Earthscience - Blog Posts

Frozen: Ice on Earth and Well Beyond

Icy Hearts: A heart-shaped calving front of a glacier in Greenland (left) and Pluto's frozen plains (right). Credits: NASA/Maria-Jose Viñas and NASA/APL/SwRI

From deep below the soil at Earth’s polar regions to Pluto’s frozen heart, ice exists all over the solar system...and beyond. From right here on our home planet to moons and planets millions of miles away, we’re exploring ice and watching how it changes. Here’s 10 things to know:

1. Earth’s Changing Ice Sheets

An Antarctic ice sheet. Credit: NASA

Ice sheets are massive expanses of ice that stay frozen from year to year and cover more than 6 million square miles. On Earth, ice sheets extend across most of Greenland and Antarctica. These two ice sheets contain more than 99 percent of the planet’s freshwater ice. However, our ice sheets are sensitive to the changing climate.

Data from our GRACE satellites show that the land ice sheets in both Antarctica and Greenland have been losing mass since at least 2002, and the speed at which they’re losing mass is accelerating.

2. Sea Ice at Earth’s Poles

Earth’s polar oceans are covered by stretches of ice that freezes and melts with the seasons and moves with the wind and ocean currents. During the autumn and winter, the sea ice grows until it reaches an annual maximum extent, and then melts back to an annual minimum at the end of summer. Sea ice plays a crucial role in regulating climate – it’s much more reflective than the dark ocean water, reflecting up to 70 percent of sunlight back into space; in contrast, the ocean reflects only about 7 percent of the sunlight that reaches it. Sea ice also acts like an insulating blanket on top of the polar oceans, keeping the polar wintertime oceans warm and the atmosphere cool.

Some Arctic sea ice has survived multiple years of summer melt, but our research indicates there’s less and less of this older ice each year. The maximum and minimum extents are shrinking, too. Summertime sea ice in the Arctic Ocean now routinely covers about 30-40 percent less area than it did in the late 1970s, when near-continuous satellite observations began. These changes in sea ice conditions enhance the rate of warming in the Arctic, already in progress as more sunlight is absorbed by the ocean and more heat is put into the atmosphere from the ocean, all of which may ultimately affect global weather patterns.

3. Snow Cover on Earth

Snow extends the cryosphere from the poles and into more temperate regions.

Snow and ice cover most of Earth’s polar regions throughout the year, but the coverage at lower latitudes depends on the season and elevation. High-elevation landscapes such as the Tibetan Plateau and the Andes and Rocky Mountains maintain some snow cover almost year-round. In the Northern Hemisphere, snow cover is more variable and extensive than in the Southern Hemisphere.

Snow cover the most reflective surface on Earth and works like sea ice to help cool our climate. As it melts with the seasons, it provides drinking water to communities around the planet.

4. Permafrost on Earth

Tundra polygons on Alaska's North Slope. As permafrost thaws, this area is likely to be a source of atmospheric carbon before 2100. Credit: NASA/JPL-Caltech/Charles Miller

Permafrost is soil that stays frozen solid for at least two years in a row. It occurs in the Arctic, Antarctic and high in the mountains, even in some tropical latitudes. The Arctic’s frozen layer of soil can extend more than 200 feet below the surface. It acts like cold storage for dead organic matter – plants and animals.

In parts of the Arctic, permafrost is thawing, which makes the ground wobbly and unstable and can also release those organic materials from their icy storage. As the permafrost thaws, tiny microbes in the soil wake back up and begin digesting these newly accessible organic materials, releasing carbon dioxide and methane, two greenhouse gases, into the atmosphere.

Two campaigns, CARVE and ABoVE, study Arctic permafrost and its potential effects on the climate as it thaws.

5. Glaciers on the Move

Did you know glaciers are constantly moving? The masses of ice act like slow-motion rivers, flowing under their own weight. Glaciers are formed by falling snow that accumulates over time and the slow, steady creep of flowing ice. About 10 percent of land area on Earth is covered with glacial ice, in Greenland, Antarctica and high in mountain ranges; glaciers store much of the world's freshwater.

Our satellites and airplanes have a bird’s eye view of these glaciers and have watched the ice thin and their flows accelerate, dumping more freshwater ice into the ocean, raising sea level.

