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.
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.
More than 20 years ago, NASA scientist Ralph Kahn authored a column for the Los Angeles Times anticipating the launch of a new satellite — and ultimately a whole fleet of satellites — that would study Earth.
“We want a picture of Earth that is more specific about what is happening to the climate, which after all is what makes the planet habitable,” he wrote. And that picture needed to be rich with detail. “Precisely where are deserts encroaching on grasslands? In what regions is it raining more than usual? Exactly how much are glaciers shrinking, and at what rate is the sea level rising?” he asked.
“About every seven weeks, the satellite archives will receive as much data from EOS-AM as are held in all the volumes of the Library of Congress. And the EOS-AM satellite alone is supposed to keep pouring numbers down from the sky, relentlessly, for at least six years,” Kahn wrote.
Amazingly, all those numbers from Terra continue to pour down 20 years later. Over time, the flood of data from Terra and several other satellites has turned into scientific discoveries. Bit by bit, the questions Kahn initially posed in his column have been answered.
Seven million years ago, some truly spectacular creatures roamed the woodlands of East Africa. There was a moose-like giraffe called Shiva’s beast. There were giant buffalo with horns wider than the animals were tall. And the lumbering creatures known as anthracotheres defy easy categorization.
“Whenever I ask colleagues who study anthracotheres how they describe them, they always say: hippo-pig,” laughed Tyler Faith, curator of archaeology at the Natural History Museum of Utah. As for the buffalo: “This was a horn span of 3 meters (10 feet). I mean this was an awesome buffalo.”
These and several dozen variations of more recognizable African megaherbivores — elephants, rhinos, hippos, and giraffes — all went extinct within the past several million years. For decades, archaeologists have pinned the blame on early humans, particularly Homo erectus, a species that emerged 2 million years ago, walked upright, and had a body plan similar to modern humans. Since Homo erectus made stone weapons and was capable of butchering large game, many archaeologists assumed that it hunted Africa’s megaherbivores into extinction — much like the fossil record suggests Homo sapiens (modern humans) did to the large mammals of North and South America some 11,000 years ago.
But nobody rigorously tested whether this “overkill hypothesis” fit with the fossil record. “Speculation had been repeated often enough that it just graduated into fact; it became the truth,” Tyler explained during a recent colloquium at NASA’s Goddard Space Flight Center. To check more rigorously, Tyler and colleagues analyzed fossil assemblages from 101 sites in Eastern Africa.
What they found was a surprise. Megaherbivores began disappearing about 4.6 million years ago — long before Homo erectus came on the scene (1.8 million years ago). And there was no increase in the rate of extinctions even when Homo erectus and butchering showed up in fossil records.
However, when the researchers looked at some key indicators of past environmental conditions, they found one key change — the expansion of grasslands — lined up with the extinctions almost perfectly. Five million years ago, classic open grasslands like today’s Serengeti Plain did not exist in East Africa. Trees and shrubs were a much more dominant part of that African landscape then, explained Tyler.
But as carbon dioxide levels declined, mainly due to orbital variations and changes in the amount of Earth covered by ice, forests retreated and grasslands became dominant. Since many of the megaherbivores fed mainly on woody vegetation, they likely faded away along with their food sources. Meanwhile, other familiar species thrived. The ancestors of wildebeest, hartebeests, Thompson gazelles, oryx, plains zebras, and warthogs — all grazers that live in open habitats — proliferated.
Faith’s bottom line is that it is time to stop blaming Homo erectus for something they didn’t do. “In the search for ancient hominid impacts on ancient African ecosystems, we must focus our attention on the one species known to be capable of causing them – us, Homo sapiens, over the past 300,000 years,” he said.
The March–April 2019 issue marks the thirtieth anniversary of the release of the first issue of The Earth Observer newsletter in March 1989. Alan Ward has spent much of his career working on this publication—including 13 years as Executive Editor—and has written a reflection to mark this milestone. The following version has been edited for length. You can read the full story here.
