Archive for the ‘NASA News’ Category

Happy Anniversary, GRACE!

March 17th, 2016 by Adam Voiland and Holli Riebeek

Fourteen years ago, a rocket launched a pair of satellites known as the Gravity Recovery and Climate Experiment (GRACE) from the Plesetsk Cosmodrome in Russia. Though just 487 kilograms (1,074 pounds) each, the satellites have produced out-sized scientific advances. As we noted in 2012, few hydrologists believed the satellites would be able to detect—no less measure—changes in groundwater when they launched. As the map below shows, scientists working with GRACE data have shown otherwise.


This map shows how water supplies have changed between 2003 and 2012. GRACE measures subtle shifts in gravity from month to month. Variations in land topography or ocean tides change the distribution of Earth’s mass; the addition or subtraction of water also changes the gravity field. During that period, groundwater supplies decreased in California’s Central Valley and in the Southern High Plains (Texas and Oklahoma)—places that rely on ground water to irrigate crops. Eastern Texas, Alabama, and the Mid-Atlantic states also saw a decrease in ground water supplies because of long-term drought. The flood-prone Upper Missouri basin, on the other hand, stored more water over the decade.

GRACE has observed a number of significant changes in the water cycle. For instance, the mission revealed losses in ice mass on Greenland (where the loss is dramatic), Alaska, and Antarctica. The gravity measurements revealed how much the melting glaciers are contributing to sea level rise by recording both ice lost from land and the mass gained in the ocean. The image below shows changes in the Antarctic ice sheet between 2003 and 2010 as measured by GRACE.


GRACE measured changes in the Antarctic ice sheet from December 2003 through 2010. Red areas lost mass, while blue regions gained mass. (NASA map adapted from Luthke et al., 2012.)

As seen in the set of maps below, GRACE-based measurements can also be combined with ground-based measurements to map water at the surface, in the root zone, and as groundwater.


These maps compare conditions during the week of August 20, 2012, to the long-term average from 1948 to the present. For example, dark red regions represent dry conditions that should occur only 2 percent of the time (once every 50 years).

Thank you, GRACE! Here’s to many more years of observations. You can learn more about the mission here. Launch and clean room photos available here.

Remember to Vote

March 1st, 2016 by Mike Carlowicz

Here in the U.S., it’s election season. Don’t forget to vote.

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(Image by NASA Earth Observatory)

Though blizzards and cold snaps may have made you forget the news from last week, 2015 was the warmest year in NASA’s global temperature record, which dates back to 1880. During a January 2016 press conference (see the slides here), Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, explained that 2015 was 0.87 degrees C (1.57°F) above the 1951-80 average in the GISS surface temperature analysis (GISTEMP), one of four widely-cited global temperature analyses.

The statistical record is notable, but keep in mind that this year is just part of a much longer story about the climate. If you want to learn more about climate science as a whole rather than just the latest headlines, here are a few resources that you may find informative. The list is not comprehensive (and we are open to more suggestions), but it is a useful starting point for understanding climate science.

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(Image by Eric Roston and Blacki Migliozzi for Bloomberg Business)

The plot above comes from an interactive graphic called “What’s Really Warming the World?” Put together by Eric Roston and Blacki Migliozzi of Bloomberg News (with assistance from NASA climatologists Gavin Schmidt and Kate Marvel), the chart does an excellent job of breaking down the various factors (greenhouse gases, aerosols, solar activity, orbital variations, etc.) that affect climate. It parses out visually how much each factor contributes. The bottom line: greenhouse gases are absolutely central to explaining global temperature trends since 1880. The screenshot above hints at what the interactive looks like, but I highly recommend heading over to Bloomberg to see the full graphic.

Another invaluable graphic for understanding climate change is the “radiative forcing bar chart” below. (You can read an interesting post by Schmidt that explains how these charts have evolved over the decades). At first glance, the chart from the fifth assessment report by the United Nations’ Intergovernmental Panel on Climate Change may seem technical and difficult to understand. It is. But it is well worth looking up the technical terms.


(Image by the IPCC for the WG1AR5 Summary for Policy Makers)

In short, you are looking at a balance sheet of the major types of emissions that have either a warming or cooling effect on climate. Bars that extend to the left of the 0 signify a cooling effect; bars that extend to the right signify warming. The longer the bar, the more warming or cooling a given type of emissions contributes. What becomes immediately obvious is that carbon dioxide (CO2) and methane (CH4) have the biggest warming influence by far. The other well-mixed greenhouse gases — halocarbons, nitrous oxide (N20), chlorofluorocarbons (CFCs), and hydrochlorofluorocarbons (HCFCs) play a much smaller role.

