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Earth Matters

May Puzzler

May 19th, 2020 by Adam Voiland

Every month on Earth Matters, we offer a puzzling satellite image. The May 2020 puzzler is above. Your challenge is to use the comments section to tell us what we are looking at, where it is, and why it is interesting.

How to answer. You can use a few words or several paragraphs. You might simply tell us the location, or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure feature. If you think something is interesting or noteworthy, tell us about it.

The prize. We cannot offer prize money or a trip to Mars, but we can promise you credit and glory. Well, maybe just credit. Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the first person to correctly identify the image at the bottom of this blog post. We also may recognize readers who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have shaped the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you would like to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the past few months, or if you work in geospatial imaging, please hold your answer for at least a day to give less experienced readers a chance.

Releasing Comments. Savvy readers have solved some puzzlers after a few minutes. To give more people a chance, we may wait 24 to 48 hours before posting comments. Good luck!

See “In a Desert Not So Far Away for the Answer” Image of the Day for the answer. Congratulations to Dan O’Brien for being the first reader to post the answer on the Earth Matters blog.

Smoke Over Lake Maracaibo

May 8th, 2020 by Adam Voiland

NOAA’s GOES-16 satellite captured a series of images showing a black smoky plume spreading on April 25, 2020. Animation credit: NOAA Environmental Visualization Laboratory

As noted in a recent Image of the Day (“A Fiery Month in Zulia”) satellites have detected lots of fire activity in western Venezuela in recent weeks. Just as we were finishing that story, a surprisingly large, dark smoke plume appeared in VIIRS and MODIS imagery. It bore little resemblance to the smaller, gray plumes that we had been watching. Forest and crops fires had caused the earlier plumes; the new black smoke was caused by a brush fire that had spread into a crude oil storage area, according to news reports.

The animation above shows the progression of the plume on the morning of April 25, 2020. The images were collected at 10 minute intervals by the Advanced Baseline Imager (ABI) on NOAA’s GOES-16 satellite. Sensors on other satellites caught glimpses of the short-lived plume as well, including the Multispectral Instrument (MSI) on the European Space Agency’s Sentinel-2 satellite and the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite.

With dozens of firefighters battling the blaze, it was extinguished by the next day. On April 26, 2020, there were no signs of smoke or active fires visible in MODIS and VIIRS images of that area.

Colorized scanning electron micrograph of a dying cell (blue) infected with SARS-COV-2 virus particles (red). Image Credit: NIAID.

“As you take this constant drumbeat of new information and research in, remember that this virus is new to science and people have only just started studying it. Doing high-quality, definitive science takes time, sometimes a long time. The appetite for answers is understandably intense, but we also have to try to balance that hunger with patience.”

– Benjamin Zaitchik, a Johns Hopkins University researcher working to understand whether environmental factors are affecting the spread of coronavirus.

Ever since a new and deadly strain of coronavirus (SARS-CoV-2) emerged in China and then spread around the world, the virus has upended life in many countries. Scientists at NASA and other institutions have hustled to track and make sense of our new reality with every tool and technique at their disposal, including satellite data.

As several comprehensive NASA-funded research projects get started, here is a quick roundup of some of the more interesting satellite-related findings about the science of coronavirus and its effects on the environment.

A Welcome Breath of Cleaner Air

Much of the news about the new coronavirus is grim, but observations of air quality offer a breath of fresh air. Several satellite sensors have detected drops in air pollutants — including nitrogen dioxide, carbon monoxide, and fine particles — following restrictions on travel and economic activity. Teams of scientists have spotted changes in China, Europe, the U.S. Northeast and Southeast, and India.

Look here for some tips on how to find and visualize changes in nitrogen dioxide, one of the gases that most clearly shows the effects of quarantines and economic shutdowns. Also, look here for nitrogen dioxide data for cities all around the world. But beware: As University of Georgia meteorologist Marshall Shepherd has pointed out, clouds and rain can create confusing changes in nitrogen dioxide that have nothing to do coronavirus restrictions.

A New Coronavirus Tracking Tool

Image Credit: NASA SEDAC

Given how much the virus has changed daily life, many of us find ourselves turning into armchair epidemiologists, trying to make sense of how the virus is spreading and what it means for our local area. If you are interested in taking a close look at new data as it comes in, this simple-to-use mapping tool from NASA’s Socioeconomic Data and Applications Center (SEDAC) might be of interest. It features demographic data, along with regularly updated information on reported global cases of the novel coronavirus (COVID-19). There is a short user guide here.