6. Pluto’s Icy Heart

The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Pluto's surrounding uplands. NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto’s most famous feature – that heart! – is stone cold. First spotted by our New Horizons spacecraft in 2015, the heart’s western lobe, officially named Sputnik Planitia, is a deep basin containing three kinds of ices – frozen nitrogen, methane and carbon monoxide.

Models of Pluto’s temperatures show that, due the dwarf planet’s extreme tilt (119 degrees compared to Earth’s 23 degrees), over the course of its 248-year orbit, the latitudes near 30 degrees north and south are the coldest places – far colder than the poles. Ice would have naturally formed around these latitudes, including at the center of Sputnik Planitia.

New Horizons also saw strange ice formations resembling giant knife blades. This “bladed terrain” contains structures as tall as skyscrapers and made almost entirely of methane ice, likely formed as erosion wore away their surfaces, leaving dramatic crests and sharp divides. Similar structures can be found in high-altitude snowfields along Earth’s equator, though on a very different scale.

7. Polar Ice on Mars

This image, combining data from two instruments aboard our Mars Global Surveyor, depicts an orbital view of the north polar region of Mars. Credit: NASA/JPL-Caltech/MSSS

Mars has bright polar caps of ice easily visible from telescopes on Earth. A seasonal cover of carbon dioxide ice and snow advances and retreats over the poles during the Martian year, much like snow cover on Earth.

This animation shows a side-by-side comparison of CO2 ice at the north (left) and south (right) Martian poles over the course of a typical year (two Earth years). This simulation isn't based on photos; instead, the data used to create it came from two infrared instruments capable of studying the poles even when they're in complete darkness. This data were collected by our Mars Reconnaissance Orbiter, and Mars Global Surveyor. Credit: NASA/JPL-Caltech

During summertime in the planet's north, the remaining northern polar cap is all water ice; the southern cap is water ice as well, but remains covered by a relatively thin layer of carbon dioxide ice even in summertime.

Scientists using radar data from our Mars Reconnaissance Orbiter found a record of the most recent Martian ice age in the planet's north polar ice cap. Research indicates a glacial period ended there about 400,000 years ago. Understanding seasonal ice behavior on Mars helps scientists refine models of the Red Planet's past and future climate.

8. Ice Feeds a Ring of Saturn

Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturn's moon Enceladus into the E ring, while the moon's active south polar jets continue to fire away. Credit: NASA/JPL/Space Science Institute

Saturn’s rings and many of its moons are composed of mostly water ice – and one of its moons is actually creating a ring. Enceladus, an icy Saturnian moon, is covered in “tiger stripes.” These long cracks at Enceladus’ South Pole are venting its liquid ocean into space and creating a cloud of fine ice particles over the moon's South Pole. Those particles, in turn, form Saturn’s E ring, which spans from about 75,000 miles (120,000 kilometers) to about 260,000 miles (420,000 kilometers) above Saturn's equator. Our Cassini spacecraft discovered this venting process and took high-resolution images of the system.

Jets of icy particles burst from Saturn’s moon Enceladus in this brief movie sequence of four images taken on Nov. 27, 2005. Credit: NASA/JPL/Space Science Institute

9. Ice Rafts on Europa

View of a small region of the thin, disrupted, ice crust in the Conamara region of Jupiter's moon Europa showing the interplay of surface color with ice structures. Credit: NASA/JPL/University of Arizona

The icy surface of Jupiter’s moon Europa is crisscrossed by long fractures. During its flybys of Europa, our Galileo spacecraft observed icy domes and ridges, as well as disrupted terrain including crustal plates that are thought to have broken apart and "rafted" into new positions. An ocean with an estimated depth of 40 to 100 miles (60 to 150 kilometers) is believed to lie below that 10- to 15-mile-thick (15 to 25 km) shell of ice.

The rafts, strange pits and domes suggest that Europa’s surface ice could be slowly turning over due to heat from below. Our Europa Clipper mission, targeted to launch in 2022, will conduct detailed reconnaissance of Europa to see whether the icy moon could harbor conditions suitable for life.

10. Crater Ice on Our Moon

The image shows the distribution of surface ice at the Moon’s south pole (left) and north pole (right), detected by our Moon Mineralogy Mapper instrument. Credit: NASA

In the darkest and coldest parts of our Moon, scientists directly observed definitive evidence of water ice. These ice deposits are patchy and could be ancient. Most of the water ice lies inside the shadows of craters near the poles, where the warmest temperatures never reach above -250 degrees Fahrenheit. Because of the very small tilt of the Moon’s rotation axis, sunlight never reaches these regions.

