1. Global View of the Arctic and Antarctic on September 21, 2005

    In support of International Polar Year, this matching pair of images showing a global view of the Arctic and Antarctic were generated in poster-size resolution. Both images show the sea ice on September 21, 2005, the date at which the sea ice was at its minimum extent in the northern hemisphere. The color of the sea ice is derived from the AMSR-E 89 GHz brightness temperature while the extent of the sea ice was determined by the AMSR-E sea ice concentration. Over the continents, the terrain shows the average land cover for September, 2004. (See Blue Marble Next Generation) The global cloud cover shown was obtained from the original Blue Marble cloud data distributed in 2002. (See Blue Marble:Clouds) A matching star background is provided for each view. All images include transparency, allowing them to be composited on a background.

    Story Credits:


    Cindy Starr (GST) (Lead) 

    Ronald Weaver (University of Colorado) 
    NASA/Goddard Space Flight Center Scientific Visualization Studio The Blue Marble data is courtesy of Reto Stockli (NASA/GSFC).
  2. Hurricane Odile

    At about 10:45 p.m. Mountain Daylight Time (MDT) on September 14, 2014, Hurricane Odile made landfall as aCategory 3 storm near Cabo San Lucas, Mexico. According to the U.S. National Hurricane Center, Odile arrived with wind speeds of 110 knots (204 kilometers or 127 miles per hour). The storm tied Olivia (1967) as the strongest hurricane to make landfall in the state of Baja California Sur in the satellite era.

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color view of the storm at about noon MDT on September 14, when it was still southeast of the Baja California peninsula. Unisys Weather reported that the Category 4 storm had maximum sustained wind speeds of 115 knots (213 kilometers per hour) at the time.

    Odile had weakened to a Category 2 hurricane by 6 a.m. MDT on September 15. The storm was expected to continue weakening as it moved up the peninsula and over the area’s rough terrain, according to weather blogger Jeff Masters. Meteorologists noted that while damaging winds posed the biggest threat in the short term, inland areas of the U.S. Southwest could face heavy rainfall by September 16.

    The rain expected from Odile came one week after the U.S. Southwest experienced flash floods from the remnants of Hurricane Norbert. According to weather and climate blogger Eric Holthaus, those floods did little to relieve the area’s ongoing drought.

    NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Kathryn Hansen.

    Instrument(s): Terra - MODIS
  3. Star-Spangled City

    The song is familiar to every American, but the moment and place where it was composed are less so.

    On April 24, 2014, the Operational Land Imager (OLI) on Landsat 8 captured this view of Baltimore, Maryland, and its harbor. Fort McHenry and its star-shaped ramparts—the place where “that star-spangled banner yet wave[d],” on September 14, 1814—stand at the entrance to the city’s Inner Harbor. The area was a pivotal battleground in the War of 1812.

    In September 1814, British naval and ground forces advanced on the city of Baltimore, emboldened by the August 24 burning of The White House and the Capitol building in Washington, D.C. On September 12, British forces landed at North Point, 5 miles (8 kilometers) southeast of Baltimore (just off the lower right of this image), and engaged American troops in several small battles. By September 13, the land forces approached the city of Baltimore but were repelled by U.S. Army and Maryland militia forces assembled behind a mile of earthworks and trenches along Hampstead Hill—near what is now known as Patterson Park (image top center).

    On the morning of September 13, British naval vessels set up positions roughly at the point where this image is labeled Baltimore Harbor. They began a 25-hour bombardment of Fort McHenry, staying far enough offshore to hit the fort with rockets and cannonballs but out of the range of American artillery. Unable to subdue the fort, and hampered by several merchant vessels that were intentionally sunk in the harbor, the British forces ended their attack on the morning of September 14.

