This week, we’re at one of the biggest science conferences in the country, where our scientists are presenting new results from our missions and projects. It’s called the American Geophysical Union’s Fall Meeting.
Here are a few of the things we shared this week…
A few months into its seven-year mission, Parker Solar Probe has already flown far closer to the Sun than any spacecraft has ever gone. The data from this visit to the Sun has just started to come back to Earth, and scientists are hard at work on their analysis.
Parker Solar Probe sent us this new view of the Sun’s outer atmosphere, the corona. The image was taken by the mission’s WISPR instrument on Nov. 8, 2018, and shows a coronal streamer seen over the east limb of the Sun. Coronal streamers are structures of solar material within the Sun’s atmosphere, the corona, that usually overlie regions of increased solar activity. The fine structure of the streamer is very clear, with at least two rays visible. Parker Solar Probe was about 16.9 million miles from the Sun’s surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction.
Using a satellite view of human lights, our scientists watched the lights go out in Puerto Rico after Hurricane Maria. They could see the slow return of electricity to the island, and track how rural and mountainous regions took longer to regain power.
In the spring, a team of scientists flew a plane over Puerto Rico’s forests, using a laser instrument to measure how trees were damaged and how the overall structure of the forests had changed.
Our scientists who study Antarctica saw some surprising changes to East Antarctica. Until now, most of the continent’s melting has been on the peninsula and West Antarctica, but our scientists have seen glaciers in East Antarctica lose lots of ice in the last few years.
Our ICESat-2 team showed some of their brand new data. From the changing height of Antarctic ice to lagoons off the coast of Mexico, the little satellite has spent its first few months measuring our planet in 3D. The laser pulses even see individual ocean waves, in this graph.
Scientists are using our satellite data to track Adélie penguin populations, by using an unusual proxy – pictures of their poop! Penguins are too small to be seen by satellites, but they can see large amounts of their poop (which is pink!) and use that as a proxy for penguin populations.
Our OSIRIS-REx mission recently arrived at its destination, asteroid Bennu. On approach, data from the spacecraft’s spectrometers revealed chemical signatures of water trapped in clay minerals. While Bennu itself is too small to have ever hosted liquid water, the finding indicates that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.
We also released a new, detailed shape model of Bennu, which is very similar to our ground-based observations of Bennu’s shape. This is a boon to ground-based radar astronomy since this is our first validation of the accuracy of the method for an asteroid! One change from the original shape model is the size of the large boulder near Bennu’s south pole, nicknamed “Benben.” The boulder is much bigger than we thought and overall, the quantity of boulders on the surface is higher than expected. Now the team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.
The Juno mission celebrated it’s 16th science pass of #Jupiter, marking the halfway point in data collection of the prime mission. Over the second half of the prime mission — science flybys 17 through 32 — the spacecraft will split the difference, flying exactly halfway between each previous orbit. This will provide coverage of the planet every 11.25 degrees of longitude, providing a more detailed picture of what makes the whole of Jupiter tick.
The Mars 2020 team had a workshop to discuss the newly announced landing site for our next rover on the Red Planet. The landing site…Jezero Crater! The goal of Mars 2020 is to learn whether life ever existed on Mars. It’s too cold and dry for life to exist on the Martian surface today. But after Jezero Crater formed billions of years ago, water filled it to form a deep lake about the same size as Lake Tahoe. Eventually, as Mars’ climate changed, Lake Jezero dried up. And surface water disappeared from the planet.
Humanity now has two interstellar ambassadors. On Nov. 5, 2018, our Voyager 2 spacecraft left the heliosphere — the bubble of the Sun’s magnetic influence formed by the solar wind. It’s only the second-ever human-made object to enter interstellar space, following its twin, Voyager 1, that left the heliosphere in 2012.
Scientists are especially excited to keep receiving data from Voyager 2, because — unlike Voyager 1 — its plasma science instrument is still working. That means we’ll learn brand-new information about what fills the space between the stars.
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. 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)!
In just four days this summer, miles of snow melted from
Lowell Glacier in Canada. Mauri Pelto, a glaciologist at Nichols College,
called the area of water-saturated snow a “snow swamp.”
These false-color images
show the rapid snow melt in Kluane National Park in the Yukon Territory. The
first image was taken on July 22, 2018, by the European Space Agency’s Sentinel-2;
the next image was acquired on July 26, 2018, by the Landsat 8 satellite.
Ice is shown as light blue, while meltwater is dark blue. On
July 26, the slush covered more than 25 square miles (40 square km).