The situation gets messy when you look at the role that short-lived gases and aerosols play. Some gases like carbon monoxide (CO) and the non-methane volatile organic compounds (NMVOC) — such as benzene, ethanol, formaldehyde — contribute to warming, but not much. Others like NOx actually slightly cool the climate overall if you consider how these gases interact with other substances in the atmosphere. Things get even messier if you look at aerosols. Mineral dust, sulfate, nitrate, and organic carbon have a cooling effect. On the other hand, black carbon causes warming. Albedo changes due to land use and changes in solar irradiance are minor in comparison to the other factors.

That’s a lot of variables, but one reason I like this chart is the error bars and the “level of confidence” column. The error bars give you a sense of how much uncertainty there is when it comes to the effects of various emissions. Look at the aerosol section, for instance, and you will see that the error bars are quite large and there is still some uncertainty about how aerosols affect clouds. The level of confidence column offers further clues to what scientists understand well and which areas they are less confident about. VH stands for very high confidence; H stands for high confidence; M stands for medium confidence; and L stands for low confidence.

What is striking is that even when you account for the error bars, there is little doubt that carbon dioxide and methane are warming the climate.


(Image by the NASA Global Climate Change website)

A third graphic, produced by NASA but based on data described here, is particularly compelling. Based on atmospheric information preserved in air bubbles in ancient ice cores, the plot offers a view of carbon dioxide levels in Earth’s atmosphere for the past 400,000 years. As this graph makes obvious, it has been a long time since carbon dioxide levels have been anywhere near where they are now.

For a much more recent view of carbon dioxide levels, the animation above is useful. Produced by NASA’s Scientific Visualization Studio, the video shows a time-series of the distribution and concentration of carbon dioxide in the mid-troposphere, as observed by the Atmospheric Infrared Sounder (AIRS) on the Aqua spacecraft. For comparison, the fluctuations in AIRS data is overlain by a graph of the seasonal variation and interannual increase of carbon dioxide observed at the Mauna Loa observatory in Hawaii. You can clearly see seasonal variations in carbon dioxide levels, but notice also that the mid-tropospheric carbon dioxide shows a steady increase in atmospheric carbon dioxide concentrations over time. That increase is because of human activity.

Image by Harvard University Press.

(Image by Harvard University Press)

My last recommendation will take longer for you to get through, but it is an invaluable resource. Physicist Spencer Weart offers a detailed but understandable account of the history of climate science research in his book The Discovery of Global Warming. You can read an extended version of book online on the American Institute of Physics’ website. If you make it all the way through, you will know far more than most people about the climate.


Photo by William Hrybyk for NASA’s Goddard Space Flight Center.

Earth Observatory has a pretty small staff — seven people — for a daily publication. There are a lot of other folks inside and outside of NASA who help us find and tell stories, but one man stands out from the rest. We might not be able to bring you a new Image of the Day, every day, if it were not for the unsung, unofficial eighth member of our team: Jeff Schmaltz. Our colleagues at NASA Goddard Space Flight Center (GSFC) have just published a Q&A with Jeff, and we thought you should know more about him.


“Curious Jeff” Schmaltz is on his third career.

What do you do and what is most interesting about your role here at Goddard? How do you help support Goddard’s mission?

Our group provides real-time Earth imagery from NASA Earth-observing satellites. The data is transmitted from the satellites to the ground stations, then to NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and then to the near-real-time data processing system. The data is basically numbers that we convert to images which we place on NASA websites such as

Our images come from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument flying on the Aqua and Terra satellites. Each satellite covers the entire Earth every day, so we receive two complete images of the Earth daily. From the time the satellite acquires data to the time we put the image on our website is roughly three to four hours.


What is your education?

I have three master’s degrees, one each in wildlife management, computer science and remote sensing.

Please tell us about your three different careers.

Since I was a kid in Connecticut, I wanted to work in the outdoors with animals. I got a master’s in wildlife management and then worked as a wildlife biologist for the U.S. Forest Service in the Daniel Boone National Forrest in Somerset, Kentucky. We counted endangered woodpeckers and maintained the forest. I spent all day outside walking through the forest and then came in later to do the paperwork.