    The Battle of Baltimore moved a young American lawyer and negotiator to write a song entitled “Defense of Fort M’Henry.” Francis Scott Key had spent the night of September 13 on a British vessel in the Patapsco River, working to secure the release of American prisoners of war. Local legend in Maryland holds that the HMS Tonnant was anchored roughly where the Key Bridge is now located, giving Key a direct view toward Fort McHenry and “the rockets’ red glare, the bombs bursting in air,” that “gave proof through the night that our flag was still there.” On September 14, a clean 30 by 42 foot American flag was raised over Fort McHenry “by the dawn’s early light.”

    Key’s four-verse song was published on September 20, 1814, in the Baltimore Patriot and the Advertiser. The battle hymn was eventually renamed “The Star-Spangled Banner,” and was declared the national anthem in 1931.

    Beyond its pivotal role in the War of 1812, Baltimore has long been an important sea port on the East Coast of the United States, particularly because of its proximity by road and rail to inland agricultural and industrial hubs in the Midwest. Situated on the Chesapeake Bay, the city is now home to more than 600,000 residents. According to some media reports, nearly one-quarter of the jobs in the Baltimore area are related to science, technology, engineering, or mathematics. It is home to the Space Telescope Science Institute, the operations center for theHubble Space Telescope.

    1. References and Related Reading

    2. Baltimore Business Journal (2014, July 1) STEM workers in demand in Baltimore, Brookings report says. Accessed September 12, 2014.
    3. National Park Service Fort McHenry. Accessed September 12, 2014.
    4. Smithsonian National Museum of American History (2014) The Star-Spangled Banner. Accessed September 12, 2014.
    5. Star-Spangled 200 (2014) War of 1812 Interactive Map. Accessed September 12, 2014.
    6. Star-Spangled 200 (2014) Maryland War of 1812 Bicentennial. Accessed September 12, 2014.

    NASA Earth Observatory image by Jesse Allen, using Landsat data provided by the U.S. Geological Survey. Caption by Michael Carlowicz.

    Instrument(s): Landsat 8 - OLI
  4. Roiling Flows on Holuhraun Lava Field

    As an island in the moist, atmospherically turbulent North Atlantic, Iceland is often shrouded in cloud cover and hard to observe from space. And lately, the island is making some of its own cloud cover, as the Earth has split open between the Bardarbunga and Askja volcanoes and spewed lava and hot gas. The view of the Holuhraun lava field has been spectacular from the ground and from low-flying aircraft. Infrared imaging makes the view spectacular from space, too.

    On September 6, 2014, the Operational Land Imager (OLI) on Landsat 8 captured this view of the ongoing eruption. The false-color images combine shortwave infrared, near infrared, and green light (OLI bands 6-5-3). Ice and the plume of steam and sulfur dioxide appear cyan and bright blue, while liquid water is navy blue. Bare or rocky ground around the Holuhraun lava field appears in shades of green or brown in this band combination. Fresh lava is bright orange and red. (Download this large image to see the same area in natural color.)

    “Thermal imagery can be used to determine the extent of the lava flows and the heat loss,” noted Ashley Davies, a Jet Propulsion Laboratory scientist and leader of NASA’s Volcano Sensor Web team. Infrared imagery can help scientists estimate the effusion rate—the rate at which lava is pouring out of the Earth—as well as the sulfur dioxide content of the plume. “And high resolution imagery of this kind allows us to model the dynamics of the emplacement process. In this case, individual vents can be seen feeding separate lava flows that combine into a main channel feeding an expanding lava flow field.”

    By some accounts, Holuhraun has spewed more lava this month than any Icelandic volcano since the 19th century. As of September 9, 2014, the new lava flow was 16 kilometers (10 miles) long and covered about 20 square kilometers (8 square miles), according to the University of Iceland.

    The plume from Holuhraun is rich with sulfur dioxide (SO2), a rotten-smelling gas that can cause respiratory problems in humans and animals. A blue haze of SO2 and aerosols has been observed downwind over several towns and villages in eastern Iceland. Scientists and other observers working near the eruption site have been evacuated several times and cautioned to keep gas masks handy due to noxious gases and shifting winds. Elevated levels of SO2 have been detected as far as Ireland, Greenland, and Scandinavia.

