In the News
A pair of Earth orbiters designed to keep track of the planet's water resources and evolving water cycle is scheduled to launch this month – no earlier than May 22, 2018. The Gravity Recovery and Climate Experiment Follow-On mission, or GRACE-FO, will pick up where its predecessor, GRACE, left off when it completed its 15-year mission in 2017. By measuring changes in Earth’s gravity, the mission will track water movement around the globe, identifying risks such as droughts and floods and revealing how land ice and sea level are evolving. The GRACE-FO mission is a great way to get students asking, and answering, questions about how we know what we know about some of the major components of Earth’s water cycle: ice sheets, glaciers, sea level, and ground-water resources.
How It Works
Earth Science Lessons
Explore a collection of standards-aligned lessons for grades K-12 all about our home planet.
The GRACE-FO mission, a partnership between NASA and the German Research Centre for Geosciences (GFZ), will measure small variations in Earth’s mass to track how and where water is moving across the planet. This is no easy task, as water can be solid, liquid or gas; it can be in plain sight (as in a lake or glacier); it can be in the atmosphere or hidden underground; and it’s always on the move. But one thing all this water has in common, regardless of what state of matter it is in or where it is located, is mass.
Everything that has mass exerts a gravitational force. It is this gravitational force that GRACE-FO measures to track the whereabouts of water on Earth. Most of Earth's gravitational force, more than 99 percent, does not change from one month to the next because it is exerted by Earth’s solid surface and interior. GRACE-FO is sensitive enough to measure the tiny amount that does change – mostly as a result of the movement of water within the Earth system.
GRACE-FO works by flying two spacecraft in tandem around Earth – one spacecraft trailing the other at a distance of about 137 miles (220 kilometers). By pointing their microwave ranging instruments at each other, the satellites can measure tiny changes in the distance between them – within one micron (the diameter of a blood cell) – caused by changes in Earth’s gravitational field. Scientists can then use those measurements to create a map of Earth’s global gravitational field and calculate local mass variations.
As the forward spacecraft travels over a region that has more or less mass than the surrounding areas, such as a mountain or low valley, the gravitational attraction of that mass will cause the spacecraft to speed up or slow down, slightly increasing or decreasing the relative distance between it and its trailing companion. As a result of this effect, GRACE-FO will be able to track water as it moves into or out of a region, changing the region’s mass and, therefore, its gravity. In fact, the previous GRACE spacecraft measured a weakening gravity field over several years in Central California, enabling an estimate of aquifer depletion, and in Greenland, providing accurate measurements of ice melt over more than 15 years.
Find out more about how the mission works in the video below, from JPL's "Crazy Engineering" video series:
Why It’s Important
Tracking changes in our water resources and the water cycle is important for everyone. The water cycle is one of the fundamental processes on Earth that sustains life and shapes our planet, moving water between Earth's oceans, atmosphere and land. Over thousands of years, we have developed our civilizations around that cycle, placing cities and agriculture near rivers and the sea, building reservoirs and canals to bring water to where it is needed, and drilling wells to pump water from the ground. We depend on this cycle for the water resources that we need, and as those resources change, communities and livelihoods are affected. For example, too much water in an area causes dangerous floods that can destroy property, crops and infrastructure. Too little water causes shortages, which require us to reduce how much water we use. GRACE-FO will provide monthly data that will help us study those precious water resources.
Changes to Earth’s water over multiple years are an important indicator of how Earth is responding in a changing climate. Monitoring changes in ice sheets and glaciers, surface and underground water storage, the amount of water in large lakes and rivers, as well as changes in sea level and ocean currents, provides a global view of how Earth’s water cycle and energy balance are evolving. As our climate changes and our local water resources shift, we need accurate observations and continuous measurements like those from GRACE and GRACE Follow-On to be able to respond and plan.
As a result of the GRACE mission, we have a much more accurate picture of how our global water resources are evolving in both the short and long term. GRACE-FO will continue the legacy of GRACE, yielding up-to-date water and surface mass information and allowing us to identify trends over the coming years.
Teach ItHave students interpret GRACE data for themselves:
Tracking Water With NASA Satellite Data
Using real data from NASA’s GRACE satellites, students will track water mass changes in the U.S.
Time 1-2 hrs
Get students learning about global water resources:
Explore a collection of standards-aligned lessons all about water and the water cycle.
Teach students to read, interpret and compare “heat map” representations of Earth science data:
How to Read a Heat Map
Students learn to read, interpret and compare “heat map” representations of Earth science data.
