Teachable Moments | January 24, 2022
Reflecting On Greenland’s Melting Glaciers as OMG Mission Concludes
Explore how the OMG mission discovered more about what's behind one of the largest contributors to global sea level rise. Plus, learn what it means for communities around the world and how to get students engaged.
After six years investigating the effects of warming oceans on Greenland's ice sheet, the Oceans Melting Greenland, or OMG, mission has concluded. This airborne and seaborne mission studied how our oceans are warming and determined that ocean water is melting Greenland’s glaciers as much as warm air is melting them from above.
Read on to learn more about how OMG accomplished its goals and the implications of what we learned. Then, explore educational resources to engage students in the science of this eye-opening mission.
Why It's Important
Global sea level rise is one of the major environmental challenges of the 21st century. As oceans rise, water encroaches on land, affecting populations that live along shorelines. Around the world – including U.S. regions along the Gulf of Mexico and Eastern Seaboard and in Alaska – residents are feeling the impact of rising seas. Additionally, freshwater supplies are being threatened by encroaching saltwater from rising seas.
Sea level rise is mostly caused by melting land ice (primarily glaciers), which adds water to the ocean, as well as thermal expansion, the increase in volume that occurs when water heats up. Both ice melt and thermal expansion result from rising global average temperatures on land and in the sea – one facet of climate change.
Greenland’s melting glaciers contribute more freshwater to sea level rise than any other source, which is why the OMG mission set out to better understand the mechanisms behind this melting.
How We Did It
The OMG mission used a variety of instruments onboard airplanes and ships to map the ocean floor, measure the behemoth Greenland glaciers, and track nearby water temperature patterns.
Early on, the mission team created a map of the ocean floor, known as a bathymetric map, by combining multibeam sonar surveys taken from ships and gravity measurements taken from airplanes. Interactions among glaciers and warming seas are highly dependent on the geometry of the ocean floor. For example, continental shelf troughs carved by glaciers allow pathways for water to interact with glacial ice. So understanding Greenland's local bathymetry was crucial to OMG's mission.
To locate the edges of Greenland's glaciers and measure their heights, the mission used a radar instrument known as the Glacier and Ice Surface Topography Interferometer. Every spring during the six-year OMG mission, the radar was deployed on NASA’s Gulfstream III airplane that flew numerous paths over Greenland’s more than 220 glaciers. Data from the instrument allowed scientists to determine how the thickness and area of the glaciers are changing over time.
Finally, to measure ocean temperature and salinity patterns, scientists deployed numerous cylindrical probes. These probes dropped from an airplane and fell through the water, taking measurements from the surface all the way to the ocean floor. Each probe relayed its information back to computers onboard the plane where ocean temperatures and salinity were mapped. Then, scientists took this data back to their laboratories and analyzed it for trends, determining temperature variations and circulation patterns.
What We Discovered
Prior to the OMG mission, scientists knew that warming air melted glaciers from above, like an ice cube on a hot day. However, glaciers also flow toward the ocean and break off into icebergs in a process called calving. Scientists had the suspicion that warmer ocean waters were melting the glaciers from below, causing them to break off more icebergs and add to rising seas. It wasn’t until they acquired the data from OMG, that they discovered the grim truth: Glaciers are melting from above and below, and warming oceans are having a significant effect on glacial melt.
What this means for our Earth's climate is that as we continue burning fossil fuels and contributing to greenhouse gas accumulation, the oceans, which store more than 90% of the heat that is trapped by greenhouse gases, will continue to warm, causing glaciers to melt faster than ever. As warming ocean water moves against glaciers, it eats away at their base, causing the ice above to break off. In other words, calving rates increase and sea level rises even faster.
Our oceans control our climate and affect our everyday lives, whether or not we live near them. With the pace of the melt increasing, our shorelines and nearby communities will be in trouble sooner than previously expected. And it’s not just the beaches that will be affected. If Greenland’s glaciers all melt, global sea levels will rise by over 24 feet (7.4 meters), bringing dramatic change to the landscapes of major cities around the world.
› Read more about OMG’s findings and how scientists are continuing their research through ongoing initiatives and projects.
