NASA Just Landed a Probe on Mars – Here's Why It's There

••• David McNew/Getty Images News/GettyImages

It's a big, big week for space news: NASA made another major advance in space exploration by successfully landing a spacecraft, called InSight, on Mars.

The mission to mars has been about 10 years in the making, with significant delays while scientists worked to get the recording instruments on the spacecraft just right. It was launched in May and, after months to travel, finally reached Mars on Monday. InSight was joined by two briefcase-sized satellites, called MarCO-A and MarCO-B, designed to transmit info about the landing back to earth.

So How Did They Land on Mars, Anyway?

Successfully landing any spacecraft on Mars is a tough. Not only does its atmosphere make spacecrafts turn super hot – increasing the risk of burning or heat damage – but that atmosphere is also incredibly thin. That means that any spacecraft entering won't slow down as much as it would in a more dense atmosphere, making crashes much more likely.

To land successfully, engineers equipped InSight with parachutes to slow down its trajectory. And they purposely kept InSight as light as possible (a little under 800 pounds) so the parachute could slow it down enough to prevent a disaster. Combined with the atmospheric drag – friction from the atmosphere – the spacecraft is designed to slow from 12,300 mph to 5 mph in just a few minutes.

And thankfully, it worked! Both MarsCO satellites also made it to Mars safely – the first time such satellites have made it into deep space.

FYI, if you want to test how you might have done landing the spacecraft, this minigame lets you give it a try.

Sounds Cool, Right? Here's Why They Sent It

As you might have guessed, InSight is an unmanned spacecraft (no humans on Mars yet!). And unlike some earlier spacecraft sent to Mars, it also can't move around the planet. Instead, it's there to record seismic waves – sound waves – on Mars.

Scientists already use seismic waves to study the earth – geologists use them to learn about and predict likely earthquakes, for example. And they'll apply similar principles to study Mars (and "marsquakes"). Ultimately, the info from InSight should tell scientists more about the internal makeup of Mars and learn about the structure of the planet.

In the coming months, InSight will drill into Mars' surface to start collecting data. And the mission will continue for almost two years (or a little over one Martian year), until November 24, 2020.

What Does the InSight Mission Mean for Space Exploration?

Successfully landing InSight advances scientists' examination of deep space. Not only can scientists learn about the makeup of Mars to better understand our solar system. And they'll also learn more about the formation and development of rocky plants – a group that also includes Venus and Mercury.

Overall, we're still a long way away from manned missions on Mars. But learning more about the planet's makeup and seismic activity brings us one step closer to sending to Mars.