Spurred on by the successes of pioneers in satellite remote sensing, in the early-to-mid-1980s a concept emerged to obtain coordinated Earth observations from space. The earliest designs envisioned having several large platforms in orbit, each carrying many instruments, that could be serviced via the Space Shuttle, akin to how the Hubble Telescope was reserviced. However, that approach eventually morphed into the present fleet of small-to-mid-sized satellites launched on unmanned rockets: e.g., Terra, launched on an Atlas IIAS rocket; Aqua and Aura, both launched on Delta II rockets. The idea was given a name: the Earth Observing System (EOS).
Making EOS a reality would require a fundamental shift in how scientists studying Earth approached their research. Traditionally, individual science disciplines tended to focus on their own areas of expertise, and only occasionally worked together. The idea behind EOS was to study the Earth as a system of interrelated systems—an approach that came to be known as Earth System Science. Functionally, that meant that scientists from different disciplines would need to collaborate much more frequently than they had in the past.
In short, EOS was a grand vision: that we’d someday have a fleet of satellites (along with complementary ground observations and computing systems) continuously taking the pulse of our home planet and sending back large amounts of data—and that scientists would come together to work on related topics. But just how would it all work in practice? No one knew for sure back then. Ask anyone who attended early EOS meetings what they were like and they are likely to use words such as “chaotic” and “challenging” to describe them. In an article he wrote for The Earth Observer, Darrel Williams [former Project Scientist for Landsat 7, currently Chief Scientist at Global Science & Technology, Inc.] recalled that Pier Sellers once described the overall experience of trying to take EOS from idea to reality as being, “…like putting socks on an octopus.”
Sellers definitely had a unique way with words. Whatever creative metaphor one might use to describe it, there is no doubt that those first EOS investigators had huge challenges before them! Not only did they have to work out the details of the flight hardware and computing systems for EOS almost from scratch, but they also had to figure out the practical details of how they would actually work together.
As challenging as developing space flight hardware was (and still is), at that time there was an even larger logistics issue that needed to be addressed. A huge program involving hundreds of researchers strewn all over the nation—and eventually the globe—was trying to get off the ground, and the participants needed the means to communicate. The Internet, which we take for granted today, was in its infancy at that time. If you wanted to get the word out about upcoming meetings, results from those meetings, announcements, and the like, print media was still the way to go. Enter The Earth Observer!
Thirty Years Chronicling NASA Earth Science
Space does not permit the full story of the intimately interconnected history of the evolution of The Earth Observer and EOS to be repeated here. For this context, it suffices to say that the idea, or concept of EOS faced a difficult journey—and evolved a great deal—before it became what it is today, and that, from its inception, The Earth Observer has chronicled that story.
By the time I made my first contribution to The Earth Observer in 2001, the EOS Earth observing satellite fleet was beginning to take shape. Terra had been launched only a couple years earlier and the other flagship missions (Aqua and Aura) would follow in the next three years. During my tenure, I’ve watched the EOS Program come of age. The Earth Observer has chronicled the establishment and now graceful aging of members of NASA’s Earth-observing fleet of satellites, and has also reported on airborne and ground-based sensors.
We continue to report on NASA Earth Science as we move beyond the EOS era into the Suomi NPP and JPSS era, and into other endeavors such as Decadal Survey missions, including the Earth Venture element. We’ve reported on the launches of new (or recently launched) missions along the way, as well as on the remarkable scientific achievements of existing platforms as, one by one, they exceeded their planned mission lifetimes—often by many years—and celebrated a decade or more in orbit.
I noted earlier that EOS wasn’t simply a satellite-based program. The Earth Observer has also reported on the complementary ground elements, describing results from field campaigns and other ground-based observation programs over the years.The Earth Observer has also published feature articles on more-general topics, such as Earth Science Mission Operations, responsible for keeping the fleet flying safely, and Earth Science Data Operations, which includes the EOS Data and Information System, better known as EOSDIS.