Check out these resources to bring the real-life STEM behind the mission into your teaching. With lessons for educators and student projects, engage students in learning about the OMG mission and NASA climate science.
Melting Ice Experiment
Students make predictions and observations about how ice will melt in different conditions then compare their predictions to results as they make connections to melting glaciers.
Time 30-60 mins
What's Causing Sea-Level Rise? Land Ice Vs. Sea Ice
Students learn the difference between land ice and sea ice and make a model to see how the melting of each impacts global sea level.
Time 30-60 mins
Lessons in Sea-Level Rise
What is sea-level rise and how does it affect us? This "Teachable Moment" looks at the science behind sea-level rise and offers lessons and tools for teaching students about this important climate topic.
Time 30-60 mins
Collection: Climate Change Lessons for Educators
Explore a collection of standards-aligned STEM lessons for students that get them investigating climate change along with NASA.
How Melting Ice Causes Sea Level Rise
Learn the difference between land ice and sea ice, then do an experiment to see how the melting of each contributes to global sea level rise.
Time 30-60 mins
Collection: Climate Change Activities for Students
Learn about climate change and its impacts with these projects, videos, and slideshows for students.
NASA Greenland Mission Completes Six Years of Mapping Unknown Terrain
To learn how ocean water is melting glaciers, NASA’s Oceans Melting Greenland mission extensively surveyed the coastline of the world’s largest island.
- NASA Climate Change
- NASA Earth Observatory
- NASA Climate Kids
- OMG Mission Website
- NASA Sea Level Change
- NASA Cambio Climático en Español
Facts & Figures
- Climate articles from NASA
- Ask NASA Climate
- NASA People - Josh Willis, Principal Investigator, Oceans Melting Greenland
- NASA People - Earth
TAGS: Teachable Moment, Climate, Earth Science, Glaciers, Greenland, Ice, Sea Level Rise, Teachers, Educators, Parents, Lessons, Missions, Earth, Climate TM
Teachable Moments | October 3, 2017
Gravitational Waves Detected for the First Time
Update – Oct. 3, 2017: Researchers Kip Thorne and Barry Barish of Caltech and Rainer Weiss of MIT have been awarded the 2017 Nobel Prize in Physics for their “decisive contributions to the LIGO detector and the observation of gravitational waves.”
Thorne, Barish and Weiss played key roles in making the LIGO project a reality through their research, leadership and development of technology to detect gravitational waves.
In a statement to Caltech, Thorne said the prize also belongs to the more than 1,000 scientists and engineers around the world who play a part on LIGO, the result of a long-term partnership between Caltech, MIT and the National Science Foundation.
› Read the Caltech press release
This story was originally published on March 23, 2016.
In the News
A century ago, Albert Einstein theorized that when objects move through space they create waves in spacetime around them. These gravitational waves move outward, like ripples from a stone moving across the surface of a pond. Little did he know that 1.3 billion years earlier, two massive black holes collided. The collision released massive amounts of energy in a fraction of a second (about 50 times as luminous as all the stars in the visible universe combined) and sent gravitational waves in all directions. On September 14, 2015 those waves reached Earth and were detected by researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO).
Why It's Important
Einstein published the Theory of General Relativity in 1915. In it, he predicted the existence of gravitational waves, which had never been directly detected until now. In 1974, physicists discovered that two neutron stars orbiting each other were getting closer in a way that matched Einstein’s predictions. But it wasn’t until 2015, when LIGO’s instruments were upgraded and became more sensitive, that they were able to detect the presence of actual gravitational waves, confirming the last important piece of Einstein’s theory.
It's also important because gravitational waves carry information about their inception and about the fundamental properties of gravity that can’t be seen through observations of the electromagnetic spectrum. Thanks to LIGO’s discovery, a new field of science has been born: gravitational wave astronomy.
How They Did It
LIGO consists of facilities in Washington and Louisiana. Each observatory uses a laser beam that is split and sent down 2.5-mile (4-kilometer) long tubes. The laser beams precisely indicate the distance between mirrors placed at the ends of each tube. When a gravitational wave passes by, the mirrors move a tiny amount, which changes the distance between them. LIGO is so sensitive that it can detect a change smaller than 1/10,000 the width of a proton (10-19 meter). Having two observatories placed a great distance apart allows researchers to approximate the direction the waves are coming from and confirm that the signal is coming from space rather than something nearby (such as a heavy truck or an earthquake).