Time 30 mins - 1 hr
Explore MoreNASA's Space Place:
In the Education Office at NASA’s Jet Propulsion Laboratory, we’re always working to bring exciting scientific content to K-12 classrooms. Educators can access many of these free resources, classroom materials and activities online, and we’re adding more all the time. The inspiration for these products often comes from the work being done at JPL and NASA, but sometimes it’s the teachers we work with whose creative ideas inspire the lessons we share with our community of STEM educators. Our new column, Teacher Feature, is an effort to capture those creative ideas and highlight the teachers behind them.
Featured Lesson: How to Read a Heat Map
Students learn to read, interpret and compare “heat maps” representing Earth science data.
LoriAnn Pawlik recently shared her NASA-inspired lesson during a professional development workshop hosted by the agency.
LoriAnn teaches STEM to grades K-5 at Penn Elementary School in Prince William County, Virginia, which focuses on students learning English, as well as those with learning disorders and autism. When she recently came across a lesson on the NASA/JPL Edu website, she saw an opportunity to bring real-world NASA data to her students.
How do you use NASA in the classroom?
Using the lesson “How to Read a Heat Map” as a jumping-off point, LoriAnn had her students first dive into the practice of reading and interpreting graphs. From here, she extended the lesson with an exploration of NASA satellites and the data they collect, focusing on the Gravity Recovery And Climate Experiment, or GRACE mission, to tie in with a community science night on water science.
GRACE was launched in 2002 to track changes in the distribution of liquid water, ice and land masses on Earth by measuring changes in the planet’s gravity field every 30 days. Circling Earth 16 times each day, GRACE spent more than 15 years collecting data – all of which is available online – before its science mission ended last October. The mission provided students the perfect context to study climate and water through authentic NASA data.
How did students react to the lesson?
LoriAnn set the stage for her students by explaining to them that they would be providing their data to NASA scientists.
“I told them that I was working on a project for a scientist from NASA-JPL and that we needed their help,” she said via email. “By the time I gave them the background and showed a brief GRACE video, they were all in – excited, eager enthusiastic! It helped that each table, or ‘engineering group,’ was responsible for a different U.S. state.”
As a result, students were able to plot the changes in gravitational fields for multiple locations over several years.
What are other ways you use NASA lessons or resources?
By extending the lesson, LoriAnn gave her students a sense of authentic ownership of the data and practice in real scientific analysis. But it wasn’t her first time uniting NASA science with her school curriculum:
“I'd been working with our second-graders on field studies of habitats,” LoriAnn explained. “We observed, journaled and tracked the migration of monarch butterflies, discussed what happened to habitats of living things since Hurricane Harvey and Hurricane Irma were just going through, and then I used the [NASA Mars Exploration website] to have students extend the findings to space habitats.”
Have a great idea for implementing NASA research in your class or looking to bring NASA science into your classroom? The Educator Professional Development Collaborative, or EPDC, can help. The EPDC at JPL serves educators in the greater Los Angeles area. Contact JPL education specialist Brandon Rodriguez at firstname.lastname@example.org. Note: Due to the popularity of EPDC programs, JPL may not be able to fulfill all requests.
Outside the Southern California area? The EPDC operates in all 50 states. Find an EPDC specialist near you.
The EPDC is managed by Texas State University as part of the NASA Office of Education. A free service for K-12 educators nationwide, the EPDC connects educators with the classroom tools and resources they need to foster students’ passion for careers in STEM and produce the next generation of scientists and engineers.
In the News
Earth Day, the day set aside each year to celebrate our planet and bring attention to the natural world, is on April 22, 2017. More than one billion people are expected to participate in Earth Day events around the globe that will draw attention to what we know about Earth, how it is changing and how we can be kind to our home planet.
One of the ways that NASA participates – not just on Earth Day, but also year-round – is by collecting and analyzing science data from sensors on Earth and satellites. These data allow us to monitor the health of our planet and better understand how and why it is changing.
This year, to highlight the importance of these data, NASA is inviting people to “adopt” a portion of Earth’s surface and obtain a snapshot of some of the satellite data available for their adopted location. Even though you’ll have no legal or ownership rights to this region, it will be fun to learn about the various types of data available for different locations on Earth. Find out how you can participate.
How It Works
NASA’s fleet of Earth-observing satellites and airborne sensors provides us with data about such vital information as carbon dioxide, carbon monoxide, global land and sea temperature, ice, sea surface salinity, and chlorophyll – just to name a few. The satellites and sensors collect these data over time and from as many perspectives as possible, allowing us to discern trends in the data.
A snapshot of data is just one piece of a much larger puzzle because it only gives us an indication of what was happening at the exact moment that data was captured. Even data collected over a year has its limitations because local conditions may ebb and flow over longer time periods. Collecting data about multiple elements of the Earth system over decades or centuries enables us to develop correlation and causation models, powerful indicators of why trends are developing as they are. And using multiple platforms (satellite, aerial, Earth-based) to measure data enables us to validate our data sets.
