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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Healing continues in the atmosphere over the Antarctic: a hole that opens annually in the ozone layer over Earth’s southern pole was relatively small in 2024 compared to other years. Scientists with NASA and the National Oceanic and Atmospheric Administration (NOAA) project the ozone layer could fully recover by 2066.
This map shows the size and shape of the ozone hole over the South Pole on Sept. 28, 2024, the day of its annual maximum extent, as calculated by the NASA Ozone Watch team. Scientists describe the ozone “hole” as the area in which ozone concentrations drop below the historical threshold of 220 Dobson units. During the peak of ozone depletion season from Sept. 7 through Oct. 13, the 2024 area of the ozone hole ranked the seventh smallest since recovery began in 1992, when the Montreal Protocol, a landmark international agreement to phase out ozone-depleting chemicals, began to take effect.
At almost 8 million square miles (20 million square kilometers), the monthly average ozone-depleted region in the Antarctic this year was nearly three times the size of the contiguous U.S. The hole reached its greatest one-day extent for the year on Sept. 28 at 8.5 million square miles (22.4 million square kilometers).
The improvement is due to a combination of continuing declines in harmful chlorofluorocarbon (CFC) chemicals, along with an unexpected infusion of ozone carried by air currents from north of the Antarctic, scientists said.
The ozone hole over Antarctica reached its annual maximum extent on Sept. 28, 2024, with an area of 8.5 million square miles (22.4 million square kilometers).
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta In previous years, NASA and NOAA have reported the ozone hole ranking using a time frame dating back to 1979, when scientists began tracking Antarctic ozone levels with satellite data. Using that longer record, this year’s hole ranked 20th smallest in area across the 45 years of observations.
“The 2024 Antarctic hole is smaller than ozone holes seen in the early 2000s,” said Paul Newman, leader of NASA’s ozone research team and chief scientist for Earth sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The gradual improvement we’ve seen in the past two decades shows that international efforts that curbed ozone-destroying chemicals are working.”
The ozone-rich layer high in the atmosphere acts as a planetary sunscreen that helps shield us from harmful ultraviolet (UV) radiation from the Sun. Areas with depleted ozone allow more UV radiation, resulting in increased cases of skin cancer and cataracts. Excessive exposure to UV light can also reduce agricultural yields as well as damage aquatic plants and animals in vital ecosystems.
Scientists were alarmed in the 1970s at the prospect that CFCs could eat away at atmospheric ozone. By the mid-1980s, the ozone layer had been depleted so much that a broad swath of the Antarctic stratosphere was essentially devoid of ozone by early October each year. Sources of damaging CFCs included coolants in refrigerators and air conditioners, as well as aerosols in hairspray, antiperspirant, and spray paint. Harmful chemicals were also released in the manufacture of insulating foams and as components of industrial fire suppression systems.
The Montreal Protocol was signed in 1987 to phase out CFC-based products and processes. Countries worldwide agreed to replace the chemicals with more environmentally friendly alternatives by 2010. The release of CFC compounds has dramatically decreased following the Montreal Protocol. But CFCs already in the air will take many decades to break down. As existing CFC levels gradually decline, ozone in the upper atmosphere will rebound globally, and ozone holes will shrink.
Ozone 101 is the first in a series of explainer videos outlining the fundamentals of popular Earth science topics. Let’s back up to the basics and understand what caused the Ozone Hole, its effects on the planet, and what scientists predict will happen in future decades.
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta “For 2024, we can see that the ozone hole’s severity is below average compared to other years in the past three decades, but the ozone layer is still far from being fully healed,” said Stephen Montzka, senior scientist of the NOAA Global Monitoring Laboratory.
Researchers rely on a combination of systems to monitor the ozone layer. They include instruments on NASA’s Aura satellite, the NOAA-20 and NOAA-21 satellites, and the Suomi National Polar-orbiting Partnership satellite, jointly operated by NASA and NOAA.
NOAA scientists also release instrumented weather balloons from the South Pole Baseline Atmospheric Observatory to observe ozone concentrations directly overhead in a measurement called Dobson Units. The 2024 concentration reached its lowest value of 109 Dobson Units on October 5. The lowest value ever recorded over the South Pole was 92 Dobson Units in October 2006.
NASA and NOAA satellite observations of ozone concentrations cover the entire ozone hole, which can produce a slightly smaller value for the lowest Dobson Unit measurement.