A team of scientists used data from a our instrument on India’s Chandrayaan-1 spacecraft to identify specific signatures that definitively prove the water ice. The Moon Mineralogy Mapper not only picked up the reflective properties we’d expect from ice, but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice.

With enough ice sitting at the surface – within the top few millimeters – water would possibly be accessible as a resource for future expeditions to explore and even stay on the Moon, and potentially easier to access than the water detected beneath the Moon’s surface.

11. Bonus: Icy World Beyond Our Solar System!

With an estimated temperature of just 50K, OGLE-2005-BLG-390L b is the chilliest exoplanet yet discovered. Pictured here is an artist's concept. Credit: NASA

OGLE-2005-BLG-390Lb, the icy exoplanet otherwise known as Hoth, orbits a star more than 20,000 light years away and close to the center of our Milky Way galaxy. It’s locked in the deepest of deep freezes, with a surface temperature estimated at minus 364 degrees Fahrenheit (minus 220 Celsius)!

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The Darkness that Followed Hurricane Michael

Earlier this month, the southeastern United States was struck by Hurricane Michael. After the category 4 storm made landfall on Oct. 10, 2018, Hurricane Michael proceeded to knock out power for at least 2.5 million customers across Florida, Georgia, North Carolina, and Virginia. 

In this data visualization, you can clearly see where the lights were taken out in Panama City, Florida. A team of our scientists from Goddard Space Flight Center processed and corrected the raw data to filter out stray light from the Moon, fires, airglow, and any other sources that are not electric lights. They also removed atmosphere interference from dust, haze, and clouds. 

In the visualization above, you can see a natural view of the night lights—and a step of the filtering process in an effort to clean up some of the cloud cover. The line through the middle is the path Hurricane Michael took. 

Although the damage was severe, tens of thousands of electric power industry workers from all over the country—and even Canada—worked together to restore power to the affected areas. Most of the power was restored by Oct. 15, but some people still need to wait a little longer for the power grids to be rebuilt. Read more here. 

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World Teacher Appreciation Day!

On #WorldTeachersDay, we are recognizing our two current astronauts who are former classroom teachers, Joe Acaba and Ricky Arnold, as well as honoring teachers everywhere. What better way to celebrate than by learning from teachers who are literally out-of-this-world!

During the past Year of Education on Station, astronauts connected with more than 175,000 students and 40,000 teachers during live Q & A sessions. 

Let’s take a look at some of the questions those students asked:

The view from space is supposed to be amazing. Is it really that great and could you explain? 

Taking a look at our home planet from the International Space Station is one of the most fascinating things to see! The views and vistas are unforgettable, and you want to take everyone you know to the Cupola (window) to experience this. Want to see what the view is like? Check out earthkam to learn more.

What kind of experiments do you do in space?

There are several experiments that take place on a continuous basis aboard the orbiting laboratory - anything from combustion to life sciences to horticulture. Several organizations around the world have had the opportunity to test their experiments 250 miles off the surface of the Earth. 

What is the most overlooked attribute of an astronaut?

If you are a good listener and follower, you can be successful on the space station. As you work with your team, you can rely on each other’s strengths to achieve a common goal. Each astronaut needs to have expeditionary skills to be successful. Check out some of those skills here. 

Are you able to grow any plants on the International Space Station?

Nothing excites Serena Auñón-Chancellor more than seeing a living, green plant on the International Space Station. She can’t wait to use some of the lettuce harvest to top her next burger! Learn more about the plants that Serena sees on station here. 

What food are you growing on the ISS and which tastes the best? 

While aboard the International Space Station, taste buds may not react the same way as they do on earth but the astronauts have access to a variety of snacks and meals. They have also grown 12 variants of lettuce that they have had the opportunity to taste.

Learn more about Joe Acaba, Ricky Arnold, and the Year of Education on Station.

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Did somebody say space laser?

We’re set to launch ICESat-2, our most advanced laser instrument of its kind, into orbit around Earth on Sept. 15. The Ice, Cloud and land Elevation Satellite-2 will make critical observations of how ice sheets, glaciers and sea ice are changing over time, helping us better understand how those changes affect people where they live. Here’s 10 numbers to know about this mission:

One Space Laser

There’s only one scientific instrument on ICESat-2, but it’s a marvel. The Advanced Topographic Laser Altimeter System, or ATLAS, measures height by precisely timing how long it takes individual photons of light from a laser to leave the satellite, bounce off Earth, and return to ICESat-2. Hundreds of people at our Goddard Space Flight Center worked to build this smart-car-sized instrument to exacting requirements so that scientists can measure minute changes in our planet’s ice.