During those four days, daily temperatures 40 miles (60 km)
northeast of the glacier reached 84 degrees Fahrenheit (29 degrees Celsius) —
much higher than normal for the region in July.
In 1910, glaciers covered at least 4 square miles (10 square
km) of the mountainous region of northwestern Venezuela. Today, less than one
percent of that ice remains, and all of it is locked up in one glacier. The
ongoing retreat of Humboldt Glacier—Venezuela’s last patch of perennial
ice—means that the country could soon be glacier-free.
The glacier is in the highest part of the Andes Mountains,
on a slope at nearly 16,000 feet. A cold
and snowy climate at high elevations is key for glaciers to exist in the
tropics. Most of Earth’s tropical glaciers are found in the Andes, which runs
through Venezuela, Colombia, Ecuador, Peru and Bolivia. But warming air temperatures
have contributed to their decline, including Humboldt Glacier.
The relatively recent changes to Humboldt are evident in
these images, acquired on Jan. 20, 1988, by the
United States Geological Survey’s Landsat 5 and on Jan. 6, 2015,
by Landsat 8. The images are false-color to better differentiate between areas
of snow and ice (blue), land (brown) and vegetation (green).
Scientists are trying to understand how long Humboldt will remain.
One said: “Let’s call it no more than 10 to 20 years.”
This year, we will launch two satellite missions that will increase our understanding of Earth’s frozen reaches. Snow, ice sheets, glaciers, sea ice and permafrost, known as the cryosphere, act as Earth’s thermostat and deep freeze, regulating temperatures by reflecting heat from the Sun and storing most of our fresh water.
2. GRACE-FO: Building on a Legacy and Forging Ahead
The next Earth science satellites set to launch are twins! The identical satellites of the GRACE Follow-On mission will build on the legacy of their predecessor GRACE by also tracking the ever-changing movement of water around our planet, including Earth’s frozen regions. GRACE-FO, a partnership between us and the German Research Center for Geosciences (GFZ), will provide critical information about how the Greenland and Antarctic ice sheets are changing. GRACE-FO, working together, will measure the distance between the two satellites to within 1 micron (much less than the width of a human hair) to determine the mass below.
Greenland has been losing about 280 gigatons of ice per year on average, and Antarctica has lost almost 120 gigatons a year with indications that both melt rates are increasing. A single gigaton of water would fill about 400,000 Olympic-sized swimming pools; each gigaton represents a billion tons of water.
3. ICESat-2: 10,000 Laser Pulses a Second
In September, we will launch ICESat-2, which uses a laser instrument to precisely measure the changing elevation of ice around the world, allowing scientists to see whether ice sheets and glaciers are accumulating snow and ice or getting thinner over time. ICESat-2 will also make critical measurements of the thickness of sea ice from space. Its laser instrument sends 10,000 pulses per second to the surface and will measure the photons’ return trip to satellite. The trip from ICESat-2 to Earth and back takes about 3.3 milliseconds.
4. Seeing Less Sea Ice
Summertime sea ice in the Arctic Ocean now routinely covers about 40% less area than it did in the late 1970s, when continuous satellite observations began. This kind of significant change could increase the rate of warming already in progress and affect global weather patterns.
5. The Snow We Drink
In the western United States, 1 in 6 people rely on snowpack for water. Our field campaigns such as the Airborne Snow Observatory and SnowEx seek to better understand how much water is held in Earth’s snow cover, and how we could ultimately measure this comprehensively from space.
6. Hidden in the Ground
Permafrost – permanently frozen ground in the Arctic that contains stores of heat-trapping gases such as methane and carbon dioxide – is thawing at faster rates than previously observed. Recent studies suggest that within three to four decades, this thawing could be releasing enough greenhouse gases to make Arctic permafrost a net source of carbon dioxide rather than a sink. Through airborne and field research on missions such as CARVE and ABoVE – the latter of which will put scientists back in the field in Alaska and Canada this summer – our scientists are trying to improve measurements of this trend in order to better predict global impact.
7. Breaking Records Over Cracking Ice
Last year was a record-breaking one for Operation IceBridge, our aerial survey of polar ice. For the first time in its nine-year history, the mission carried out seven field campaigns in the Arctic and Antarctic in a single year. In total, the IceBridge scientists and instruments flew over 214,000 miles, the equivalent of orbiting the Earth 8.6 times at the equator.
On March 22, we completed the first IceBridge flight of its spring Arctic campaign with a survey of sea ice north of Greenland. This year marks the 10th Arctic spring campaign for IceBridge. The flights continue until April 27 extending the mission’s decade-long mapping of the fastest-changing areas of the Greenland Ice Sheet and measuring sea ice thickness across the western Arctic basin.