“That is well below the 225 Dobson Units that was typical of the ozone cover above the Antarctic in 1979,” said NOAA research chemist Bryan Johnson. “So, there’s still a long way to go before atmospheric ozone is back to the levels before the advent of widespread CFC pollution.”
View the latest status of the ozone layer over the Antarctic with NASA’s ozone watch.
By James Riordon
NASA’s Earth Science News Team
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NASA’s Goddard Space Flight Center, Greenbelt, Md.
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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The Permafrost Tunnel north of Fairbanks, Alaska, was dug in the 1960s and is run by the U.S. Army’s Cold Regions Research and Engineering Laboratory. It is the site of much research into permafrost — ground that stays frozen throughout the year, for multiple years.NASA/Kate Ramsayer Earth’s far northern reaches have locked carbon underground for millennia. New research paints a picture of a landscape in change.
A new study, co-authored by NASA scientists, details where and how greenhouse gases are escaping from the Earth’s vast northern permafrost region as the Arctic warms. The frozen soils encircling the Arctic from Alaska to Canada to Siberia store twice as much carbon as currently resides in the atmosphere — hundreds of billions of tons — and most of it has been buried for centuries.
An international team, led by researchers at Stockholm University, found that from 2000 to 2020, carbon dioxide uptake by the land was largely offset by emissions from it. Overall, they concluded that the region has been a net contributor to global warming in recent decades in large part because of another greenhouse gas, methane, that is shorter-lived but traps significantly more heat per molecule than carbon dioxide.
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Greenhouse gases shroud the globe in this animation showing data from 2021. Carbon dioxide is shown in orange; methane is shown in purple. Methane traps heat 28 times more effectively than carbon dioxide over a 100-year timescale. Wetlands are a significant source of such emissions.NASA’s Scientific Visualization Studio The findings reveal a landscape in flux, said Abhishek Chatterjee, a co-author and scientist at NASA’s Jet Propulsion Laboratory in Southern California. “We know that the permafrost region has captured and stored carbon for tens of thousands of years,” he said. “But what we are finding now is that climate-driven changes are tipping the balance toward permafrost being a net source of greenhouse gas emissions.”
Carbon Stockpile
Permafrost is ground that has been permanently frozen for anywhere from two years to hundreds of thousands of years. A core of it reveals thick layers of icy soils enriched with dead plant and animal matter that can be dated using radiocarbon and other techniques. When permafrost thaws and decomposes, microbes feed on this organic carbon, releasing some of it as greenhouse gases.
Unlocking a fraction of the carbon stored in permafrost could further fuel climate change. Temperatures in the Arctic are already warming two to four times faster than the global average, and scientists are learning how thawing permafrost is shifting the region from being a net sink for greenhouse gases to becoming a net source of warming.
They’ve tracked emissions using ground-based instruments, aircraft, and satellites. One such campaign, NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE), is focused on Alaska and western Canada. Yet locating and measuring emissions across the far northern fringes of Earth remains challenging. One obstacle is the vast scale and diversity of the environment, composed of evergreen forests, sprawling tundra, and waterways.
This map, based on data provided by the National Snow and Ice Data Center, shows the extent of Arctic permafrost. The amount of permafrost underlying the surface ranges from continuous — in the coldest areas — to more isolated and sporadic patches.NASA Earth Observatory Cracks in the Sink
The new study was undertaken as part of the Global Carbon Project’s RECCAP-2 effort, which brings together different science teams, tools, and datasets to assess regional carbon balances every few years. The authors followed the trail of three greenhouse gases — carbon dioxide, methane, and nitrous oxide — across 7 million square miles (18 million square kilometers) of permafrost terrain from 2000 to 2020.
Researchers found the region, especially the forests, took up a fraction more carbon dioxide than it released. This uptake was largely offset by carbon dioxide emitted from lakes and rivers, as well as from fires that burned both forest and tundra.
They also found that the region’s lakes and wetlands were strong sources of methane during those two decades. Their waterlogged soils are low in oxygen while containing large volumes of dead vegetation and animal matter — ripe conditions for hungry microbes. Compared to carbon dioxide, methane can drive significant climate warming in short timescales before breaking down relatively quickly. Methane’s lifespan in the atmosphere is about 10 years, whereas carbon dioxide can last hundreds of years.
The findings suggest the net change in greenhouse gases helped warm the planet over the 20-year period. But over a 100-year period, emissions and absorptions would mostly cancel each other out. In other words, the region teeters from carbon source to weak sink. The authors noted that events such as extreme wildfires and heat waves are major sources of uncertainty when projecting into the future.