Sea ice is seen in front of Apusiaajik Glacier in Greenland. Credit: NASA/JPL-Caltech/Jim Round

Two Types of Ice

Not all ice is the same. Land ice, like the ice sheets in Greenland and Antarctica, or glaciers dotting the Himalayas, builds up as snow falls over centuries and forms compacted layers. When it melts, it can flow into the ocean and raise sea level. Sea ice, on the other hand, forms when ocean water freezes. It can last for years, or a single winter. When sea ice disappears, there is no effect on sea level (think of a melting ice cube in your drink), but it can change climate and weather patterns far beyond the poles.

3-Dimensional Earth

ICESat-2 will measure elevation to see how much glaciers, sea ice and ice sheets are rising or falling. Our fleet of satellites collect detailed images of our planet that show changes to features like ice sheets and forests, and with ICESat-2’s data, scientists can add the third dimension – height – to those portraits of Earth.

Four Seasons, Four Measurements

ICESat-2’s orbit will make 1,387 unique ground tracks around Earth in 91 days – and then start the same ground pattern again at the beginning. This allows the satellite to measure the same ground tracks four times a year and scientists to see how glaciers and other frozen features change with the seasons – including over winter.

532 Nanometer Wavelength

The ATLAS instrument will measure ice with a laser that shines at 532 nanometers – a bright green on the visible spectrum. When these laser photons return to the satellite, they pass through a series of filters that block any light that’s not exactly at this wavelength. This helps the instrument from being swamped with all the other shades of sunlight naturally reflected from Earth.

Six Laser Beams

While the first ICESat satellite (2003-2009) measured ice with a single laser beam, ICESat-2 splits its laser light into six beams – the better to cover more ground (or ice). The arrangement of the beams into three pairs will also allow scientists to assess the slope of the surface they’re measuring.

Seven Kilometers Per Second

ICESat-2 will zoom above the planet at 7 km per second (4.3 miles per second), completing an orbit around Earth in 90 minutes. The orbits have been set to converge at the 88-degree latitude lines around the poles, to focus the data coverage in the region where scientists expect to see the most change.

800-Picosecond Precision

All of those height measurements come from timing the individual laser photons on their 600-mile roundtrip between the satellite and Earth’s surface – a journey that is timed to within 800 picoseconds. That’s a precision of nearly a billionth of a second. Our engineers had to custom build a stopwatch-like device, because no existing timers fit the strict requirements.

Nine Years of Operation IceBridge

As ICESat-2 measures the poles, it adds to our record of ice heights that started with the first ICESat and continued with Operation IceBridge, an airborne mission that has been flying over the Arctic and Antarctic for nine years. The campaign, which bridges the gap between the two satellite missions, has flown since 2009, taking height measurements and documenting the changing ice.

10,000 Pulses a Second

ICESat-2’s laser will fire 10,000 times in one second. The original ICESat fired 40 times a second. More pulses mean more height data. If ICESat-2 flew over a football field, it would take 130 measurements between end zones; its predecessor, on the other hand, would have taken one measurement in each end zone.

And One Bonus Number: 300 Trillion

Each laser pulse ICESat-2 fires contains about 300 trillion photons! Again, the laser instrument is so precise that it can time how long it takes individual photons to return to the satellite to within one billionth of a second. 

Learn more about ICESat-2: https://www.nasa.gov/icesat-2

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Capturing Space Stories, One Click at a Time!

It’s World Photography Day!

To celebrate the occasion, we’re sharing photos from our photographers that chronicle what's making news across the agency - from launches and landings to important science announcements to images taken from the vantage point of space.

Take a look!

A Closer View of the Moon 

Posted to Twitter by European Space Agency astronaut Alexander Gerst, this image shows our planet's Moon as seen from the International Space Station. As he said in the tweet, "By orbiting the Earth almost 16 times per day, the #ISS crew travel the distance to the Moon and back – every day. #Horizons"

The International Space Station is the world's only orbital laboratory. An international partnership of space agencies provides and operates the elements of the station. The principals are the space agencies of the United States, Russia, Europe, Japan and Canada.