I returned to school to get a master’s in computer science. Although I intended to apply my new skills to natural resource management, I was seduced by computer graphics, which was in its infancy. My next job was with the Department of Energy’s Pacific Northwest Laboratory in Richland, Washington. I wrote software for scientists, which was then called scientific programming. We also used the computer to prospect for gold, but we never found any.

I went back to school again, this time, for a master’s in remote sensing. Then I came to work for Goddard.

Is there a connection between your different careers?

My careers are connected through the common theme of computers. I’m excited that some of the imagery I’m currently creating is being used by the wildlife management and forestry community where I initially started.

What inspires you?

For many years, I have had a quote on my wall from Alfred Lord Tennyson’s poem “Ulysses”:

Yet all experience is an arch wherethro’

Gleams that untravell’d world whose margin fades

For ever and forever when I move.

I always want to move forward, to see what is beyond the horizon, to try something new. It’s the way I was born. I’m curious.

What are you searching for at Goddard?

I want to make a practical difference in people’s lives.

How do you make a practical difference?

The thing that is so exciting about my work is that the satellites were originally designed for scientific research, to collect data, but people at Goddard and around the world have found so many other practical uses. In 2000, the western U.S. had a very bad fire season. At that time, the data from our Earth-observing satellites showing the location of the forest fires took weeks to months to be publicly available. At the request of the Forest Service, a team from Goddard and the University of Maryland figured out how to make this data available the same day.

Many other uses have been found for this information including tracking drought and agricultural production, volcanic ash and dust storms.

What is the role of teamwork?

Everything that I do involves teamwork. Thousands of people, in hundreds of disciplines, living all over the world are involved.

What life lesson would you pass along?

You can take anyone’s life story and make a good, entertaining hour-and-a-half movie out of it. Everyone is more interesting than they think.

What would you say to somebody just starting at Goddard?

You never want to be the smartest person in a place because you want to learn from other people. At Goddard, you are surrounded by geniuses. Take advantage of that.

What is first on your bucket list?

I’ve always wanted to go to New Zealand to see the spectacular landscape and wildlife.

This article, compiled by Elizabeth M. Jarrell of NASA Goddard Space Flight Center, was originally published here.

Satellites as Superheroes

November 2nd, 2015 by Adam Voiland


Usually, comic book heroes wear tight pants and have superhuman strength. In the new educational manga Raindrop Tales from NASA, one of the heroes (Mizu-chan) evaporates water with her hair. The other (GPM) rides on a 3,900-kilogram satellite that observes rain and snow.

Look carefully at the art in the screenshots above, and you will find some telling details. Mizu-chan wears a flowing blue dress that symbolizes the many forms of water (snow, ice, rain, hail, water vapor, fresh water, salt water, etc.) found on Earth. Notice how her hemline is surrounded by clouds. Depending on her mood, the clouds form different types of precipitation.

GPM—named after the Global Precipitation Measurement mission—has blond hair and wears a kimono with a rain pattern on one half and a snow pattern on the other. Though he rides atop the GPM Core Observatory, that does not mean he has free reign over the satellite. Read the full comic to find out how GPM deals with meddlesome managers on the ground and what happens when he meets a diverse cast of characters in space.

The new manga is the culmination of an anime challenge sponsored by GPM’s education and outreach team. They made a call to artists from around the world to develop anime-themed comic book characters that could be used to teach students about the mission. Yuki Kiriga of Tokyo developed the GPM character; Sabrynne Buchholz of Colorado developed Mizu-chan. See some of their winning artwork below.


After finishing the manga, you may want to learn more about water. If so, try this story about the water cycle. “Viewed from space, one of the most striking features of our home planet is the water, in both liquid and frozen forms, that covers approximately 75 percent of the Earth’s surface,” the story begins.


The vast majority (about 96.5 percent) of that water, of course, fills the oceans. As for the rest of it, approximately 1.7 percent of Earth’s water is stored in the polar icecaps, glaciers, and permanent snow; another 1.7 percent is stored in groundwater, lakes, rivers, streams, and soil.

Only .001 percent of the water on Earth exists as water vapor in the atmosphere. But that tiny fraction is what GPM sees the best. To get a sense of the data GPM is collecting on a routine basis, see this story about the devastating rains that struck South Carolina in October 2015.