Bottom Up, Top Down
The scientists used two main strategies to tally greenhouse gas emissions from the region. “Bottom-up” methods estimate emissions from ground- and air-based measurements and ecosystem models. Top-down methods use atmospheric measurements taken directly from satellite sensors, including those on NASA’s Orbiting Carbon Observatory-2 (OCO-2) and JAXA’s (Japan Aerospace Exploration Agency)Greenhouse Gases Observing Satellite.
Regarding near-term, 20-year, global warming potential, both scientific approaches aligned on the big picture but differed in magnitude: The bottom-up calculations indicated significantly more warming.
“This study is one of the first where we are able to integrate different methods and datasets to put together this very comprehensive greenhouse gas budget into one report,” Chatterjee said. “It reveals a very complex picture.”
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Written by Sally Younger
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Last Updated Oct 29, 2024 Related Terms
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By NASA
Hubble Space Telescope Home Hubble Captures a New View of… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 2 min read
Hubble Captures a New View of Galaxy M90
This eye-catching image offers us a new view of the spiral galaxy Messier 90 from the NASA/ESA Hubble Space Telescope. ESA/Hubble & NASA, D. Thilker, J This NASA/ESA Hubble Space Telescope image features the striking spiral galaxy Messier 90 (M90, also NGC 4569), located in the constellation Virgo. In 2019, Hubble released an image of M90 created with Wide Field and Planetary Camera 2 (WFPC2) data taken in 1994, soon after its installation. That WFPC2 image has a distinctive stair-step pattern due to the layout of its sensors. Wide Field Camera 3 (WFC3) replaced WFPC2 in 2009 and Hubble used WFC3 when it turned its aperture to Messier 90 again in 2019 and 2023. That data resulted in this stunning new image, providing a much fuller view of the galaxy’s dusty disk, its gaseous halo, and its bright core.
The inner regions of M90’s disk are sites of star formation, seen here in red H-alpha light from nebulae. M90 sits among the galaxies of the relatively nearby Virgo Cluster, and its orbit took M90 on a path near the cluster’s center about three hundred million years ago. The density of gas in the inner cluster weighed on M90 like a strong headwind, stripping enormous quantities of gas from the galaxy and creating the diffuse halo we see around it. This gas is no longer available to form new stars in M90, with the spiral galaxy eventually fading as a result.
M90 is located 55 million light-years from Earth, but it’s one of the very few galaxies getting closer to us. Its orbit through the Virgo cluster has accelerated so much that M90 is in the process of escaping the cluster entirely. By happenstance, it’s moving in our direction. Astronomers have measured other galaxies in the Virgo cluster at similar speeds, but in the opposite direction. As M90 continues to move toward us over billions of years, it will also be evolving into a lenticular galaxy.
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Last Updated Oct 17, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
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This beautiful spiral is expected to evolve into a lenticular galaxy.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
New findings using data from NASA’s IXPE (Imaging X-ray Polarimetry Explorer) mission offer unprecedented insight into the shape and nature of a structure important to black holes called a corona.
A corona is a shifting plasma region that is part of the flow of matter onto a black hole, about which scientists have only a theoretical understanding. The new results reveal the corona’s shape for the first time, and may aid scientists’ understanding of the corona’s role in feeding and sustaining black holes.
This illustration of material swirling around a black hole highlights a particular feature, called the “corona,” that shines brightly in X-ray light. In this depiction, the corona can be seen as a purple haze floating above the underlying accretion disk, and extending slightly inside of its inner edge. The material within the inner accretion disk is incredibly hot and would glow with a blinding blue-white light, but here has been reduced in brightness to make the corona stand out with better contrast. Its purple color is purely illustrative, standing in for the X-ray glow that would not be obvious in visible light. The warp in the disk is a realistic representation of how the black hole’s immense gravity acts like an optical lens, distorting our view of the flat disk that encircles it. NASA/Caltech-IPAC/Robert Hurt Many black holes, so named because not even light can escape their titanic gravity, are surrounded by accretion disks, debris-cluttered whirlpools of gas. Some black holes also have relativistic jets – ultra-powerful outbursts of matter hurled into space at high speed by black holes that are actively eating material in their surroundings.
Less well known, perhaps, is that snacking black holes, much like Earth’s Sun and other stars, also possess a superheated corona. While the Sun’s corona, which is the star’s outermost atmosphere, burns at roughly 1.8 million degrees Fahrenheit, the temperature of a black hole corona is estimated at billions of degrees.
