Visit the Pi in the Sky 8 lesson page to explore classroom resources and downloads for the 2021 NASA Pi Day Challenge. Image credit: NASA/JPL-Caltech | + Expand image

Captured on Oct. 20, 2020, during the OSIRIS-REx mission’s Touch-And-Go (TAG) sample collection event, this series of images shows the SamCam imager’s field of view as the NASA spacecraft approached and touched asteroid Bennu’s surface. Image credit: NASA/Goddard/University of Arizona | › Full image and caption

NASA’s Perseverance Mars rover took a selfie with the Ingenuity helicopter, seen here about 13 feet (3.9 meters) from the rover on April 6, 2021. Image credit: NASA/JPL-Caltech/MSSS | + Expand image

This artist's concept shows what Deep Space Station-23, a new antenna dish capable of supporting both radio wave and laser communications, will look like when completed at the Deep Space Network's Goldstone, California, complex. Image credit: NASA/JPL-Caltech | + Expand image

Expedition 52 Flight Engineer Jack Fischer of NASA shared photos and time-lapse video of a glowing green aurora seen from his vantage point 250 miles up, aboard the International Space Station. This aurora photo was taken on June 26, 2017. Image credit: NASA | › Full image and caption

In the News

As March 14 approaches, it’s time to get ready to celebrate Pi Day! It’s the annual holiday that pays tribute to the mathematical constant pi – the number that results from dividing any circle's circumference by its diameter.

Pi Day comes around only once a year, giving us a reason to chow down on our favorite sweet and savory pies while we appreciate the mathematical marvel that helps NASA explore Earth, the solar system, and beyond. There’s no better way to observe this day than by getting students exploring space right along with NASA by doing the math in our Pi Day Challenge. Keep reading to find out how students – and you – can put their math mettle to the test and solve real problems faced by NASA scientists and engineers as they explore the cosmos!

How It Works

Dividing any circle’s circumference by its diameter gives us pi, which is often rounded to 3.14. However, pi is an irrational number, meaning its decimal representation goes on forever and never repeats. Pi has been calculated to 50 trillion digits, but NASA uses far fewer for space exploration.

Some people may think that a circle has no points. In fact, a circle does have points, and knowing what pi is and how to use it is far from pointless. Pi is used for calculating the area and circumference of circular objects and the volume of shapes like spheres and cylinders. So it's useful for everyone from farmers storing crops in silos to manufacturers of water storage tanks to people who want to find the best value when ordering a pizza. At NASA, we use pi to find the best place to touch down on Mars, study the health of Earth's coral reefs, measure the size of a ring of planetary debris light years away, and lots more.

In the United States, one format to write March 14 is 3.14, which is why we celebrate on that date. In 2009, the U.S. House of Representatives passed a resolution officially designating March 14 as Pi Day and encouraging teachers and students to celebrate the day with activities that teach students about pi. And you're in luck, because that's precisely what the NASA Pi Day Challenge is all about.

The Science Behind the 2021 NASA Pi Day Challenge

This year, the NASA Pi Day Challenge offers up four brain-ticklers that will require students to use pi to collect samples from an asteroid, fly a helicopter on Mars for the first time, find efficient ways to talk with distant spacecraft, and study the forces behind Earth's beautiful auroras. Learn more about the science and engineering behind the problems below or click the link below to jump right into the challenge. Be sure to check back on March 15 for the answers to this year’s challenge.

› Take the NASA Pi Day Challenge

› Educators, get the lesson here!

Sample Science

NASA’s OSIRIS-REx mission has flown to an asteroid and collected a sample of surface material to bring back to Earth. (It will arrive back at Earth in 2023.) The mission is designed to help scientists understand how planets form and add to what we know about near-Earth asteroids, like the one visited by OSIRIS-REx, asteroid Bennu. Launched in 2016, OSIRIS-REx began orbiting Bennu in 2018 and successfully performed its maneuver to retrieve a sample on October 20, 2020. In the Sample Science problem, students use pi to determine how much of the spacecraft's sample-collection device needs to make contact with the surface of Bennu to meet mission requirements for success.

Whirling Wonder

Joining the Perseverance rover on Mars is the first helicopter designed to fly on another planet. Named Ingenuity, the helicopter is a technology demonstration, meaning it's a test to see if a similar device could be used for a future Mars mission. To achieve the first powered flight on another planet, Ingenuity must spin its blades at a rapid rate to generate lift in Mars’ thin atmosphere. In Twirly Whirly, students use pi to compare the spin rate of Ingenuity’s blades to those of a typical helicopter on Earth.

Signal Solution

NASA uses radio signals to communicate with spacecraft across the solar system and in interstellar space. As more and more data flows between Earth and these distant spacecraft, NASA needs new technologies to improve how quickly data can be received. One such technology in development is Deep Space Optical Communications, which will use near-infrared light instead of radio waves to transmit data. Near-infrared light, with its higher frequency than radio waves, allows for more data to be transmitted per second. In Signal Solution, students can compare the efficiency of optical communication with radio communication, using pi to crunch the numbers.

Force Field

Earth’s magnetic field extends from within the planet to space, and it serves as a protective shield, blocking charged particles from the Sun. Known as the solar wind, these charged particles of helium and hydrogen race from the Sun at hundreds of miles per second. When they reach Earth, they would bombard our planet and orbiting satellites were it not for the magnetic field. Instead, they are deflected, though some particles become trapped by the field and are directed toward the poles, where they interact with the atmosphere, creating auroras. Knowing how Earth’s magnetic field shifts and how particles interact with the field can help keep satellites in safe orbits. In Force Field, students use pi to calculate how much force a hydrogen atom would experience at different points along Earth’s magnetic field.