Creating a model that demonstrates gravitational waves traveling through spacetime is as simple as making a gelatin universe!
Middle school students can develop a model that shows gravitational waves traveling through spacetime while working toward the following Next Generation Science Standard:
- MS-PS4-2 - Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.
- Gravitational waves news, videos and resources
- Laser Interferometer Gravitational-Wave Observatory (LIGO) Website
TAGS: Gravitational Waves, Teachable Moment, LIGO, Black Holes, Einstein
Teachable Moments | January 13, 2016
Cruising to Jupiter: A Powerful Math Lesson
In the News
NASA’s Juno mission, the first solar-powered mission to Jupiter, has become the farthest solar-powered spacecraft ever! Juno, and its eight science instruments designed to study the interior of Jupiter, has passed the mark previously held by the European Space Agency’s Rosetta mission and reached a distance of 5.3 astronomical units from the sun (an astronomical unit is equal to the average distance between Earth and the sun – about 149.6 million kilometers). Using only power from the sun, Juno will complete the five-year trip to Jupiter in July 2016 and begin studying the solar system’s most massive world in an attempt to better understand the origins of the planet, and in turn, our solar system.
What Made It Possible
Just as a bright source of light dims as you move away from it, sunlight becomes less intense the farther a spacecraft travels from the sun, limiting the amount of power that can be generated using solar cells. Previous missions that visited Jupiter, like Galileo, Voyager 1 and Voyager 2, couldn’t use solar power and instead used radioisotope thermoelectric generators (RTGs) to supply power.
Advances in solar panel efficiency along with improvements in the way spacecraft and their instruments use power have recently made solar power a viable option for spacecraft heading as far as Jupiter – though going beyond will require further technological advances.
Engineers designed Juno with three massive solar panels, each nearly 30 feet long. Combined, they provide Juno with 49.7 m2 of active solar cells. Once it reaches Jupiter, Juno will generate more than 400 watts of power, which may not sound like a lot, but it’s an impressive feat at so great a distance. For comparison, Juno’s solar panels can generate about 14 kilowatts near Earth.
Juno's record-setting achievement translates into a powerful lesson in exponents.
Middle school students and other students working with exponents will find challenging, real-world applications related to the work being done here at NASA while addressing four Common Core Math standards:
- Grade 6: Expressions and Equations A.1 - "Write and evaluate numerical expressions involving whole-number exponents."
- Grade 6: Expressions and Equations A.2 - "Write, read, and evaluate expressions in which letters stand for numbers."
- Grade 6: Expressions and Equations A.2.C - "Evaluate expressions at specific values of their variables. Include expressions that arise from formulas used in real-world problems. Perform arithmetic operations, including those involving whole-number exponents, in the conventional order when there are no parentheses to specify a particular order (Order of Operations)."
- Grade 8: Expressions and Equations A.1 - "Know and apply the properties of integer exponents to generate equivalent numerical expressions. For example, 32 × 3-5 = 3-3 = 1/33 = 1/27."
- Juno mission website - News, resources and updates on NASA's mission to Jupiter.
- Eyes on the Solar System - Take a virtual journey to Jupiter with Juno (scroll to "Solar System Tours" and click on Juno).
- To Jupiter with JunoCam! - Find out how classrooms can participate in the Juno mission to Jupiter using the spacecraft's on-board educational camera.
- Infographic: Solar Power Explorers - This graphic shows how NASA’s Juno mission to Jupiter became the most distant solar-powered explorer and influenced the future of space exploration powered by the sun.
TAGS: Juno, Jupiter, Exponents, Math, Lesson, Activity, Teachable Moment
Teachable Moments | July 16, 2015
NASA's New Horizons Mission Flies by Pluto
In the News
We visited Pluto!
On July 14, 2015 at 4:49 a.m. PDT, NASA's New Horizons spacecraft sped past Pluto -- a destination that took nearly nine and a half years to reach -- and collected scientific data along with images of the dwarf planet.