Photo Credit: NASA

Spacewalk Selfie

NASA astronaut Ricky Arnold took this selfie during the May 16, 2018, spacewalk to perform upgrades on the International Space Station, saying in a tweet "An amazing view of our one and only planet."

Arnold and fellow spacewalker Drew Feustel donned spacesuits and worked for more than six hours outside the station to finish upgrading cooling system hardware and install new and updated communications equipment for future dockings of commercial crew spacecraft.

Photo Credit: NASA

Preparing to Leave Earth

The mobile service tower at Space Launch Complex-3 is rolled back to reveal the United Launch Alliance Atlas-V rocket with NASA’s InSight spacecraft onboard, Friday, May 4, 2018, at Vandenberg Air Force Base in California. InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is a Mars lander designed to study the "inner space" of Mars: its crust, mantle, and core. 

Photo Credit: NASA/Bill Ingalls

Launch Long Exposure

The United Launch Alliance Delta IV Heavy rocket is seen in this long exposure photograph as it launches NASA's Parker Solar Probe to touch the Sun, Sunday, Aug. 12, 2018 from Launch Complex 37 at Cape Canaveral Air Force Station, Florida. Parker Solar Probe is humanity’s first-ever mission into a part of the Sun’s atmosphere called the corona.  Here it will directly explore solar processes that are key to understanding and forecasting space weather events that can impact life on Earth.

Photo Credit: NASA/Bill Ingalls

Waving Farewell

Expedition 56 flight engineer Serena Auñón-Chancellor of NASA waves farewell to family and friends as she and Soyuz Commander Sergey Prokopyev of Roscosmos and flight engineer Alexander Gerst of European Space Agency depart Building 254 for the launch pad a few hours before their launch, Wednesday, June 6, 2018 at the Baikonur Cosmodrome in Kazakhstan. Auñón-Chancellor, Prokopyev, and Gerst launched aboard the Soyuz MS-09 spacecraft at 7:12am EDT (5:12pm Baikonur time) on June 6 to begin their journey to the International Space Station.

Photo Credit: NASA/Victor Zelentsov

Launching Humans to Space

The Soyuz MS-09 rocket is launched with Expedition 56 Soyuz Commander Sergey Prokopyev of Roscosmos, flight engineer Serena Auñón-Chancellor of NASA, and flight engineer Alexander Gerst of ESA (European Space Agency), Wednesday, June 6, 2018 at the Baikonur Cosmodrome in Kazakhstan. Prokopyev, Auñón-Chancellor, and Gerst will spend the next six months living and working aboard the International Space Station. 

Photo Credit: NASA/Joel Kowsky

Rethinking Aircraft Design

In an effort to improve fuel efficiency, NASA and the aircraft industry are rethinking aircraft design. Inside the 8’ x 6’ wind tunnel at NASA Glenn Research Center, engineers tested a fan and inlet design, commonly called a propulsor, which could use four to eight percent less fuel than today’s advanced aircraft.

Photo Credit: NASA/Rami Daud

Flying Observatory

SOFIA, the Stratospheric Observatory for Infrared Astronomy, is the largest airborne observatory in the world, capable of making observations that are impossible for even the largest and highest ground-based telescopes. During its lifetime, SOFIA also will inspire the development of new scientific instrumentation and foster the education of young scientists and engineers.

Photo Credit: NASA/SOFIA/Waynne Williams

Experimenting with Venus-like conditions

A close-up view of crystals that developed on materials exposed to conditions on Venus in NASA Glenn’s Extreme Environments Rig. This unique and world class ground-based test rig can accurately most simulate atmospheric conditions for any planet or moon in the solar system and beyond.

Photo Credit: NASA/Bridget Caswell

Honeycomb Close Up

A close-up view of 3-D printed honeycomb patterns made in NASA Glenn manufacturing lab using a method called binder jetting. The honeycomb structures can find use in several applications such as a strong core for lightweight sandwich panels, acoustic panels for noise attenuation and innovative cellular structures.

Photo Credit: NASA/Marvin Smith

To see even more photos of our space exploration efforts, visit us on Flickr: https://www.flickr.com/photos/nasahqphoto/.

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9 Ocean Facts You Likely Don’t Know, but Should

Earth is a place dominated by water, mainly oceans. It’s also a place our researchers study to understand life. Trillions of gallons of water flow freely across the surface of our blue-green planet. Ocean’s vibrant ecosystems impact our lives in many ways. 

In celebration of World Oceans Day, here are a few things you might not know about these complex waterways.