Some Insight on the Color of the Ocean

September 28th, 2015 by Mike Carlowicz

For nearly 20 years, Jim Acker, a contract support scientist at the NASA Goddard Earth Science Data and Information Services Center (GES DISC), has helped oceanographers compile and study data collected by satellites. A chemical oceanographer by training, he has been involved in the study of ocean color as viewed from space. He recently wrote a book for NASA about the history of the subject. He is also scheduled to deliver the NASA Goddard Science Colloquium on September 30 at 3:30 p.m. His talk is entitled: “Rise of the Machines: Computational Power and the History of NASA’s Ocean Color Missions.” He gave us a preview of the book and the talk this week.

NASA Earth Observatory: Most of us think of the ocean as blue; in some places, it looks green. So what do scientists mean when they refer to “ocean color?”


Jim Acker: Well, it’s blue and green and brown, and occasionally a few other related hues. Ocean color refers to the science of using satellite sensors to measure the light emanating from the ocean and determining what is in the water based on those light measurements. The main things that change the color of the ocean are phytoplankton—the floating plants at the base of the ocean food chain—dissolved colored substances, and different kinds of sediments.

EO: What are some of the things we have learned by looking at the ocean from satellites?

Acker: One of the main things done with global observations has been estimating how much carbon is produced by the growth of phytoplankton. Ocean color observations have shown how much this can vary, particularly with events like El Niño or La Niña in the Pacific Ocean.

The satellite view also can show how much variation there is over relatively short distances. A ship could be sitting in nice clear water, and just a few tens of kilometers away there could be a strong phytoplankton bloom that they would never know about without observations from space.


The observations also have helped understand phytoplankton patterns in hard-to-reach places like the polar seas and the Red Sea or Arabian Sea. The interaction of the land and ocean, with weather patterns and river inflows, has also been better observed.

EO: Have there been any big surprises?

Acker: Definitely. One of the biggest surprises from the Coastal Zone Color Scanner, the first NASA ocean color mission, was truly how much the ocean varied over small distances. Where oceanographers used to draw simple lines, they realized there were swirls and spirals and curlicues and loops and jets and rings. It was much more complicated.

Another surprise when SeaWiFS and MODIS started making global observations was how cloudy it is over the oceans.  It takes really impressive data processing to get accurate values because of that.


And because the satellites make continuous observations, they have observed many different features that weren’t where we expected them to be or they happened more often than we thought.

EO: What provoked you to write a book?

Acker: NASA wanted to have some histories of NASA science, and I wanted to tell the history of ocean color because it’s been so successful. It’s like a well-trained, elite athlete:  they make what they do look easy, though a lot of hard effort and training makes that possible.


Ocean color measurements are very difficult to make, but because the missions have been so successful, the public and even most scientists have just seen the beautiful results and have not realized the dedicated, behind-the-scenes work that made them possible. It isn’t just about seeing images from space on a computer monitor. To be sure the data is accurate, there have been some true high-seas adventures. I was able to get a lot of real-life experiences from the scientists and engineers into the book.

EO: What is your favorite book about science?  And your favorite writer?

Acker: My favorite book that was sort of about science was The Map that Changed the World by Simon Winchester; I also enjoyed his book about the eruption of Krakatoa. My favorite writers are Pat Conroy and J.R.R. Tolkien. The late Stephen Jay Gould wrote a lot of things about science I liked.  And I have to mention that I just read Andy Weir’s The Martian and was quite impressed. I’m looking forward to seeing the movie.



This is a cross-post from Laura Rocchio and our colleagues at NASA’s Landsat Science Team.

The European Space Agency’s Sentinel-2A successfully launched into orbit on June 22, 2015, from Europe’s Spaceport in Kourou, French Guiana, aboard a Vega rocket (10:52 p.m. local time; 01:52 GMT).

The Sentinel-2A satellite has spectral bands similar to Landsat 8’s (excluding the thermal bands of Landsat 8’s Thermal Infrared Sensor). The placement of the Sentinel-2A bands, as compared to Landsat 8 and Landsat 7 bands, can be seen in the graphic below.


The main visible and near-infrared Sentinel-2A bands have a spatial resolution of 10 meters, while its “red-edge” (red and near-infrared bands)—specifically designed to monitor vegetation—along with its two shortwave infrared bands have a 20-meter spatial resolution, and its coastal/aerosol, water vapor, and cirrus bands have a 60-meter spatial resolution.