Perhaps the series I take the most personal pride in is our Perspectives on EOS series, which ran from 2008 through 2011. It really didn’t begin with a series in mind; it started with an article that I wrote for the newsletter’s twentieth year, and grew organically into a compendium of recollections and memories from key members of the EOS program. It is often said that history is the telling of a personal story, and that was certainly true with these articles, as the storytellers had actually lived them.
It has been my honor to serve as executive editor for a baker’s dozen of years, and I look forward to seeing what comes next for The Earth Observer as we begin our fourth decade. I think it’s been a good run so far—but I hope our best is yet to come!
On April 29, 1999, NASA Earth Observatory (EO) started delivering science stories and imagery to the public through the Internet. So much has changed in those 20 years…
+ In 1999, about 3 to 5 percent of the world had Internet access. About 41 percent of American adults used the World Wide Web, most often to look at the weather. Today an estimated 56 percent of the world’s population (4.3 billion people) are active on the Internet.
+ At the end of the 20th century, all EO readers came to us through a computer, mostly desktops. One third of them were connecting via dial-up modem. Today, about 40 percent of our audience arrives to the web site via mobile phones and tablets on public wifi and cellular networks. Yet even now, 65,000 of our most loyal followers subscribe to our newsletters. Many others subscribe to our RSS feeds.
+ In 1999, “social” media mostly consisted of chatrooms and newsgroups. Even by 2005, only 5 percent of Americans were using social media. Today about 69 percent of adults use social media, and people are just as likely to see Earth Observatory content on social platforms as on our web site. Ten million people follow EO and NASA Earth science on Facebook, with 1.3 million more on Twitter, and 500,000 on Instagram.
+ When EO launched, images from Earth science satellites were generally available about a month after acquisition. Public access to science data and imagery was extremely limited, highly filtered, and sometimes required a fee. Two decades later, many NASA Earth science observations are available freely on the web within hours of acquisition.
+ On our first day online, the site got 400 pageviews–most of them were likely colleagues and relatives. Today we get about 50,000 views per day.
+ In our first year, we published 35 “Images of the Week” and 9 feature stories. By 2001, we started delivering an Image of the Day. Since launch, we have published more than 6,900 Images of the Day, 8,300 natural hazards images, and 450 features and videos. Yes, more than 15,000 image-driven stories, and all of them are still available in our archive.
+ In 1999, two members of our staff were in elementary school and three were in high school. The readers of EO Kids were not born yet.
The technology of science and the Internet has changed in a generation, and our site has evolved and grown with the changes. But our core values have not changed. You find us on more platforms and with some new approaches, but you can still count on us to deliver beautiful, newsworthy, interesting, and scientifically important images and stories. Our editorial team has more than 110 years of experience in science communication and data visualization, and we bring that depth of knowledge to every story, 365 days a year.
None of this would be possible without the many scientists, engineers, communicators, data hounds, patrons, and friends inside and outside of NASA who review our work, tip us off to stories and images, share their scientific insights, and inspire and challenge us. Thank you.
As we celebrate our 20th year, we are going to share some looks back and some looks ahead. In the next twelve months, look for…
EO on This Day – a chance to see some of the most memorable Images released on each day of the calendar year
If you have been with us for many (or all) of our 20 years, thank you. We have some of the most engaged, challenging, and thoughtful readers on the planet, and we work hard to live up to your trust and interest. If you are new to the site, bring a friend. We have 15,000 stories about Earth to share, with more being added every day.
The shiny metallic orb hanging in the Earth sciences building at NASA’s Goddard Space Flight Center looks a lot like a fixture you might find at a modern home décor store. But this mid-century marvel is not for sale. It is a restored flight backup of Vanguard II, Earth’s first weather satellite.