Astrophysicists previously identified coronae among stellar-mass black holes – those formed by a star’s collapse – and supermassive black holes such as the one at the heart of the Milky Way galaxy.
“Scientists have long speculated on the makeup and geometry of the corona,” said Lynne Saade, a postdoctoral researcher at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and lead author of the new findings. “Is it a sphere above and below the black hole, or an atmosphere generated by the accretion disk, or perhaps plasma located at the base of the jets?”
Enter IXPE, which specializes in X-ray polarization, the characteristic of light that helps map the shape and structure of even the most powerful energy sources, illuminating their inner workings even when the objects are too small, bright, or distant to see directly. Just as we can safely observe the Sun’s corona during a total solar eclipse, IXPE provides the means to clearly study the black hole’s accretion geometry, or the shape and structure of its accretion disk and related structures, including the corona.
“X-ray polarization provides a new way to examine black hole accretion geometry,” Saade said. “If the accretion geometry of black holes is similar regardless of mass, we expect the same to be true of their polarization properties.”
IXPE demonstrated that, among all black holes for which coronal properties could be directly measured via polarization, the corona was found to be extended in the same direction as the accretion disk – providing, for the first time, clues to the corona’s shape and clear evidence of its relationship to the accretion disk. The results rule out the possibility that the corona is shaped like a lamppost hovering over the disk.
The research team studied data from IXPE’s observations of 12 black holes, among them Cygnus X-1 and Cygnus X-3, stellar-mass binary black hole systems about 7,000 and 37,000 light-years from Earth, respectively, and LMC X-1 and LMC X-3, stellar-mass black holes in the Large Magellanic Cloud more than 165,000 light-years away. IXPE also observed a number of supermassive black holes, including the one at the center of the Circinus galaxy, 13 million light-years from Earth, and those in galaxies NGC 1068 and NGC 4151, 47 million light-years away and nearly 62 million light-years away, respectively.
Stellar mass black holes typically have a mass roughly 10 to 30 times that of Earth’s Sun, whereas supermassive black holes may have a mass that is millions to tens of billions of times larger. Despite these vast differences in scale, IXPE data suggests both types of black holes create accretion disks of similar geometry.
That’s surprising, said Marshall astrophysicist Philip Kaaret, principal investigator for the IXPE mission, because the way the two types are fed is completely different.
“Stellar-mass black holes rip mass from their companion stars, whereas supermassive black holes devour everything around them,” he said. “Yet the accretion mechanism functions much the same way.”
That’s an exciting prospect, Saade said, because it suggests that studies of stellar-mass black holes – typically much closer to Earth than their much more massive cousins – can help shed new light on properties of supermassive black holes as well.
The team next hopes to make additional examinations of both types.
Saade anticipates there’s much more to glean from X-ray studies of these behemoths. “IXPE has provided the first opportunity in a long time for X-ray astronomy to reveal the underlying processes of accretion and unlock new findings about black holes,” she said.
The complete findings are available in the latest issue of The Astrophysical Journal.
More about IXPE
IXPE, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. IXPE is led by Marshall. Ball Aerospace, headquartered in Broomfield, Colorado, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder.
Learn more about IXPE’s ongoing mission here:
https://www.nasa.gov/ixpe
Elizabeth Landau
NASA Headquarters
elizabeth.r.landau@nasa.gov
202-358-0845
Lane Figueroa
NASA’s Marshall Space Flight Center
256-544-0034
lane.e.figueroa@nasa.gov
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Last Updated Oct 17, 2024 EditorBeth RidgewayLocationMarshall Space Flight Center Related Terms
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Dr. Rickey Shyne is responsible for leading a staff of approximately 1,100 engineers and scientists.Credit: NASA Dr. Rickey J. Shyne, director of Research and Engineering at NASA’s Glenn Research Center in Cleveland, has been named one of Crain’s Cleveland Business’ 2024 Notable Black Leaders.
Shyne is responsible for leading a staff of approximately 1,100 engineers and scientists, and managing research and development in propulsion, communications, power, and materials and structures for extreme environments in support of the agency’s missions. He is on the board of Southwest General Health Center and a former board member of Cleveland Engineering Society.
Crain’s Notable Black Leaders represent all industries and communities. From magnates to mentors, they are working to enrich their companies, communities and city. Nominees must serve in a senior leadership role at their company or organization; have at least five years of experience in their field; and demonstrate significant accomplishments within their industry, professional organizations, and civic and community groups. They must live and work in the Northeast Ohio area.
Shyne is featured in the Crain’s September 30 issue, online and in print.
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