Pluto, famous for once being the ninth planet, was reclassified as a dwarf planet in 2006 after new information emerged about the outer reaches of our solar system. Worlds similar to Pluto were discovered in the region of our solar system known as the Kuiper Belt. The Kuiper Belt --named for astronomer Gerard Kuiper --is a doughnut-shaped area beyond the orbit of Neptune that is home to Pluto, other dwarf planets such as Eris, Makemake, and Haumaea, as well as hundreds of thousands of other large icy bodies, and perhaps trillions of comets orbiting our sun. Over the next several years, the New Horizons spacecraft is expected to visit one to two more Kuiper Belt objects.
Even though it will take 16 months for New Horizons to return all the Pluto science data to Earth, we have already made some interesting and important discoveries about Pluto.
Why It's Important
Through careful measurements of new images, scientists have determined that Pluto is actually larger than previously thought: 2,370 kilometers in diameter. This is important information for scientists because it helps them understand the composition of Pluto. Because of the orbital interactions between Pluto and its moon Charon, Pluto’s mass is well known and understood. Having a more precise diameter gives scientists the ability to more accurately calculate the average density. A greater diameter means Pluto’s density is less than we thought. If you do the math, you’ll see that Pluto’s calculated density dropped from 2,051 kg/m3 to 1,879 kg/m3 with this new finding. Most rock has a density between 2000-3000 kg/m3 and ice at very cold temperatures has a density of 927 kg/m3, so we can conclude that Pluto is a bit more icy than previously believed. In addition to helping scientists calculate the density of Pluto, this measurement confirms Pluto as the largest known object in the Kuiper Belt!
We’ve provided some math problems (and answers) for you to use in the classroom. They’re a great way to provide students with real-world examples of how the math they’re learning in class is used by scientists. There are also some additional resources below that you can use to integrate the Pluto flyby into your lessons, or use the flyby as a lesson opener!
Pluto Math Problems
- Find the radius(r) of Pluto.
2,370 kilometers ÷ 2 = 1,185 km
- Find the circumference of Pluto.
C = 2 π r = 7,446 km
- Find the surface area of Pluto.
SA = 4 π r2 = 17,646,012 km2
- Find the volume of Pluto.
4/3 π r3 = 6,970,174,651 km3
- Find the density of Pluto in kg/m3.
Pluto mass = 1.31 × 1022kg
Convert volume in km3 to m3: 6,970,174,651 × 1,000,000,000 = 6.970174651 × 1018m3
1.31 × 1022kg / 6.970174651 × 1018m3 = 1,879 kg/m3
- How does this new density calculation compare to the previous calculation (2051 kg/m3) when Pluto’s diameter was thought to be 2,302 km?
Take a look at some of the lessons, videos, activities and interactives related to Pluto. They’re a great way to engage students in STEM and learning more about their solar system!
- Video: What is a Dwarf Planet? (K-12)
Dwarf planets are a lot like regular planets. What’s the big difference? Find out in 60 seconds.
- Activity: Solar System Bead Activity (4-8)
The solar system is big, and Pluto is way out there! Students calculate scale distances to create a model of objects in our solar system.
Next Generation Science Standards: MS-ESS1-3
Common Core Math: 4.MD.A.2, 5.NBT.B.7
- Activity: How Far? How Faint? (9-12)
Calculate how much light Pluto receives from the sun, compared to Earth.
Common Core Math: HSF.IF.C.7.E
- Resource: Pluto Facts and Figures
Get lots of facts and figures about this dwarf planet in the Kuiper belt!
- Interactive: Eyes on Pluto
Ride along with New Horizons in this simulation of its closest approach to Pluto!
- Participate: Pluto Time
Though Pluto is a distant world with very different characteristics from Earth, for just a moment near dawn and dusk each day, you can experience “Pluto Time.” This is when the amount of light reaching Earth matches that of noon on Pluto. Find out exactly when Pluto Time happens in your area and share your photos online!
- News and Images: NASA New Horizons Website
Get the latest news and images from NASA's New Horizons mission.
TAGS: Pluto, New Horizons, Math, Teachable Moment