1. Why is the ocean blue? 

The way light is absorbed and scattered throughout the ocean determines which colors it takes on. Red, orange, yellow,and green light are absorbed quickly beneath the surface, leaving blue light to be scattered and reflected back. This causes us to see various blue and violet hues.

2. Want a good fishing spot? 

Follow the phytoplankton! These small plant-like organisms are the beginning of the food web for most of the ocean. As phytoplankton grow and multiply, they are eaten by zooplankton, small fish and other animals. Larger animals then eat the smaller ones. The fishing industry identifies good spots by using ocean color images to locate areas rich in phytoplankton. Phytoplankton, as revealed by ocean color, frequently show scientists where ocean currents provide nutrients for plant growth.

3. The ocean is many colors. 

When we look at the ocean from space, we see many different shades of blue. Using instruments that are more sensitive than the human eye, we can measure carefully the fantastic array of colors of the ocean. Different colors may reveal the presence and amount of phytoplankton, sediments and dissolved organic matter.

4. The ocean can be a dark place. 

About 70 percent of the planet is ocean, with an average depth of more than 12,400 feet. Given that light doesn’t penetrate much deeper than 330 feet below the water’s surface (in the clearest water), most of our planet is in a perpetual state of darkness. Although dark, this part of the ocean still supports many forms of life, some of which are fed by sinking phytoplankton. 

5. We study all aspects of ocean life. 

Instruments on satellites in space, hundreds of kilometers above us, can measure many things about the sea: surface winds, sea surface temperature, water color, wave height, and height of the ocean surface.

6. In a gallon of average sea water, there is about 1/2 cup of salt. 

The amount of salt varies depending on location. The Atlantic Ocean is saltier than the Pacific Ocean, for instance. Most of the salt in the ocean is the same kind of salt we put on our food: sodium chloride.

7. A single drop of sea water is teeming with life.  

It will most likely have millions (yes, millions!) of bacteria and viruses, thousands of phytoplankton cells, and even some fish eggs, baby crabs, and small worms. 

8. Where does Earth store freshwater? 

Just 3.5 percent of Earth’s water is fresh—that is, with few salts in it. You can find Earth’s freshwater in our lakes, rivers, and streams, but don’t forget groundwater and glaciers. Over 68 percent of Earth’s freshwater is locked up in ice and glaciers. And another 30 percent is in groundwater. 

9. Phytoplankton are the “lungs of the ocean”.

Just like forests are considered the “lungs of the earth”, phytoplankton is known for providing the same service in the ocean! They consume carbon dioxide, dissolved in the sunlit portion of the ocean, and produce about half of the world’s oxygen. 

Want to learn more about how we study the ocean? Follow @NASAEarth on twitter.

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See Why Our Researchers Explore Earth's Extreme and Remote Environments

When we talk about exploration in far-flung places, you might think of space telescopes taking images of planets outside our solar system, or astronauts floating on the International Space Station. 

But did you know our researchers travel to some of Earth's most inaccessible and dangerous places, too? 

Two scientists working with the ICESat-2 mission just finished a trek from the South Pole to latitude 88 south, a journey of about 450 miles. They had to travel during the Antarctic summer - the region's warmest time, with near-constant sunshine - but the trek was still over solid ice and snow. 

The trip lasted 14 days, and was an important part of a process known as calibration and validation. ICESat-2 will launch this fall, and the team was taking extremely precise elevation measurements that will be used to validate those taken by the satellite. 

Sometimes our research in Earth's remote regions helps us understand even farther-flung locations…like other planets. 

Geologic features on Mars look very similar to islands and landforms created by volcanoes here on our home planet. 

As hot jets of magma make their way to Earth's surface, they create new rocks and land - a process that may have taken place on Mars and the Moon.

In 2015, our researchers walked on newly cooled lava on the Holuhraun volcano in Iceland to take measurements of the landscape, in order to understand similar processes on other rocky bodies in our solar system.

There may not be flowing lava in the mangrove forests in Gabon, but our researchers have to brave mosquitoes and tree roots that reach up to 15-foot high as they study carbon storage in the vegetation there.

The scientists take some measurements from airplanes, but they also have to gather data from the ground in one our of planet's most pristine rainforests, climbing over and around roots that can grow taller than people. They use these measurements to create a 3-D map of the ecosystem, which helps them understand how much carbon in stored in the plants. 