A Stream of New Seasonality Studies

One of the key unknowns about the new coronavirus is whether environmental conditions — such as temperature, humidity, and exposure to ultraviolet light — have any effect on how the virus spreads or on the severity of the symptoms. NASA-funded researchers are starting to investigate this in several ways, while others are using NASA data in their models and analyses.

Some controlled laboratory research has suggested that exposure to warm air may make it more difficult for the virus to survive and spread. That has led many researchers around the world to start analyzing epidemiological and meteorological data to see if certain environmental factors have a significant impact on the virus in the real world. At this point it is too early to say, declared the National Academy of Sciences in a report on April 7, 2020, but the research continues.

Learning to Live with Social Isolation

Billions of people are facing something that NASA astronauts have plenty of experience with—living in social isolation for long periods with just a few other people. Here are some tips from astronaut Anne McClain and psychologist Tom Williams.

Antarctic Iceberg Breaks and Makes a New Berg

May 4th, 2020 by Kathryn Hansen

Antarctic iceberg A-68A, which broke from the Larsen C Ice Shelf in 2017, has been floating solo in recent years. Not anymore. The colossal iceberg finally fractured in late April 2020, spawning a new companion named A-68C.

The break was not exactly surprising. A few weeks ago, we published this image (above) showing Iceberg A-68A on April 9, 2020. The iceberg on that day was still intact, but it had drifted north into dangerously warm waters. Christopher Readinger of the U.S. National Ice Center (USNIC) noted at the time: 

“I’m surprised at how well it’s sticking together. It’s been in warmer water for a few months now and it’s not exactly a very thick berg, so I expect it will break up sometime soon, but it’s showing no signs of that yet.”

Less than two weeks later, that’s exactly what happened. Satellite images on April 22 showed that a new iceberg had broken off from A-68A. The pair is now drifting at the edge of the Weddell Sea and South Atlantic Ocean, near the South Orkney Islands. The image below, acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NASA-NOAA Suomi-NPP satellite, shows the bergs on May 3, 2020. 

Iceberg A-68C measures about 11 nautical miles long and 7 nautical miles wide (20 by 13 kilometers). That’s small compared to its parent berg A-68A, which now measures 82 by 26 nautical miles (152 by 48 kilometers), but it is large enough to be named and tracked by the U.S. National Ice Center

Even after shedding the sizable piece of ice, A-68A is still the largest iceberg currently floating anywhere on Earth. It has calved only one other named berg, forming A-68B in July 2017 just after the initial calving event from the ice shelf. 

To see where the iceberg duo goes from here, you can follow them in satellite imagery available on Worldview.

April Puzzler

April 21st, 2020 by Kasha Patel


Every month on Earth Matters, we offer a puzzling satellite image. The April 2020 puzzler is above. Your challenge is to use the comments section to tell us what we are looking at, where it is, and why it is interesting.

How to answer. You can use a few words or several paragraphs. You might simply tell us the location, or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure feature. If you think something is interesting or noteworthy, tell us about it.

The prize. We cannot offer prize money or a trip to Mars, but we can promise you credit and glory. Well, maybe just credit. Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the first person to correctly identify the image at the bottom of this blog post. We also may recognize readers who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have shaped the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you would like to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the past few months, or if you work in geospatial imaging, please hold your answer for at least a day to give less experienced readers a chance.

Releasing Comments. Savvy readers have solved some puzzlers after a few minutes. To give more people a chance, we may wait 24 to 48 hours before posting comments. Good luck!

See our “Filling up Lake Carnegie” Image of the Day for the answer.

Assessing Locust Damage from the Ground

April 16th, 2020 by Kasha Patel


East Africa is experiencing one of its worst locust outbreaks in decades. The voracious insects are devouring thousands of hectares of farmland and forests, and threatening food security for millions across the region, which is already vulnerable to food shortages.

Locusts swarm a field in Elgeyo Marakwet County in Kenya. Photo credit: Gentrix Machenje

To help manage outbreaks, NASA scientists are developing tools to track locust breeding grounds and to assess crop damage. We previously reported on the satellite data used in these assessments, but researchers are also using ground-based observations from several local organizations and government offices. Such information is used to validate estimates of crop conditions made from satellite imagery and included in international crop forecasts.

“Our ground partners give monthly updates on crop conditions and major events like flooding and disease outbreaks,” said Catherine Nakalembe, a food security researcher with NASA SERVIR and NASA Harvest. “They help provide critical ground information when the remote sensing data are not sufficient.”

The following photos, taken by people in Uganda and Kenya, show some of the effects of the locust outbreak on farms.