    The University of Iceland and Iceland Met Office have been providing regular updates on Holurhaun and Bardarbunga via Twitter and on their web site.

    NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey. Caption by Mike Carlowicz.

    Instrument(s): Landsat 8 - OLI
  5. Smoke in Yosemite

    People come to Yosemite National Park expecting awe-inspiring views and great camping amidst the park’s granite peaks and forested lowlands. In September 2014, some visitors got much more than that.

    A small wildfire had been burning in Yosemite for weeks before it suddenly quadrupled in size in early September due to strong winds and high temperatures. Park authorities needed helicopters to evacuate dozens of visitors from back-country locations on September 7, 2014, including 85 climbers airlifted from the summit of Half Dome and approximately 100 hikers picked up from campgrounds in Little Yosemite Valley. Several people posted photographs of the evacuation to social media sites as they were being ferried away.

    A NASA satellite orbiting 725 kilometers (450 miles) overhead captured images of the Meadow fire from above on September 7, 2014. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured the top image of wildfire activity in Little Yosemite Valley. Red outlines indicate hot spots where MODIS detected the unusually warm land surface temperatures associated with fires. The lower image was taken by Yosemite National Park staff on September 7, 2014. Half Dome is on the left, with a smoke plume rising from Little Yosemite Valley to its right.

    Lightning first ignited the Meadow fire on July 20. For several weeks, park officials let the small, high-altitude (8,000 feet or 2,440 meters) blaze burn in order to preserve the park’s natural fire patterns and because it posed no threat to public safety, according to The Los Angeles Times. Indeed, the fire had burned just 19 acres (8 hectares) over the first 49 days.

    Then winds surged on September 7 and the Meadow fire suddenly flared up. By September 8, the fire had charred 2,582 acres (1,044 hectares). Though it is large enough to provoke dramatic photographs from the ground, the fire is small compared to California’s largest fires. For comparison, the Happy Camp Complex fire in northern California has burned more than 99,000 acres and was only partly contained as of the same date.

    Visit Worldview, a satellite image-browsing tool maintained by the MODIS Rapid Response Team, to track the fires over time.

    NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC. Photo courtesy of Yosemite National Park. Caption by Adam Voiland.

    Instrument(s): Aqua - MODIS
  6. The Science of Sunglint

    If you look frequently at satellite imagery or astronaut photography, you have probably noticed bright patches of light that can make certain bodies of water gleam with unusual color. (If not, look at these examples in the waters around Cape Cod and the Lesser Antilles, as well as rivers in Brazil.) That gleam is caused by sunglint, an optical phenomenon that occurs when sunlight reflects off the surface of water at the same angle that a satellite sensor views it. The result is a mirror-like specular reflection of sunlight off the water and back at the satellite sensor or astronaut.

    If bodies of water were perfectly smooth, a sequence of nearly perfect reflections of the Sun would appear in a line along the track of the satellite’s orbit. In reality, water surfaces are irregular and often in motion due to waves and currents, so the sunlight gets scattered in many directions and leaves blurry streaks of light in theswaths of satellite data. For instance, notice the strips of sunglint in the mosaic below. All of the data was collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on July 3, 2014.

    The combination of sunglint, wind patterns, and island shapes around Crete and the Aegean islands made for a particularly spectacular scene that day. (See the image at the top of this page.) Although sunglint washes out many features, it also reveals details about the water and atmospheric circulation that are usually hidden. In this case, sunglint exposed wakes caused by north and northwest winds that roughened and smoothed the water surface behind Crete and the other islands.

    The islands create a sort of wind shadow—blocking, slowing, and redirecting air flow. That wind, or lack of it, piles up waves and choppy water in some places and calms the water surface in others, changing how light is reflected. In addition, sunglint revealed what appear to be atmospheric gravity waves downwind of many of the Aegean Islands.