You can follow our treks to Earth’s most extreme locales on our Earth Expeditions blog.

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Solar System: 10 Things to Know This Week

The Living Planet Edition

Whether it's crops, forests or phytoplankton blooms in the ocean, our scientists are tracking life on Earth. Just as satellites help researchers study the atmosphere, rainfall and other physical characteristics of the planet, the ever-improving view from above allows them to study Earth's interconnected life.

1. Life on Earth, From Space

While we (NASA) began monitoring life on land in the 1970s with the Landsat satellites, this fall marks 20 years since we've continuously observed all the plant life at the surface of both the land and ocean. The above animation captures the entirety of two decades of observations.

2. Watching the World Breathe

With the right tools, we can see Earth breathe. With early weather satellite data in the 1970s and '80s, NASA Goddard scientist Compton Tucker was able to see plants' greening and die-back from space. He developed a way of comparing satellite data in two wavelengths.

When healthy plants are stocked with chlorophyll and ready to photosynthesize to make food (and absorb carbon dioxide), leaves absorb red light but reflect infrared light back into space. By comparing the ratio of red to infrared light, Tucker and his colleagues could quantify vegetation covering the land.

Expanding the study to the rest of the globe, the scientists could track rainy and dry seasons in Africa, see the springtime blooms in North America, and wildfires scorching forests worldwide.

3. Like Breathing? Thank Earth's Ocean

But land is only part of the story. The ocean is home to 95 percent of Earth's living space, covering 70 percent of the planet and stretching miles deep. At the base of the ocean's food web is phytoplankton - tiny plants that also undergo photosynthesis to turn nutrients and carbon dioxide into sugar and oxygen. Phytoplankton not only feed the rest of ocean life, they absorb carbon dioxide - and produce about half the oxygen we breathe.

In the Arctic Ocean, an explosion of phytoplankton indicates change. As seasonal sea ice melts, warming waters and more sunlight will trigger a sudden, massive phytoplankton bloom that feeds birds, sea lions and newly-hatched fish. But with warming atmospheric temperatures, that bloom is now happening several weeks earlier - before the animals are in place to take advantage of it.

4. Keeping an Eye on Crops

The "greenness" measurement that scientists use to measure forests and grasslands can also be used to monitor the health of agricultural fields. By the 1980s, food security analysts were approaching NASA to see how satellite images could help with the Famine Early Warning System to identify regions at risk - a partnership that continues today.

With rainfall estimates, vegetation measurements, as well as the recent addition of soil moisture information, our scientists can help organizations like USAID direct emergency help.

The view from space can also help improve agricultural practices. A winery in California, for example, uses individual pixels of Landsat data to determine when to irrigate and how much water to use.

5. Coming Soon to the International Space Station

A laser-based instrument being developed for the International Space Station will provide a unique 3-D view of Earth's forests. The instrument, called GEDI, will be the first to systematically probe the depths of the forests from space.

Another ISS instrument in development, ECOSTRESS, will study how effectively plants use water. That knowledge provided on a global scale from space will tell us "which plants are going to live or die in a future world of greater droughts," said Josh Fisher, a research scientist at NASA's Jet Propulsion Laboratory and science lead for ECOSTRESS.

6. Seeing Life, From the Microscopic to Multicellular

Scientists have used our vantage from space to study changes in animal habitats, track disease outbreaks, monitor forests and even help discover a new species. Bacteria, plants, land animals, sea creatures and birds reveal a changing world.

Our Black Marble image provides a unique view of human activity. Looking at trends in our lights at night, scientists can study how cities develop over time, how lighting and activity changes during certain seasons and holidays, and even aid emergency responders during power outages caused by natural disasters.

7. Earth as Analog and Proving Ground

Just as our Mars rovers were tested in Earth's deserts, the search for life on ocean moons in our solar system is being refined by experiments here. JPL research scientist Morgan Cable looks for life on the moons of Jupiter and Saturn. She cites satellite observations of Arctic and Antarctic ice fields that are informing the planning for a future mission to Europa, an icy moon of Jupiter.

The Earth observations help researchers find ways to date the origin of jumbled, chaotic ice. "When we visit Europa, we want to go to very young places, where material from that ocean is being expressed on the surface," she explained. "Anywhere like that, the chances of finding biomarkers goes up - if they're there."

8. Only One Living Planet

Today, we know of only one living planet: our own. The knowledge and tools NASA developed to study life here are among our greatest assets as we begin the search for life beyond Earth.