Elgeyo Marakwet County, Kenya

Kenya is experiencing its worst locust outbreak in 70 years. The image at the top of this page and the one below shows locusts (yellow) swarming a field in March 2020.

Photo credit: Gentrix Machenje


The images were taken by Gentrix Machenje. Machenje is a county officer who works with NASA SERVIR and provides information for Kenya’s National Crop Monitor.


Karamoja, Uganda

The photos below were taken in early April 2020 in the Karamoja region of northeast Uganda. Officials believe the locusts hatched from eggs laid a few weeks ago.

Photo credit: Evans Noble Opiolo


The images were taken by Evans Noble Opiolo, an agricultural officer in the Nakapiripirit District who also contributes to a Disaster Risk Financing Project for Uganda’s Office of the Prime Minister. Such officers are reporting on locust locations and are often present when ground-control operations, such as pesticide spraying, are in progress.

Photo credit: Evans Noble Opiolo
Photo credit: Evans Noble Opiolo

To learn more about NASA’s response to the 2020 locust outbreaks, read our recent article.

Nimbus-4: A Satellite Pioneer For Ozone Research

April 9th, 2020 by Adam Voiland

When NASA launched the Nimbus-4 satellite 50 years ago, nobody knew the ozone layer over Antarctica was thinning. And nobody knew that chlorofluorocarbons (CFCs)—long-lived chemicals that had been used in refrigerators and aerosol sprays since the 1930s—were responsible.

But the mission included a sensor called the Backscatter Ultraviolet (BUV) experiment capable of measuring ozone nonetheless. “We simply wanted to measure the atmosphere. It was curiosity-driven research,” said Pawan Bhartia, an atmospheric scientist at NASA’s Goddard Space Flight Center in an interview about the discovery of the ozone hole.

Developed by a team led by NASA’s Donald Heath, BUV was the first space-based instrument to measure the total amount of ozone in the Earth’s atmosphere. “Don was really sweating the Nimbus-4 launch because his MUSE instrument on one of the previous Nimbus satellites ended up in the Pacific Ocean offshore from Vandenberg Air Force Base,” said Arlin Krueger, technical officer for the BUV science team. “That instrument was recovered from the ocean floor and sat on his filing cabinet for years as a reminder that risks are big part of the NASA experimenter’s life.”

Fortunately, the launch went smoothly. The BUV performed well and demonstrated a new way to measure total column ozone. This led to the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7. The ozone data it collected gave researchers baseline measurements that, in the mid-1980s, helped them recognize that a troubling hole in the ozone layer had opened up.

The global recognition of the destructive potential of CFCs soon led to the 1987 Montreal Protocol, a treaty phasing out the production of ozone-depleting chemicals. Since then, scientists have begun to see definitive proof of ozone recovery.

You can find the latest data and imagery of the status of the ozone hole on NASA’s Ozone Watch website. You can read more about the role that satellites played in the discovery of stratospheric ozone depletion here.

And Then There Were Eight

April 7th, 2020 by Mike Carlowicz

There have been two rounds of voting in Tournament Earth 2020, and two rounds of stunning upsets. Only two of the top eight seeds made it through. Night Lights? Snuffed out. Colorado River? Dried up. Caspian ice? Melted. Aerosols? Cleaned out. A river of tea? Gone cold. Dark side of the Moon? Someone broke the record. Iconic Earthrise? Didn’t make it to dawn.

Every time we run one of these tournaments, we are surprised by what catches the eyes of our readers. It is time to surprise us again. Cast your votes now in round three to pick the best four of the Earthly 8. Voting ends on April 13 at 9 a.m. U.S. Eastern Time. Check out the remaining competitors below.

“Past Winners” Bracket: 
Ocean Sand, Bahamas (#5) vs. A View of Earth from Saturn (#2)

In round 1, Ocean Sand garnered the most votes overall and wiped out #4 seed and 2014 champion El Hierro Submarine Eruption, winning by the largest margin of any pairing (81 to 19 percent). In round 2, Sand beat the #1 seed, The Dark Side and the Bright Side, by a 57 to 43 percent margin. 

A View from Saturn garnered the second highest vote total in round 1, besting Blooming Baltic Sea by 77 to 23 percent. In the second round, Saturn beat Sensing Lightning from the Space Station, 60 to 40 percent. In case you didn’t notice, Earth is visible in that Saturn image.


“Home Planet” Bracket:
Twin Blue Marbles (#1) vs. Fire in the Sky and on the Ground (#7)

Twin Blue Marbles is the only #1 seed left in the tournament. In round 1, it captured 71 percent of the vote while besting Auroras Light Up the Antarctic Night. In round 2, Blue Marbles was the top overall vote getter and beat the iconic A Voyager Far from Home by 66 to 34 percent.