Researchers were back in the field this month in Greenland with our Oceans Melting Greenland survey. The airborne and ship-based mission studies the ocean’s role in melting Greenland’s ice. Researchers examine temperatures, salinity and other properties of North Atlantic waters along the more than 27,000 miles (44,000 km) of jagged coastline.
9. DIY Glacier Modeling
Computer models are critical tools for understanding the future of a changing planet, including melting ice and rising seas. Our new sea level simulator lets you bury Alaska’s Columbia glacier in snow, and, year by year, watch how it responds. Or you can melt the Greenland and Antarctic ice sheets and trace rising seas as they inundate the Florida coast.
10. Ice Beyond Earth
Ice is common in our solar system. From ice packed into comets that cruise the solar system to polar ice caps on Mars to Europa and Enceladus-the icy ocean moons of Jupiter and Saturn-water ice is a crucial ingredient in the search for life was we know it beyond Earth.
Read the full version of this week’s 10 Things to Know HERE.
This Winter Olympics, our researchers are hoping for what a lot of Olympic athletes want in PyeongChang: precipitation and perfection.
Our researchers are measuring the quantity and type of snow falling on the slopes, tracks and halfpipes at the 2018 PyeongChang Winter Olympics and Paralympic games.
We are using ground instruments, satellite data and weather models to deliver detailed reports of current snow conditions and are testing experimental forecast models at 16 different points near Olympic event venues (shown below). The information is relayed every six hours to Olympic officials to help them account for approaching weather.
We are performing this research in collaboration with the Korea Meteorological Administration, as one of 20 agencies from about a dozen countries and the World Meteorological Organization’s World Weather Research Programme in a project called the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic Winter Games, or ICE-POP. The international team will make measurements from the start of the Olympics on Feb. 9 through the end of the Paralympics on March 18.
Image Credit: Republic of Korea
South Korea’s diverse terrain makes this project an exciting, albeit challenging, endeavor for scientists to study snow events. Ground instruments provide accurate snow observations in easily accessible surfaces, but not on uneven and in hard to reach mountainous terrain. A satellite in space has the ideal vantage point, but space measurements are difficult because snow varies in size, shape and water content. Those variables mean the snowflakes won’t fall at the same speed, making it hard to estimate the rates of snowfall. Snowflakes also have angles and planar “surfaces” that make it difficult for satellite radars to read.
The solution is to gather data from space and the ground and compare the measurements. We will track snowstorms and precipitation rates from space using the Global Precipitation Measurement mission, or GPM. The GPM Core Observatory is a joint mission between NASA and the Japan Aerospace Exploration Agency and coordinates with twelve other U.S. and international satellites to provide global maps of precipitation every 30 minutes (shown below).
We will complement the space data with 11 of our instruments observing weather from the ground in PyeongChang. These instruments are contributing to a larger international pool of measurements taken by instruments from the other ICE-POP participants: a total of 70 instruments deployed at the Olympics. We deployed the Dual-frequency, Dual-polarized, Doppler Radar system, usually housed at our Wallops Flight Facility in Virginia, to PyeongChang (shown below) that measures the quantity and types of falling snow.
The data will help inform Olympic officials about the current weather conditions, and will also be incorporated into the second leg of our research: improving weather forecast models. Our Marshall Space Flight Center’s Short-term Prediction Research and Transition Center (SPoRT) is teaming up with our Goddard Space Flight Center to use an advanced weather prediction model to provide weather forecasts in six-hour intervals over specific points on the Olympic grounds.
The above animation is our Unified Weather Research Forecast model (NU-WRF) based at Goddard. The model output shows a snow event on Jan. 14, 2018 in South Korea. The left animation labeled “precipitation type” shows where rain, snow, ice, and freezing rain are predicted to occur at each forecast time. The right labeled “surface visibility” is a measure of the distance that people can see ahead of them.
The SPoRT team will be providing four forecasts per day to the Korea Meteorological Administration, who will look at this model in conjunction with all the real-time forecast models in the ICE-POP campaign before relaying information to Olympic officials. The NU-WRF is one of five real-time forecast models running in the ICE-POP campaign.
For more information, watch the video below or read the entire story HERE.
They’ve packed extreme cold-weather gear and scientific instruments onto sleds pulled by two tank-like snow machines called PistenBullys, and after a stop at the South Pole Station (seen in this image), they began a two- to three-week traverse.
This traverse provides an extremely challenging way to assess the accuracy of the data. ICESat-2’s datasets are going to tell us incredible things about how Earth’s ice is changing, and what that means for things like sea level rise.