The satellite model was hung this week as a reminder of the people who helped build the foundation for making space-based observations of Earth. Paul Newman, chief scientist for Earth science at NASA Goddard, described the satellite:
“Vanguard II was the world’s first meteorological satellite. Developed at the U.S. Naval Research Laboratory (NRL), it was successfully launched by newly formed NASA on February 17, 1959. Vanguard carried two photocells that could scan cloud cover as the satellite rotated in its orbit around the Earth. Unfortunately, the 3rd stage SLV-4 launch vehicle burn caused a precession in the satellite that made the data unusable.”
“While the now silent Vanguard II continues to orbit the Earth, its back-up brother has been restored and mounted in the Goddard Space Flight Center’s Earth Sciences building’s atrium—a fitting resting place amongst the scientists and meteorologists who monitor and study our Earth.”
Some of those scientists, and five retirees from the original NRL Vanguard II team, gathered on April 15, 2019, at NASA Goddard to celebrate the satellite’s 60th anniversary. Angelina Callahan, historian at the U.S. Naval Research Laboratory, reflected on the historical importance of the Vanguard era. From building satellites and their launching vehicles, to putting satellites in orbit and tracking them, the achievements of the program helped pave the way for satellite missions that followed.
The reflection was also a study on how much has changed. Ron Gelaro, an atmospheric scientist at NASA Goddard, discussed weather prediction in the modern satellite era. Vanguard II carried two photocells and weighed just 21 pounds. The Aqua satellite—launched in 2002 to collect information on Earth’s water systems—carries six instruments and weighs more than 6,000 pounds. Gelero noted, however, that satellites are starting to trend back toward smaller vehicles, such as constellations of microsatellites.
The amount of observations available for understanding weather and climate have also skyrocketed over the decades. For example, MERRA-2 is a reanalysis project at NASA Goddard that combines satellite measurements of temperature, moisture, and winds in the GEOS model. In 1980, MERRA assimilated 175,000 observations for every six-hour period. That number in 2018 neared 5 million observations.
According to NRL: “The scientific experiments flown on the Vanguard satellites increased scientific knowledge of space and opened the way for more sophisticated experiments. Vanguard was the prototype for much of what became the U.S. space program.”
In fact, about 200 scientists and engineers from the Vanguard program moved from NRL to the newly formed NASA in 1958—forming the core of NASA Goddard. You can read more about Vanguard here.
On February 27, 2014, a Japanese rocket launched NASA’s latest satellite to advance how scientists study raindrops from space. The satellite, the Global Precipitation Measurement (GPM) Core Observatory, paints a picture of global precipitation every 30 minutes, with help from its other international satellite partners. It has provided innumerable insights into Earth’s precipitation patterns, severe storms, and into the rain and snow particles within clouds. It has also helped farmers trying to increase crop yields, and aided researchers predicting the spread of fires.
In honor of GPM’s fifth anniversary, we’re highlighting some of our favorite and most unique Earth Observatory stories, as made possible by measurements taken by GPM.
The Second Wettest
October in Texas Ever
In Fall 2018, storm after storm rolled through and dumped
record rainfall in parts of Texas. When Hurricane Willa hit Texas around
October 24, the ground was already soaked. One particularly potent cold front
in mid-October dropped more than a foot of rain in areas. By the end of the
month, October 2018 was the second wettest month in Texas on record.
GPM measured the total amount of rainfall over the region from October 1 to October 31, 2018. The brightest areas reflect the highest rainfall amounts, with many places receiving 25 to 45 centimeters (10 to 17 inches) or more during this period. The satellite imagery can also be seen from natural-color satellite imagery.
Observing Rivers in
With the GPM mission’s global vantage point, we can more
clearly see how weather systems form and connect with one another. In
this visualization from October 11-22, 2017, note the long, narrow
bands of moisture in the air, known as “atmospheric rivers.” These
streams are fairly common in the Pacific Northwest and frequently bring much of
the region’s heavy rains and snow in the fall and winter. But this atmospheric
river was unusual for its length—extending roughly 8,000 kilometers (5,000
miles) from Japan to Washington. That’s about two to three times the typical
length of an atmospheric river.