    While sunglint often produces visually-stunning images, the phenomenon can create problems for remote sensing scientists because it obscures features that are usually visible. This is particularly true for oceanographers who use satellites to study phytoplankton and ocean color. As a result, researchers have developed several methods to screen sunglint-contaminated imagery out of data archives.

    Despite the challenges posed by sunglint, the phenomenon does offer some unique scientific opportunities. It makes it easier, for instance, to detect oil on the water surface, whether it is from natural oil seeps or human-caused oil spills. This is because a layer of oil smooths water surfaces.

    NASA images courtesy LANCE/EOSDIS MODIS Rapid Response Team, GSFC. Caption by Adam Voiland.

    Instrument(s): Aqua - MODIS
  7. New York City

    This false-color satellite image shows greater New York City. The Island of Manhattan is jutting southward from top center, bordered by the Hudson River to the west and the East River to the east. (North is straight up in this scene.) In the middle of Manhattan, Central Park appears as a long green rectangle running roughly north-south with a large lake in the middle. Also visible are parts of Staten Island (bottom left corner) and Long Island (lower right).

    The area shown is as rich in history as it is in cultural diversity today. Human development in lower Manhattan began as early as 1100 A.D. Native American women farmed the land, growing mainly maize, beans, and squash. The first European explorers, led by Henry Hudson, arrived in New York Harbor in 1609 aboard the Halve Maen.The expedition was commissioned by the Dutch West India Company, which 17 years later bought the island from the Canarsie Indians for the equivalent of $23.70. The Dutch named their new land New Amsterdam and, with its population of 270 residents, the settlement had a fort, houses and farms.

    In 1653, the governor had a 9-foot-tall barricade built to keep out potential invaders from the north. The wall failed in its purpose, however, when in 1664 the English attacked the town by sea. (The street upon which this wall was built remains today as the famous Wall Street.)

    New York served as the United States’s first capital after the young nation won its independence from the British. George Washington, the first U.S. president, was sworn in at Federal Hall in 1789. Three years later, the first New York Stock Market was organized when twenty-two stockbrokers signed the “Buttonwood Agreement” under a buttonwood tree on Wall Street. The New York Stock and Exchange Board was founded in 1817, and relocated in 1903 to its current location on Broad Street. (Visit Lower Manhattan.info for more details about the city’s developmental timeline.)

    This false-color image was acquired on Sept. 8, 2002, by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA’s Terra satellite. The scene spans an area that is 27 km wide by 37 km tall. Vegetated land surface is green, paved urban areas are a whitish blue, and water is dark blue.

    Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

    Instrument(s): Terra - ASTER
  8. Thunderstorms over Borneo

    Crews aboard the International Space Station (ISS) have recently focused their cameras on panoramic views of clouds. Many of the photographs have been taken with lenses similar to the focal length of the human eye. Such images help us see Earth the way ISS crews see it from their perch 350 kilometers above—with a strong three-dimensional sense and a broad view of the planet.

    In this image, late afternoon sunlight casts long shadows from thunderhead anvils down onto southern Borneo. Near the horizon (image top center), more than 1000 kilometers away from the space station, storm formation is assisted by air currents rising over the central mountains of Borneo.

    Winds usually blow in different directions at different altitudes. At the time of this photo, high-altitude winds were clearly sweeping the tops off the many tallest thunderclouds, generating long anvils of diffuse cirrus plumes that trail south. At lower levels of the atmosphere, “streets” of white dots—fair-weather cumulus clouds—are aligned with west-moving winds. Small smoke plumes from forest fires in Borneo are also aligned west.

    Astronaut photograph ISS040-E-88891 was acquired on August 5, 2014, with a Nikon D3S digital camera using a 28 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by the Expedition 40 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Programsupports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Jacobs and Michael Trenchard, Barrios Technology at NASA-JSC.