Fire in the Sky and On the Ground has pulled off two massive upsets. In round 1, it beat #2 seed Night Light Maps Open Up New Applications, 71 to 29 percent. In round 2, Fire beat the sentimental favorite and oldest image in Tournament Earth, All of You on the Good Earth — the original Blue Marble photo (1968) and the inspiration for the first Earth Day (1970). The voters chose the auroral fire over Apollo 8 fame by 57 to 43 percent.

“Ice and Land” Bracket:
Where the Dunes End (#8) vs. Retreat of the Columbia Glacier (#6)

This bracket pairs two low seeds that knocked off highly ranked opponents. #8 seed Where the Dunes End topped #1 A Curious Ensemble of Wonderful Features in round 1 (63 to 37 percent), then topped #4 Roiling Flows on Holuhraun Lava Field (56 to 44). 

The false-color image Retreat of the Columbia Glacier got 57 percent of the vote to beat Icy Art in the Sanikov Strait in round 1. Round 2 was a close call: Columbia barely eclipsed Antartica Melts Under the Hottest Days on Record (51 to 49 percent).

“Sea and Sky” Bracket:
Atafu Atoll, Tokelau (#8) vs. Raikoke Erupts (#6)

Another pair of Cinderella stories here. Atafu Atoll outclassed #1 seed Some Tea with Your River in round 1 by 75 to 25 percent. In round 2, it collected the second most votes overall, beating #5 Making Waves in the Andaman Sea 62 to 38 percent.

Raikoke erupted in round 1, collecting 72 percent of the vote while beating #3 Awesome, Frightening View of Hurricane Florence. In round 2, the volcanic plume smothered #2 Just Another Day on Aerosol Earth, 61 to 39 percent.

Visit this page to vote in round three.
View the full results here in bracket format.  

March Puzzler

March 31st, 2020 by Kathryn Hansen

Every month on Earth Matters, we offer a puzzling satellite image. The March 2020 puzzler is above. Your challenge is to use the comments section to tell us what we are looking at, where it is, and why it is interesting.

How to answer. You can use a few words or several paragraphs. You might simply tell us the location, or you can dig deeper and explain what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure feature. If you think something is interesting or noteworthy, tell us about it.

The prize. We cannot offer prize money or a trip to Mars, but we can promise you credit and glory. Well, maybe just credit. Roughly one week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the first person to correctly identify the image at the bottom of this blog post. We also may recognize readers who offer the most interesting tidbits of information about the geological, meteorological, or human processes that have shaped the landscape. Please include your preferred name or alias with your comment. If you work for or attend an institution that you would like to recognize, please mention that as well.

Recent winners. If you’ve won the puzzler in the past few months, or if you work in geospatial imaging, please hold your answer for at least a day to give less experienced readers a chance.

Releasing Comments. Savvy readers have solved some puzzlers after a few minutes. To give more people a chance, we may wait 24 to 48 hours before posting comments. Good luck!

Getting an EPIC Perspective

March 20th, 2020 by Adam Voiland

It has been a tough month on Earth. Good news has been scarce. But here’s at least one update ― from one million miles away ― to appreciate.

The Deep Space Climate Observatory (DSCOVR) satellite, which had been out of commission for about nine months due to a technical problem, is fully operational again, according to NOAA. Issues with the satellite’s attitude control system prompted engineers to put the satellite into a “safe hold” in June 2019, but they recently developed a software fix for the problem.

And that means that the satellite’s Earth Polychromatic Imaging Camera (EPIC) is once again taking beautiful full-disk images of our home several times each day. NASA’s EPIC instrument acquired the image of Africa and Europe (above) on March 19, 2020.

Head over to the science team page for EPIC and take a few moments to savor some imagery of our ever-changing planet. If Twitter is more your style, check out @DSCOVRDaily. Look carefully and you’ll see clouds and storm fronts coming and going, plumes of dust or smoke rising and fading, and whole continents greening and browning as the seasons change.

The EPIC view is a potent reminder of something that Frank White, author of The Overview Effect, said recently on a NASA podcast. (The book explores how seeing Earth from space causes many astronauts to dramatically change their outlook on our planet and life itself.)

“[One of the] conclusions they draw is that we are really all in this together,” he said. “Our fate is bound up with people that we may think are really different from [us]. We may have different religions, we may have different politics. But ultimately, we are connected. Totally connected.”