Since atmospheric rivers often bring strong winds, they can force moisture up and over mountain ranges and drop a lot of precipitation in the process. In this case, more than four inches of rain fell on the western slopes of the Olympic Mountains and the Cascade Range, while areas to the east of the mountains (in the rain shadow) generally saw less than one inch.
Increasing Crop Yield
for Farmers in Pakistan
Knowing how much precipitation is falling or has fallen is
useful for people around the world. Farmers, in particular, are interested in
knowing precipitation amounts so they can prevent overwatering or underwatering
The Sustainability, Satellites, Water, and Environment (SASWE) research group at the University of Washington has been working with the Pakistan Council of Research in Water Resources (PCRWR) to bring this kind of valuable information directly to the cell phones of farmers. A survey by the PCRWR found that farmers who used the text message alerts reported a 40 percent savings in water. Anecdotally, many farmers say their income has doubled because they got more crops by applying the correct amount of water.
The map above shows the forecast for evapotranspiration for October 16-22, 2018. Evapotranspiration is an indication of the amount of water vapor being removed by sunlight and wind from the soil and from plant leaves. It is calculated from data on temperature, humidity, wind speed, and solar radiation, as well as a global numerical weather model that assimilates NASA satellite data. The team also looks at maps of precipitation, temperature and wind speed to help determine crop conditions. Precipitation data comes from GPM that is combined with ground-based measurements from the Pakistan Meteorological Department.
Precipitation can drastically affect the spread of a fire. For
instance, if a region has not received normal precipitation for weeks or
months, the vegetation might be drier and more prone to catching fire.
NASA researchers recently created a model that analyzes various weather factors that lead to the formation and spread of fires. The Global Fire Weather Database (GFWED) accounts for local winds, temperatures, and humidity, while also being the first fire prediction model to include satellite–based precipitation measurements.
The animation above shows GFWED’s calculated fire danger around the world from 2015 to 2017. The model compiles and analyzes various data sets and produces a rating that indicates how likely and intense fire might become in a particular area. It is the same type of rating that many firefighting agencies use in their day–to–day operations. Historical data are available to understand the weather conditions under which fires have occurred in the past, and near–real–time data are available to gauge current fire danger.
In this mountainous country of Nepal, 60 to 80 percent of the annual precipitation falls during the monsoon (roughly June to August). That’s also when roughly 90 percent of Nepal’s landslide fatalities occur. NASA researchers have designed an automated system to identify potential landslides that might otherwise go undetected and unreported. This information could significantly improve landslide inventories, leading to better risk management.
The computer program works by scanning satellite imagery for signs that a landslide may have occurred recently, looking at topographical features such as hill slopes.
The left and middle images above were acquired by the Landsat 8 satellite on September 15, 2013, and September 18, 2014—before and after the Jure landslide in Nepal on August 2, 2014. The image on the right shows that 2014 Landsat image processed with computer program. The red areas show most of the traits of a landslide, while yellow areas exhibit a few of the proxy traits.
The program also uses data from GPM to help pin when each landslide occurred. The GPM core satellite measures rain and snow several times daily, allowing researchers to create maps of rain accumulation over 24-, 48-, and 72-hour periods for given areas of interest—a product they call Detecting Real-time Increased Precipitation, or DRIP. When a certain amount of rain has fallen in a region, an email can be sent to emergency responders and other interested parties.
The GPM Core
Observatory is a joint satellite project by NASA and the Japan Aerospace
Exploration Agency. The satellite is part of the larger GPM mission, which
consists of about a dozen international satellite partners to provide global
observations of rain and snow.