During the development of Landsat 8 and Sentinel-2A, calibration scientists from both projects worked together to cross-calibrate the sensors. Many scientists and researchers are looking forward to collectively using data from Landsat 8 and Sentinel-2A.

Sentinel-2A alone provides 10-day repeat coverage of Earth’s land areas. In combination with the 8-day coverage from Landsat 7 and 8 combined, users can look forward to better-than-weekly coverage at moderate resolution. Repeat coverage capabilities will further increase with the planned launch of a second Sentinel-2 satellite (Sentinel-2B) in 2016.

According to ESA, “As well as monitoring plant growth, Sentinel-2 will be used to map changes in land cover and to monitor the world’s forests. It will also provide information on pollution in lakes and coastal waters. Images of floods, volcanic eruptions and landslides will contribute to disaster mapping and helping humanitarian relief efforts.”

After the successful Sentinel-2A launch, Dr. Garik Gutman, the NASA Land Use / Land Cover Change program manager, said, “We are looking forward to new exciting data to complement Landsat observations and to collaborative research—especially because ESA followed USGS in its open data policy.” This sentiment is echoed by many in the Landsat community.

Read more about Sentinel 2A by clicking here

The following is a statement from NASA Administrator Charles Bolden on the House of Representatives’ NASA authorization bill:

“The NASA authorization bill making its way through the House of Representatives guts our Earth science program and threatens to set back generations worth of progress in better understanding our changing climate, and our ability to prepare for and respond to earthquakes, droughts, and storm events.

NASA leads the world in the exploration of and study of planets, and none is more important than the one on which we live.

In addition, the bill underfunds the critical space technologies that the nation will need to lead in space, including on our journey to Mars.”

Tournament Earth 2015 Champion

April 10th, 2015 by Adam Voiland


Tournament Earth 2015 has come to a dramatic end. Despite some tough match ups, the colorful faults of Xinjiang fought off a bolt of lightning (as seen from the International Space Station), taking the #2 seed from the art division all the way to the championship.

This year’s victory was a first for an image from a Landsat satellite. In 2014, the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra captured the winning shot. In 2013, it was the Advanced Land Imager (ALI) on the Earth Observing-1 (EO-1) satellite. This was also the first year that an image not associated with the Canary Islands won the tournament.

As noted in our original Image of the Day, Piqiang Fault is a northwest trending strike-slip fault that runs roughly perpendicular to a series of thrust faults. The thrust faults are marked by the colorful southeast-to-northeast running ridges. The ridges are offset by about 3 kilometers (2 miles) due to the strike-slip fault. For another perspective on the faults, see how they look in the near infrared and shortwave infrared (below).  In the near infrared, variations in mineral content, vegetation, and water cause the patterns of light and dark. Below that, comparing the differences between 3 shortwave infrared bands highlights the mineral geology surrounding the fault.



Though obvious from above, the Piqiang Fault can be a challenge to see from the ground. “You can’t actually see the fault unless you hike into the mountains,” explained Sebastian Turner, a geologist who has conducted studies in the area. If you would like to learn more about the geology of this area, I would recommend looking through Turner’s study or this one by Mark Allen.

Thank you for voting!

A Century Studying Flight

March 3rd, 2015 by Mike Carlowicz

“Today marks a special anniversary for the NASA family,” Administrator Charles Bolden wrote in a letter to NASA employees.

On March 3, 1915, the U.S. Congress created the National Advisory Committee for Aeronautics (NACA), the organization from which NASA was later created in 1958. Bolden notes that NACA was initially formed because political leaders at the time were concerned that the United States was losing its edge in aviation technology to Europe, where World War 1 was raging.


One of NACA’s missions was to “supervise and direct the scientific study of the problems of flight with a view to their practical solution.” Research by NACA funded engineers led to fundamental advances in aeronautics that enabled victory in World War II, spawned a world-leading civil aviation manufacturing industry, propelled supersonic flight, supported national security, and laid the foundation for modern air travel and the Space Age. Many names we know from the early days of space exploration got their start at the NACA – including Robert Gilruth, Hugh Dryden, Chris Kraft, Gene Kranz and Neil Armstrong, among many others. A number of the laboratories and wind tunnels built in the NACA era are still at work today.

You can learn more about NACA by visiting this page on the main NASA web site. And you can watch pieces of the centennial symposium here.