    Instrument(s): ISS - Digital Camera
  9. Acid Lake in Java

    The turquoise lake in the crater of the Kawah Ijen volcano looks serene and inviting. It also happens to be the world’s largest acidic lake.

    The water in the crater lake has a pH less than 0.3 on a scale of 0 to 14 (7 is neutral). For comparison, lemon juice has a pH of 2; battery acid has a pH of 1. That acidity affects the chemistry of nearby river ecosystems, including the river Banyupahit.

    Originating at the lake, the Banyupahit delivers acidic water to populated areas downstream. According to a 2005 research paper, the river water that local farmers use to irrigate crops has a pH between 2.5 and 3.5. The normal range for stream water, according to the U.S. Geological Survey, is between about 6 and 8.

    On August 22, 2013, the Operational Land Imager (OLI) on Landsat 8 captured this view of the lake in East Java, Indonesia. The turquoise color comes from the range of materials dissolved in the water, including hydrochloric and sulfuric acids. The craters of several other volcanoes are also visible within the 20-kilometer-wide (12-mile) Ijen caldera.

    The plume drifting west from the crater likely comes from fumaroles, which release hot gases from underground magma. The plume could also come from hot springs and mud pots, according to Erik Klemetti, a volcanologist at Denison University. “The plume is white, so it is likely mostly steam with some other volcanic gases like carbon dioxide and sulfur dioxide mixed in.”

    Despite the presence of toxic gases around Kawah Ijen, workers mine sulfur by using a series of pipes installed under one of the volcano’s active vents. Gas inside the pipes condenses into molten sulfur as it moves toward the surface, where it then cools and hardens.

    NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey. Caption by Kathryn Hansen, with image interpretation from Erik Klemetti, Denison University.

    Instrument(s): Landsat 8 - OLI
  10. canadian-space-agency:

    NASA Astronaut Reid Wiseman aboard the ISS : “Good morning from space.” 

    Credit: Reid Wiseman/NASA

    (Source: twitter.com)

  11. Tarut Bay, Saudi Arabia

    Tarut Bay (also spelled Tarout or Tarot) is located along the coastline of the Arabian Gulf (also known as the Persian Gulf). The bay surrounds one of the largest islands in the Arabian Gulf—Tarut—which has an area of approximately 70 square kilometers (27 square miles). Archeological evidence suggests that the island has been continuously inhabited for more than 5,000 years. Today, the island hosts both suburban development and fishing industries. It is linked to the mainland city of Qatif to the west by two causeways that cross a narrow channel of the bay. (Note that north is to the left in this image.)

    The Ras Tanura peninsula, which forms the northern boundary of Tarut Bay, is occupied by residential compounds and industrial facilities owned by Saudi Aramco, one of the largest and most valuable oil companies in the world. In addition to the facilities along the natural shorelines and islands of the bay, numerous drill rigs and docking facilities have been constructed to support the activities of the petroleum industry. One striking example is the King Abdulaziz Seaport complex, located to the south of Tarut Bay in the Arabian Gulf. The port complex is essentially a small, self-supporting city with housing for employees, medical and support services, and water treatment plants.

    Green to turquoise ribbon-like features in the waters of Tarut Bay are likely a combination of phytoplankton and sediments moved by nearshore currents. Green areas near the city of Qatif include both farms and numerous fruit trees—such as date palms—which hearken back to the region’s history as an oasis.

    Astronaut photograph ISS036-E-2458 was acquired on May 18, 2013, with a Nikon D3S digital camera using a 400 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 36 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/JETS at NASA-JSC.

    Instrument(s): ISS - Digital Camera
  12. San Francisco Bay

    Astronauts aboard the International Space Station (ISS) recently photographed the San Francisco Bay area. The gray urban footprint of San Francisco, Oakland, San Jose, and their surrounding suburbs contrast strongly with the green hillsides. Of particular note are the Pacific Ocean water patterns that are highlighted in the sun glint. Sets of internal waves traveling east impinge on the coastline south of San Francisco. At the same time, fresher bay water flows out from the bay beneath the Golden Gate Bridge, creating a large plume traveling westward. Tidal current channels suggest the tidal flow deep in the bay. Because the ISS orbits are not synchronous with the sun, astronauts view the Earth with variable solar illumination angles. This allows them to document phenomena such as the sun reflecting differentially off surface waters in a way that outlines complicated water structures.