There are two main questions: With so many places to look, how can we home in on the places most likely to harbor life? What are the unmistakable signs of life - even if it comes in a form we don't fully understand? In this early phase of the search, "We have to go with the only kind of life we know," said Tony del Genio, co-lead of a new NASA interdisciplinary initiative to search for life on other worlds.

So, the focus is on liquid water. Even bacteria around deep-sea vents that don't need sunlight to live need water. That one necessity rules out many planets that are too close or too far from their stars for water to exist, or too far from us to tell. Our Galileo and Cassini missions revealed that some moons of Jupiter and Saturn are not the dead rocks astronomers had assumed, but appear to have some conditions needed for life beneath icy surfaces.

9. Looking for Life Beyond Our Solar System

In the exoplanet (planets outside our solar system that orbit another star) world, it's possible to calculate the range of distances for any star where orbiting planets could have liquid water. This is called the star's habitable zone. Astronomers have already located some habitable-zone planets, and research scientist Andrew Rushby of NASA Ames Research Center is researching ways to refine the search. "An alien would spot three planets in our solar system in the habitable zone [Earth, Mars and Venus]," Rushby said, "but we know that 67 percent of those planets are not inhabited."

He recently developed a model of Earth's carbon cycle and combined it with other tools to study which planets in habitable zones would be the best targets to look for life, considering probable tectonic activity and water cycles. He found that larger planets are more likely than smaller ones to have surface temperatures conducive to liquid water. Other exoplanet researchers are looking for rocky worlds, and biosignatures, the chemical signs of life.

10. You Can Learn a Lot from a Dot

When humans start collecting direct images of exoplanets, even the closest ones will appear as only a handful of pixels in the detector - something like the famous "blue dot" image of Earth from Saturn. What can we learn about life on these planets from a single dot?

Stephen Kane of the University of California, Riverside, has come up with a way to answer that question by using our EPIC camera on NOAA's DSCOVR satellite. "I'm taking these glorious pictures and collapsing them down to a single pixel or handful of pixels," Kane explained. He runs the light through a noise filter that attempts to simulate the interference expected from an exoplanet mission. By observing how the brightness of Earth changes when mostly land is in view compared with mostly water, Kane reverse-engineers Earth's rotation rate - something that has yet to be measured directly for exoplanets.

The most universal, most profound question about any unknown world is whether it harbors life. The quest to find life beyond Earth is just beginning, but it will be informed by the study of our own living planet.

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Observing the Ozone Hole from Space: A Science Success Story

Using our unique ability to view Earth from space, we are working together with NOAA to monitor an emerging success story – the shrinking ozone hole over Antarctica.

Thirty years ago, the nations of the world agreed to the landmark ‘Montreal Protocol on Substances that Deplete the Ozone Layer.’ The Protocol limited the release of ozone-depleting chlorofluorocarbons (CFCs) into the atmosphere.

Since the 1960s our scientists have worked with NOAA researchers to study the ozone layer. 

We use a combination of satellite, aircraft and balloon measurements of the atmosphere.

The ozone layer acts like a sunscreen for Earth, blocking harmful ultraviolet, or UV, rays emitted by the Sun.

In 1985, scientists first reported a hole forming in the ozone layer over Antarctica. It formed over Antarctica because the Earth’s atmospheric circulation traps air over Antarctica.  This air contains chlorine released from the CFCs and thus it rapidly depletes the ozone.

Because colder temperatures speed up the process of CFCs breaking up and releasing chlorine more quickly, the ozone hole fluctuates with temperature. The hole shrinks during the warmer summer months and grows larger during the southern winter. In September 2006, the ozone hole reached a record large extent.

But things have been improving in the 30 years since the Montreal Protocol. Thanks to the agreement, the concentration of CFCs in the atmosphere has been decreasing, and the ozone hole maximum has been smaller since 2006’s record.

That being said, the ozone hole still exists and fluctuates depending on temperature because CFCs have very long lifetimes. So, they still exist in our atmosphere and continue to deplete the ozone layer.

To get a view of what the ozone hole would have looked like if the world had not come to the agreement to limit CFCs, our scientists developed computer models. These show that by 2065, much of Earth would have had almost no ozone layer at all.

Luckily, the Montreal Protocol exists, and we’ve managed to save our protective ozone layer. Looking into the future, our scientists project that by 2065, the ozone hole will have returned to the same size it was thirty years ago.

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