Teach It

Pi Day is a fun and engaging way to get students thinking like NASA scientists and engineers. By solving the NASA Pi Day Challenge problems below, reading about other ways NASA uses pi, and doing the related activities, students can see first hand how math is an important part of STEM.

Pi Day Resources

• 
  Pi in the Sky Lessons

  Here's everything you need to bring the NASA Pi Day Challenge into the classroom.

  Grades 4-12

  Time Varies

• 
  NASA Pi Day Challenge

  The entire NASA Pi Day Challenge collection can be found in one, handy slideshow for students.

  Grades 4-12

  Time Varies

• 
  How Many Decimals of Pi Do We Really Need?

  While you may have memorized more than 70,000 digits of pi, world record holders, a JPL engineer explains why you really only need a tiny fraction of that for most calculations.

• 
  18 Ways NASA Uses Pi

  Whether it's sending spacecraft to other planets, driving rovers on Mars, finding out what planets are made of or how deep alien oceans are, pi takes us far at NASA. Find out how pi helps us explore space.

• 
  10 Ways to Celebrate Pi Day With NASA on March 14

  Find out what makes pi so special, how it’s used to explore space, and how you can join the celebration with resources from NASA.

• 
  Infographic: Planet Pi

  This poster shows some of the ways NASA scientists and engineers use the mathematical constant pi (3.14) and includes common pi formulas.

• 

  Mobile & Web Backgrounds

  Can't get enough pi? Download this year's NASA Pi Day Challenge graphics as mobile phone and web meeting backgrounds:

  • OSIRIS-REx: Mobile | Web
  • Mars Helicopter: Mobile | Web
  • Deep Space Network: Mobile | Web
  • Aurora: Mobile | Web
  • Solar Wind (not pictured): Mobile | Web

• 
  Pi Day: What's Going 'Round

  Tell us what you're up to this Pi Day and share your stories and photos on our showcase page.

Plus, join the conversation using the hashtag #NASAPiDayChallenge on Facebook, Twitter, and Instagram.

Related Lessons for Educators

• 
  Robotic Arm Challenge

  In this challenge, students will use a model robotic arm to move items from one location to another. They will engage in the engineering design process to design, build and operate the arm.

  Grades K-8

  Time 30 min to 1 hour

• 
  Whip Up a Moon-Like Crater

  Whip up a moon-like crater with baking ingredients as a demonstration for students.

  Grades 1-6

  Time 30 min to 1 hour

• 
  Make a Paper Mars Helicopter

  In this lesson, students build a paper helicopter, then improve the design and compare and measure performance.

  Grades 2-8

  Time 30 min to 1 hour

• 
  Speaking in Phases

  Students learn how waves are used in communication between far-away spacecraft and the Deep Space Network on Earth.

  Grades 3-8

  Time 30 min to 1 hour

• 
  Catching a Whisper from Space

  Students kinesthetically model the mathematics of how NASA communicates with spacecraft.

  Grades 4-12

  Time 1-2 hours

• 
  Collecting Light: Inverse Square Law Demo

  In this activity, students learn how light and energy are spread throughout space. The rate of change can be expressed mathematically, demonstrating why spacecraft like NASA’s Juno need so many solar panels.

  Grades 6-8

  Time under 30 min

• 
  Build a Relay Inspired by Space Communications

  In this intermediate-level programming challenge, students use microdevices along with light and mirrors to build a relay that can send information to a distant detector.

  Grades 8-12

  Time 1-2 hours

• 
  Math Rocks: A Lesson in Asteroid Dynamics

  Students use math to investigate a real-life asteroid impact.

  Grades 8-12

  Time 30 min to 1 hour

Related Activities for Students

• 
  Code a Mars Helicopter Video Game

  Create a video game that lets players explore the Red Planet with a helicopter like the one going to Mars with NASA's Perseverance rover!

  Type Project

  Subject Technology

• 
  Make a Paper Mars Helicopter

  Build a paper helicopter, then see if you can improve the design like NASA engineers did when making the first helicopter for Mars.

  Type Project

  Subject Engineering

• 
  How Does NASA Spot a Near-Earth Asteroid?

  Watch this one-minute video to find out how NASA spots and tracks asteroids that fly close to Earth.

  Type Video

  Subject Science

• 
  What's That Space Rock?

  Find out how to tell the difference between asteroids, comets, meteors, meteorites and other bodies in our solar system.

  Type Slideshow

  Subject Science

Explore More

Infographic

• Solar Wind

Facts and Figures

• Mars
• Asteroid Bennu

Missions and Instruments

• OSIRIS-REx
• Deep Space Optical Communications
• Mars Perseverance Rover
• Ingenuity Helicopter

Websites

• NASA Solar System Exploration
• NASA Mars Exploration

TAGS: Pi, Pi Day, NASA Pi Day Challenge, Math, Mars, Perseverance, Ingenuity, Mars Helicopter, OSIRIS-REx, Bennu, Asteroid, Auroras, Earth, Magnetic Field, DSOC, Light Waves, DSN, Deep Space Network, Space Communications

• 

  ABOUT THE AUTHOR

  Lyle Tavernier, Educational Technology Specialist, NASA-JPL Education Office

  Lyle Tavernier is an educational technology specialist at NASA's Jet Propulsion Laboratory. When he’s not busy working in the areas of distance learning and instructional technology, you might find him running with his dog, cooking or planning his next trip.