born from the same planet-forming material as the Earth and Moon. InSight will help answer questions about how rocky planets, including Earth, form and evolve.
Studying Mars gives us something to compare Earth to, and that can teach us a lot about our home planet. We need a better understanding of our planet’s past and present in order to more accurately predict its future.
Previous missions have suggested that Mars once had vast amounts of liquid water on its surface, but lost its magnetic field and most of its atmosphere, causing the water to evaporate. Understanding the interior of the Red Planet may help us understand why these mysterious losses happened, and what happened to the water — and any life that may have evolved in it. And it can help us know if something similar could happen here on Earth.
But I think there is another, perhaps more fundamental, reason to study Mars – to expand our knowledge about the universe in which we live and our place in it. Humans, as a species, are extraordinarily curious. We’re always looking around the corner or under a rock. We are explorers, who venture into the unknown. Planetary missions like InSight fill that very human need to learn and know more.
What InSight teaches us about Mars will influence plans to send humans to the Red Planet. That will be exciting, as mankind takes our first tentative steps away from home and out into the cosmos. But going to Mars is not a panacea that allows us to ignore environmental and social problems on Earth. We must address those. But we can, at the same time, also look outward to Mars and beyond.
InSight gives us a broader perspective on our home planet, shows us nations peacefully working together, and will expand what we know about life, our solar system, and our universe. Good luck, InSight. I can’t wait to see what you discover.