    Image ISS004-E-10288, was taken using a digital camera from the International Space Station and was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

    Instrument(s): ISS - Digital Camera
  13. San Francisco Skyline

    San Francisco is one of the largest cities in the United States. Roughly three quarters of a million people live within the city proper, with about seven million within the broader metropolitan area. The city predates the gold rush of 1849, but as a port city on the way to the California gold fields, San Francisco saw explosive population growth after the first discoveries were announced. By 1869, it was connected to the Eastern cities by railroad, and at that time, it was one of the ten largest cities in the United States despite being a full thousand miles or more west of “the frontier.” It remains a premier city of the United States.

    It is also arguably one of the most beautiful cities in the United States, sitting right on the San Francisco Bay. The city’s climate is moderated by its closeness to the Pacific Ocean, and the relative warmth of the Pacific air that flows toward the city over the cold water currents near the coastline is responsible for the city’s famous fogs. The city is bounded on the east by the rocky and forested hills of the Coast Range Mountains.

    There was no such fog on August 28, 2004, when the IKONOS satellite took this unusual oblique-angle image of the city’s financial district. By aiming its sensors off nadir, IKONOS was able to capture a sense of the city’s tall skyscrapers: a unique perspective on a unique city.

    Among the many emblems of San Francisco evident in this image is the Transamerican Pyramid Building, built in the late 1960s as the headquarters of the Transamerica Corporation. Designed specifically to allow light and air to reach down to the streets in ways conventional box-shaped buildings did not, its unique style and appearance made it an icon of the city and an internationally recognized landmark.

    Also visible is the Chinatown District of the city, the largest such Chinatown outside Asia. Although Chinese immigrants predated the gold rush, their numbers swelled in that time, mostly due to immigrants who came to run businesses to support gold miners. Businesses like groceries and dry-goods stores often proved far more lucrative than gold mining itself.

    East of Chinatown is Union Square, so named by the city’s first mayor, John Geary, after demonstrations supporting Union troops were held on the square on the eve of the Civil War. South of Union Square is Market Street, one of the major streets of the city. Market Street divides the financial district from the SOMA (south of Market) district, which hosts the Moscone Convention Center, the Yerba Buena gardens, and numerous art galleries, nightclubs, and exhibition galleries.

    In the lower left corner of the image, SBC Park, home to baseball’s San Francisco Giants, is clearly visible. Its right field wall juts out onto McCovey Cove, giving this ballpark the unusual distinction of being the only park where kayakers can catch home runs hit out of the park. The Bay Bridge connects the city with Oakland, and beyond that, to Interstate 80, which runs from San Francisco to New York City through Salt Lake City, Chicago, and other large cities.

    Image provided courtesy of Space Imaging

  14. Botany Bay, New South Wales

    On April 29, 1770, Captain Cook’s ship, the Endeavour, sailed into a sheltered bay on Australia’s eastern coast, bringing the first Europeans known to have visited the continent. Botany Bay, pictured in the image above, earned its name from the diverse collection of new and unfamiliar botanical specimens described and collected by the expedition’s botanist, Sir Joseph Banks. While other portions of Australia were known to Europe by that time, the fertile lands on the east coast were not. Previously explored coastal areas were considered inhospitable. This remains essentially true even today: Australia’s population of 20 million mostly live in the cities on or near the east or southeast coast.

    Cook suggested Botany Bay as a possible future colony site, but the settlers arriving with the First Fleet in January of 1788 found the cove to the north more suitable. On January 26, 1788, the settlers established the city of Sydney. That date is now celebrated in Australia as “Australia Day” and considered the founding of the nation.