On February 12, 1809, Charles Robert Darwin was born in England in the town of Shrewsbury. The famed naturalist, geologist, and biologist is best known for his 19th century expedition to the Galápagos Islands, which inspired revolutionary insights about evolution and natural selection. Lesser known is that the expedition to the Galápagos was just one part of a much longer journey. The Second Voyage of the HMS Beagle brought Darwin and his fellow travelers to South America, Australia, Africa, and several islands in between. Here are a few interesting places where the HMSBeagle stopped that we have covered in earlier stories.
January 1832: The Dusty Canary Islands, Tenerife
The crew of the Beagle was denied landing on Tenerife because of fears they might be carrying cholera. The Operational Land Imager (OLI) on Landsat 8 acquired this image of the island on January 25, 2016.
Darwin was struck by the intensity of the dust in this area. “The atmosphere is generally very hazy, chiefly due to an impalpable dust, which is constantly falling, even on vessels far out at sea,” he wrote. “It is produced, as I believe, from the wear and tear of volcanic rocks, and must come from the coast of Africa.”
Christmas 1832: Cape Horn, South America
Southwest of Cape Horn at the southern tip of South America, the ocean floor rises sharply. Along with the potent westerly winds that swirl around the Furious Fifties, this pushes up massive waves with frightening regularity. Add in frigid water temperatures, rocky coastal shoals, and stray icebergs—which drift north from Antarctica across the Drake Passage—and it is easy to see why the area is known as a graveyard for ships. In his journal, Darwin described the harrowing journey as the explorers tried to round the Horn just before Christmas.
September 1835: The Galapagos
The Galapagos archipelago includes more than 125 islands, islets, and rocks populated by a diversity of wildlife. Charles Darwin’s book, The Voyage of the Beagle, cast a spotlight on the Galapagos, which he called “a little world within itself, or rather a satellite attached to America, whence it has derived a few stray colonists.” It was this little world that would revolutionize scientific understanding of biology and lead to Darwin’s On the Origin of Species, which would come to be known as the foundation of evolution.
November 1835: The Coral Reefs of Tahiti
On this stopover, Darwin had a chance to explore coral reef.
“We paddled for some time about the reef admiring the pretty branching Corals,” he wrote. “It is my opinion, that besides the avowed ignorance concerning the tiny architects of each individual species, little is yet known, in spite of the much which has been written, of the structure and origin of the Coral Islands and reefs.”
The Enhanced Thematic Mapper Plus on the Landsat 7 satellite captured this natural-color image of Tahiti on July 11, 2001. This island is part of a volcanic chain formed by the northwestward movement of the Pacific Plate over a fixed hotspot.
1836: Pondering Phytoplankton Near Australia
All the sea travel offered plenty of time to observe and ponder the intricacies of phytoplankton.
“My attention was called to a reddish-brown appearance in the sea. The whole surface of the water, as it appeared under a weak lens, seemed as if covered by chopped bits of hay, with their ends jagged,” he wrote. “These are minute cylindrical, in bundles or rafts of from twenty to sixty in each…Their numbers must be infinite: the ship passed through several bands of them, one of which was about ten yards wide, and, judging from the mud-like color of the water, at least two and a half miles.”
On August 9, 2011, the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite captured this image of a similar band of brown between the Great Barrier Reef and the Queensland shore. Though it’s impossible to identify the species from satellite imagery, such red-brown streamers are usually trichodesmium. Sailors have long called these brown streamers “sea sawdust.”
November 22nd, 2018 by Adam Voiland & Michael Carlowicz
Editor’s Note: We have highlighted the story of the Pilgrims and Thanksgiving several times over the years. Here are some of those pieces in one convenient place.
First stop, Holland. Image credit: NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey.
Most school children in America learn about the Pilgrims—the group of English settlers who endured a harrowing journey to the New World in 1620 on the Mayflower. It is sometimes overlooked, however, that Plymouth was not the first stop—nor the intended destination—for this congregation of religious separatists from the town of Scrooby in the English county of Nottinghamshire.