Why It’s Important
Humans are dependent on a healthy and functioning Earth to survive, which means we need to keep a close eye on all Earth systems and our impacts on those systems. This process of collecting data over time from multiple perspectives, discerning trends and validating the data is crucial to understanding our planet and helping policymakers formulate actions we can take to preserve Earth for future generations.
First, introduce students to the kinds of data scientists use to study Earth. Participate in NASA’s Adopt the Planet campaign to receive a snapshot of Earth science data for one patch of Earth. Then encourage students to dig deeper with these standards-aligned lessons:
- *NEW* Lesson: Earth Science Data Visualizations – How to Read a Heat Map – Students learn to read, interpret and compare “heat map” representations of Earth science data.
- Lesson: Graphing Sea Level Trends – In this activity, students will use sea-level rise data to create models and compare short-term trends to long-term trends. They will then determine whether sea-level rise is occurring based on the data.
- Lesson: Graphing Global Temperature Trends – Students use global temperature data to create models and compare short-term trends to long-term trends.
- 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.
- Earth Science Lessons
- NASA Eyes on the Earth
- NASA’s Earth Observatory
- NASA’s Worldview
- Earth Vital Signs
- Earth Minute Videos
NASA hosted a telecon today on the role carbon emissions are playing in climate change and the steps the agency is taking to answer some of the most pressing questions about our planet's future.
Currently, Earth's land cover and oceans are shouldering much of the impacts of human emissions -- about half in fact. But it's unclear if and how long that will continue. Any changes in that support system could mean even bigger changes in Earth's climate. NASA is using a number of strategies and technologies to study the problem, including ground- and space-based instruments, supercomputer simulations and field studies, but climate scientists say there's still more work to do to truly understand how carbon moves among the land, oceans and atmosphere.
Learn more about carbon, climate and NASA's ongoing research with these resources:
News and Blogs
- Feature: "A Breathing Planet, Off Balance"
- Feature: "Seven Case Studies in Carbon and Climate"
- Earth Right Now Blog
Lessons and Activities
Multimedia and Interactives
Facts and Figures
Join the Conversation
- Reddit AMA: "We're NASA scientists studying the role of carbon in our planet's climate. Ask us anything!"
- Follow @EarthVitalSigns on Twitter
- Follow NASA Climate Change on Facebook
In the News
“Sea level rise” – we hear that phrase, but what does it mean, really? How does it affect us? Do I have to be concerned about it in my lifetime? These are all great questions!
Sea level rise is the increasing of the average global sea level. It doesn’t mean that seas are higher by the same amount everywhere. In fact, in some areas, such as the west coast of the US, sea level has actually dropped slightly … for now. But before we get into that, let’s understand the main contributors to sea level rise:
- Melting mountain glaciers - Glaciers are bodies of ice on land that are constantly moving, carving paths through mountains and rock. As glaciers melt, the runoff flows into the oceans, raising their levels.
- Melting polar ice caps - Think of our north and south polar regions. At both locations, we have ice on land (“land ice”) and ice floating in the ocean (“sea ice”). Melting sea ice, much like ice cubes melting in a drink, does not affect the level of the oceans. Melting land ice, however, contributes to about one third of sea level rise.
- Thermal expansion of water - Consider that our oceans absorb over 90 percent of the heat trapped by greenhouse gasses in Earth’s atmosphere. When water heats up, its molecules become more energetic, causing the water to expand and take up more room, so that accounts for about a third of sea level rise.
Let’s take a closer look at global sea levels. Sea level is not constant everywhere. This is because it can be affected by ocean currents and natural cycles, such as the Pacific Decadal Oscillation, or PDO, a 20- to 30-year cyclical fluctuation in the Pacific Ocean’s surface temperature. Because of the PDO, right now the Eastern Pacific has higher sea levels than usual, while the Western Pacific has lower sea levels than usual. However, the global average of 3 millimeters of sea level rise per year is increasing and the rate that it’s increasing is speeding up. That means that sea level is rising, and it’s rising faster and faster. Take a look at this video for some great visuals and further explanation of how phenomena such as the Gulf Stream affect local sea level heights.
Why It's Important
You may be asking yourself, how do we know sea levels are rising? Well, a couple of ways. First, for the past 23 years we have been using data from several NASA satellites to constantly measure sea surface height around the globe. Data from these ocean altimeters is integrated to refine and calibrate measurements. Additionally, we have tide gauges on Earth to ground-truth (locally validate) our satellite measurements. As for historical data, we use sediment cores -- drillings into Earth that yield the oldest layers on the bottom and the youngest layers on top -- to examine where oceans once reached thousands of years ago.