    Sydney has grown a great deal since its beginnings, and today the city’s suburbs stretch south from Sydney Cove (out of the scene to the north) and surround Botany Bay (pictured). Two major Sydney landmarks are on or next to the bay: Port Botany, a major terminal for container ships (located at about 3 o’clock), and Kingsford-Smith Airport, Sydney’s international airport (located at about 12 o’clock). This natural-colour image, acquired by the IKONOS satellite on February 7, 2000, shows details as small as 4 meters (13 feet) across.

    Aircraft on the runways are clearly visible in the high-resolution image. Most of the planes have a distinct white fuselage and red tail, the colouration of the national airline, QANTAS. The strong red tone of much of the land around the bay reflects the prevalence of terracotta tile roofing. Light yellow arcs along the water’s edge are sandy beaches.

    The airport gets its name from the Australian aviation pioneer Sir Charles Edward Kingsford-Smith. He is best known for being the first pilot to cross the Pacific Ocean, flying from Oakland, California, to Brisbane, Queensland, via Hawaii and Fiji. Until the advent of long-range commericial aircraft, planes continued to use his flight route to reach Australia from the United States, but arriving in Sydney rather than Brisbane.

    Image by Jesse Allen, based on data copyright Space Imaging

  15. Lake District, North West England

    As its name suggests, the Lake District of the North West region of England is home to numerous large lakes. Although this national park owes its current appearance to the activity of glaciers, the landscape actually has a rich history of complex geological processes dating back half a billion years.

    The Enhanced Thematic Mapper on NASA’s Landsat 7 satellite captured this natural-color image of the Lake District National Park on May 7, 2000. Earth-toned crags rise above lower-lying lands carpeted with green. Like scratch marks from giant claws, the long, twisted lakes generally radiate outward from the center of the park.

    About 500 million years ago, the oldest rocks in the area sat at the bottom of an ancient sea. Oxygen-poor mud and debris settled on the sea floor and hardened into rock that has persisted over hundreds of millions of years. It is now named the Skiddaw Group, and its rocks are exposed in the northern third of the park.

    About 450 million years ago, the collision of tectonic plates initiated a period of intense volcanic activity. The resulting rocks comprise what is now known as the Borrowdale Volcanic Group, which forms the base of the mountainous middle of the park. The rocks are conspicuous brown peaks rising above the vegetated surroundings.

    The southern third of the Lake District consists of slates, siltstones, and sandstones. Called the Windemere Group, these rocks formed at the bottom of the ocean about 420 million years ago.

    About 400 million years ago, a mountain-building event known as the Caledonian Orogeny thrust all the rocks out of the sea, and magma reshaped the rock layers into complex configurations. The mountain range may have rivaled the height of today’s Himalaya, but millions of years of erosion wore the rocks down to low-profile hills and by 350 million years ago, the land was once again at the bottom of an ancient ocean. A layer of sea life detritus coated the older rocks, and those fossil shells and corals persist in the Lake District today. During theCarboniferous Period, mud infiltrated the shallow sea. Some 280 million years ago, another mountain-building event, the Variscan Orogeny, again lifted the rocks.

    In the hundreds of millions of years since today’s Lake District rocks formed, they not only rose and fell vertically, they also traveled northward. The rocks of today’s national park sat well south of the Equator about 500 million years ago.

    In much more recent geologic time—2 million years ago—Pleistocene glaciers crept southward to cover most of mainland Britain. The glaciers advanced and retreated multiple times, carving deep valleys that later filled with melt water and rain. The volcanic rock holds the water in place rather than allowing it to seep out, sustaining the lakes that give the park its name.

    1. References

    2. Lake District National Park. Geology. Accessed December 14, 2010.

    NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using Landsat data provided by theUnited States Geological Survey. Caption by Michon Scott.

    Instrument(s): Landsat 7 - ETM+