Before ever setting foot in North America, the Pilgrims spent several years living in Leiden, a city in the Netherlands. Most of the hundred or so people in the congregation lived in one-room cottages near Leiden University, in the shadow of the Pieterskerk, the oldest church in the city.
About a decade after they arrived, the congregation decided it was time to move. Tough economic conditions in Leiden meant few new recruits from England were willing to join them; Dutch culture was thought to be a bad influence on the children; and there was a looming possibility that Holland would go to war with Spain, a leading Catholic power.
Leaving Leiden University. NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey.
Leiden was a city of many waterways, so when the Pilgrims were ready to leave in July 1620, they boarded several small boats on the Rapenburg Canal (near the university). This narrow canal fed into the larger Vliet Canal, which flows from Leiden toward Delft.
From there, they made their way back to England, where they struggled for a few months trying to repair a leaking ship. After abandoning that ship, they finally set sail for the New World on September 6, 1620, knowing they had to cross nearly 3,000 miles of open ocean.
The North Atlantic can be treacherous. Image credit: NASA Earth Observatory image by Jesse Allen and Robert Simmon, using VIIRS data from the Suomi National Polar-orbiting Partnership.
The original destination: the mouth of the Hudson River. NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey.
The first half of the two month journey proved to be smooth and uneventful. But in October, they encountered a series of storms that turned the sea into a writhing cauldron. During one particularly bad storm, the ship nearly capsized.
Their intended destination was the northern edge of Virginia Colony, which at the time stretched from to the mouth of the Hudson River. However, the storms blew the Pilgrims off course toward Cape Cod in Massachusetts.
Provincetown, Massachusetts. NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey.
When they realized this, they contemplated heading south. However, they were wary of the shallow waters and shoals east and south of Cape Cod and Nantucket—waters full of the sandy, rocky outwash from ancient glaciers. They sailed instead around the northeastern tip of the Cape and on November 21, 1620, dropped anchor just off the shores of modern-day Provincetown. While resting in that harbor, they composed and signed the first self-governing document in American history, the Mayflower Compact.
Over the coming weeks, they made first contact with Native American people, likely the Nauset tribe. First Encounter Beach in Eastham marks the reported location of a skirmish between the colonists and the tribe. The Pilgrims eventually sailed across Cape Cod Bay and settled in Plymouth.
First Encounter Beach. NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey.
It was in Plymouth where the Pilgrims celebrated the first Thanksgiving, a three-day harvest celebration that included feasting, games, and military exercises.
While there continues to be debate among historians about the circumstances and influences that led to the first Thanksgiving, there is evidence that the roots of the tradition might be traced back to Leiden. During their time in the city, the Pilgrims would have experienced a celebratory thanksgiving service and festival that was held each year on October 3 to mark the 1574 end of the Spanish siege of the city.
Crossing Cape Cod Bay brought the Pilgrims to Plymouth. This astronaut photograph was acquired on November 7, 2007.
Betty Fleming, a cartographer, helped discover tiny Landsat Island with satellite imagery in the 1970s. Photo courtesy of Betty Fleming.
At age 86, Betty Fleming was on a cruise along the Labrador Coast of Canada. The ship was approaching an area all too familiar to her: a small island she helped discover when she was a cartographer for the Surveys and Mapping branch in Canada’s Department of Energy, Mines, and Resources.
“I want to tell you about a small off-shore island that we will be passing as we round the top end of Labrador on this trip,” wrote Fleming in her notes, which she used to deliver a presentation to her 90 fellow passengers on her leisure Adventure Canada cruise. “Landsat Island has garnered quite a bit of attention since it was first mapped in 1976. Don’t expect to see it though, as it is in the middle of an area of reefs and shoals.”
