The "Pi in the Sky" math challenge gives students a chance to take part in recent discoveries and upcoming celestial events, all while using math and pi just like NASA scientists and engineers. In this problem from the ninth set, students use the mathematical constant pi to calculate the volume and density of Mars' liquid core.



Dome-covered seismometer sits on the surface of Mars while clouds pass overhead.

Clouds drift over the dome-covered seismometer, known as SEIS, belonging to NASA's InSight lander, on Mars. Credit: NASA/JPL-Caltech. | › Full image and caption

Core Conundrum

Since 2018, the InSight lander has studied the interior of Mars by measuring vibrations from marsquakes and the “wobble” of the planet as it rotates on its axis. Through careful analysis of the data returned from InSight, scientists were able to measure the size of Mars’ liquid core for the first time and estimate its density. In Core Conundrum, students use pi to do some of the same calculations, determining the volume and density of the Red Planet’s core and comparing it to that of Earth’s core.


Core Conundrum

The InSight Mars lander is equipped with several tools to help scientists learn more about the interior of the Red Planet, including a seismometer that detects marsquakes. By measuring the vibrations that travel across the surface of Mars and through its interior layers, scientists were able to accurately measure the size of Mars’ liquid core and estimate its density. Knowing the size and density of Mars' core will help us learn more about how the planet formed, how its magnetic field developed, and what materials make up the core, which will ultimately lead to a better understanding of how Earth and other planets form.

If Mars' core has a mass of 1.54 x 1023 kg and a radius of 1,830 km, as measured by InSight, what is the density of the core?

How does that compare to the density of Earth’s core, which ranges from 10 to 13 g/cm3?

What does that tell us about the makeup of Mars’ core?

› Learn more about the InSight lander

The InSight lander is shown on the surface of Mars, where circular lines radiate out from a central point. The interior of Mars is shown with lines flowing left and right from the same central point and extending from the crust into Mars’ mantle down to its large central core. In the background, a cutaway shows the interior of Earth with more interior layers and a smaller core.

Image credit: NASA/JPL-Caltech | + Expand image


Illustrated answer key for the Core Conundrum problem

Image credit: NASA/JPL-Caltech | + Expand image

Download text-only answer key (doc)



Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge

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