How the Earth Was Born: Next NASA Mars Mission Could Deliver New Clues

This month, the Curiosity rover celebrated its fifth anniversary on Mars by puttering around the Gale Crater and doing more science. Its nearest neighbor, Opportunity, is on the other side of the planet. But next year, the pair of beloved rovers will receive a new kind of companion, a lander that will peer deep below the planet's surface in hopes of understanding how it formed.

The new spacecraft, called InSight, is scheduled to launch in May or June and land just after Thanksgiving 2018 near the planet's equator. Once there, it will begin two years of science work.

So far, spacecraft visiting Mars have explored its surface. But InSight—which is short for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport—will focus on the interior of Mars for a compelling reason: so we can learn more not only about the Red Planet but also about our own.

Because Mars hasn't been as geologically active as Earth (think plate tectonics, which reshapes Earth's surface and recycles its rock), the interior of Mars should still contain intact traces of the planet's earliest history. InSight will take a range of measurements designed to tell scientists about the size and composition of the three layers of Mars—crust, mantle and core—and about how much the interior of Mars is moving around.

For all that science, InSight will carry just three main pieces of equipment. A heat probe will hammer itself at least 10 feet below the surface to measure how much energy is rising up through Mars. A seismometer will track so-called "Marsquakes," tiny vibrations that scientists have yet to measure but that could reveal what the inside of Mars is made of. And by sending radio waves between Earth and Mars, InSight will help determine how much the planet wobbles in its orbit, which could point to the structure of its core.

All of that information about the interior of Mars should help scientists figure out how the planet formed, about the same time Earth did 4.6 billion years ago, from a vast cloud of gas and dust. Astronomers already know the gist of this story. This material began to clump together, with the largest clumps eventually gathering enough material via gravity to become planets. All these collisions also created heat, melting the center of what became each planet and causing their ingredients to form layers based on density.

But even though all our neighboring planets are made of about the same mix of stuff, they've formed different layer structures. NASA hopes that obtaining this better picture of the layers of Mars will help solve the mystery of how and why Earth and Mars ended up so different, despite their similar beginnings.