More than 45 years ago, Fleming was surveying the same waters, but via satellite imagery from the Landsat 1 satellite. Earth Resources Technology Satellite 1, later named Landsat, was an early Earth-sensing satellite launched by the United States. Before the satellite even launched, Canada built a receiving station to receive the satellite data for the orbits over Canada.
Aerial image of Landsat Island taken by David Gray on August 2, 1997.
This satellite image of Landsat Island captured on July 15, 2014, by the Operational Land Imager (OLI) on Landsat 8. The island spans no more than a pixel or two. Image credit: NASA Earth Observatory/Joshua Stevens
The 1970s was an exciting time for Fleming, as acquiring and analyzing satellite imagery was new and thrilling. As Canada received imagery from Landsat roughly every two weeks, Fleming had the task of seeing where the Department of Energy, Mines and Resources might use the imagery for mapping Canada, particularly for mapping wilderness areas and building new roads. At the time, the hydrographic charts for the northern coast of Labrador were also quite old and based on surveys by the British Navy in 1911 and on questionable notes made by passing sailors.
In those early Landsat days, Fleming was inspecting imagery of the coast from Landsat 1 when she spotted several small white specks. At first, she assumed they were icebergs, but some of the specks kept appearing in the same position over several images. She knew some of them had to be permanent features.
Landsat coverage of the survey area showing the overlap of the satellite images. The land area tended to be cloud-covered, forcing the selection of control points to the narrow coastal band as shown. Image courtesy of Betty Fleming.
She passed the information to the Canadian Hydrographic Survey Division, which sent the CCS Baffin to visit about 20 such locations in the following summer. Most of the locations were insignificant rocks partly submerged in the sea—Fleming called them “rocks awash”– but one of the spots was actually an island. Fleming and the Landsat satellite had discovered an uncharted Canadian island. It eventually became known as Landsat Island.
CSS Baffin survey of the coast of Labrador from 59°15’N to 60° 25’N during 1976 to chart offshore features and check reported rocks. Image courtesy of Betty Fleming.
Landsat Island was not too spectacular. It was rocky and only about half the size of a football field. From a satellite perspective, though, this island was notable because of its size – or rather lack of it. Earth science researchers were impressed that a satellite could detect such a small feature. The island was also interesting, says Fleming, because it had a bearing on the international boundary: it was the most easterly point of land at that part of the coast.
Fleming has never seen Landsat Island and does not expect to. She never went out on the ships or helicopters that were sent to verify the existence of the island. That section of the Labrador coast is “very dangerous,” and her tourist cruise in 2011 is probably the closest she is going to get to the place she discovered.
But that doesn’t faze her. Her accomplishments go beyond one island. Before her stint analyzing Landsat data, she was a pilot and camera operator. She studied at the newly formed Netherlands International Training Centre for Aerial Photography and Earth Sciences and became a specialist on the application of aerial photography to photogrammetric mapping—using photographs to measure and map areas. She also instituted a index map where images could be ordered by orbit number and image number, which was used in Canada.
Then there was simply being a working woman from the 1950s to 1980s, which Fleming says is a story in itself. As a married woman, she too-often ran into people who told her “You’ll leave to have a baby,” or “You’ll take a job from a man.”
When she chose to enter the all-male Surveys and Mapping Department, she had an entry level job at which they hired boys out of high school—despite the fact she had a university degree, post-graduate training, and experience in the aerial survey business. She always used the name “E.A. Fleming” when she prepared a technical paper because “using the name Elizabeth on any technical paper would have been a kiss of death. It would immediately be dropped in the editor’s waste basket without opening it.” She won several awards for her published papers, much to the chagrin of one man who did not find out she was a woman until she accepted an award.
“It took me 20 years to get to the level I should have been hired at, but that doesn’t change the fact that I really enjoyed my work,” wrote Fleming.
After a 30 year-long career in aerial photography and mapping and two happy marriages, Fleming is now retired at the age of 93 and resides in Ottawa, Canada.