NASA's next mission will give us InSight into Mars' interior

Of all the wonders in our solar system, there's no place beyond our own planet that's been studied more intensely than Mars. Since humans first took to the stars we've sent over 21 different spacecraft to study our rust-colored neighbor. Right now there are two rovers driving around inside of craters, and six satellites overhead. But all of this activity still isn't enough--Mars is about to get one more resident. In about a week NASA will launch a lander called InSight.