Locally, folks are making observations – and already seeing the impacts of sea level rise on their communities. Places such as Miami are now experiencing regular flooding in downtown city streets at high tide. The South Pacific island nation of Kiribati saw a 2.6 millimeter rise in sea level between 1992 and 2010. That may not seem like much, but when you consider that the land only sits about 2 meters above sea level, that’s a big deal; some villages have already had to relocate to escape the rising tides. Residents of China's Yellow River delta are swamped by sea level rise of more than 25 centimeters (9 inches) a year. Even NASA is concerned about some of its facilities that are located in low-lying areas.
Besides wiping out dry land, encroaching salt water can pollute our fresh water supplies and damage fresh-water dependent ecosystems. It’s not just fresh water rivers and lakes that are at risk – our aquifers, or natural underground water storage, are at risk of filling with salt water as the ocean encroaches on the land above them.
Clearly, sea level rise is something that is already affecting people and will continue to do so. All three contributors to sea level rise can be attributed to the warming of the Earth system. Warming temperatures cause mountain glaciers and polar ice caps to melt, thereby increasing the volume of water in the oceans. At the same time, our oceans are getting warmer and expanding in volume as a result of this heat (thermal expansion). Since 1880, global sea level has risen 20 centimeters (8 inches); by 2100, it is projected to rise another 30 to 122 centimeters (1 to 4 feet). Watch this video for some illustrations of these facts:
Also check out the Climate Time Machine for Sea Level to see what impact a 1 meter to 6 meter rise in sea level will have on the coastal US and other areas of the world.
If we can control our contributions to the rise in greenhouse gases in Earth’s atmosphere, we can perhaps level out the warming of the Earth system and eventually stabilize our sea levels. In the meantime, we need to be prepared for the impact encroaching seas will have on our coastal communities and water supplies.
To engage your students in analyzing real climate data and drawing their own conclusions, have them try these Next Generation Science Standards and Common Core Mathematics aligned problems.
Have students use these two satellite data graphs to answer the questions below. (To obtain exact data points, place your mouse on the section of the graph you would like to examine.)
- What is the source of the data for each graph?
- Which years are covered by each graph?
- Is one graph a better representation of global sea levels than the other? Why or why not?
- By approximately how many millimeters did sea level rise between:
A) 1910 and 1930?
55 mm – 45 mm = 10 mm (approx.)B) 1930 and 1950?
120 mm – 55 mm = 65 mm (approx.)
- What is the approximate average rate of increase of sea level rise between 1870 and 2000?
Note: students of various math abilities may approach and solve this problem within their capabilities. The most sophisticated approach is to find the slope of the line of best fit. The correct answer is approximately 1.5 mm per year.
- By how many millimeters did sea level rise between the first measurement obtained in January 1993 and the first measurement obtained in January 2013?
(55.69)-(-16.56) = 72.25 mm
- What is the approximate rate of sea level rise between January 1993 and present?
Note: The answer for this problem is directly stated at the top of the graph, 3.21 mm per year. Students of various math abilities may approach and solve this problem within their capabilities. The most sophisticated approach is to find slope of the line of best fit.
- By how much did the average global temperature change, and did it increase or decrease between 1910 and 1930? How about between 1930 and 1950?
A) (-0.12)-(-0.46) = 0.34 (increase by 0.34 degrees C)
B) (-0.19)-(-0.12) = -0.07 (decrease by 0.07 degrees C)
- Compare your answers to question number 8 with your answers to question number 4. Can you offer an explanation for the correlation or lack thereof?
Encourage students to critically examine the graph, noting the temperature increase that occurred between 1930 and 1944, preceding the temperature decrease between 1944 and 1950. Students familiar with heat capacity should include this concept in their discussion.
- What is the approximate average global temperature rise per year from the first measurement taken in 1880 to present?
Note: students of various math abilities may approach and solve this problem within their capabilities. The most sophisticated approach is to find slope of the line of best fit. The most conservative answer is 0.007°C per year, the best-fit answer is closer to 0.01°C.
Have students examine this line graph for average global temperature and use it to answer the questions below.
Now, what can you do to be kind to Earth and do your part to control greenhouse gases in our atmosphere?
- First, watch this video to learn more about our changing climate:
- Next, check out this interactive feature to see what others around the globe are doing and add your ideas.
News and Resources
- Earth Right Now Blog
- Article: "Warming Seas and Melting Ice Sheets"
- Article: "The Fingerprints of Sea Level Rise"
- NASA’s Climate Change website
- NASA Earth Missions