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By USH
While observing the Orion Nebula with his 12-inch Dobsonian telescope, a sky-watcher noticed an unusual flashing object. As stars appeared to drift due to Earth's rotation, this particular object while flashing approximately every 20 seconds clearly travels through deep space.
The observer wonders whether it might be a rotating satellite or not. However, this isn’t the first sighting of cigar-shaped UFOs or other mysterious objects traveling through space near the Orion Nebula, so it is quite possible that it could be an interstellar craft.
Over the years, I have shared several articles, complete with images and videos, documenting similar UFO sightings around the Orion Nebula. You can explore these under the tag: Orion Nebula.
Interestingly, these sightings have all occurred between November and February, suggesting there may be a seasonal pattern to these observations.
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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.”
News Media Contacts
Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
Written by Sally Younger
2024-147
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Last Updated Oct 29, 2024 Related Terms
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
A recent NASA-funded study quantified higher levels of fine particulate air pollution near Southern California warehouses, a result of emissions from diesel trucks that transport goods to and from such facilities. Inhalation of these tiny particles can cause serious health problems.Adobe Stock/Matt Gush Satellite-based data offers a broad view of particulate air pollution patterns across a major West Coast e-commerce hub.
As goods of all shapes and sizes journey from factory to doorstep, chances are they’ve stopped at a warehouse along the way — likely several of them. The sprawling structures are waypoints in the logistics networks that make e-commerce possible. Yet the convenience comes with tradeoffs, as illustrated in a recent NASA-funded study.
Published in the journal GeoHealth, the research analyzes patterns of particulate pollution in Southern California and found that ZIP codes with more or larger warehouses had higher levels of contaminants over time than those with fewer or smaller warehouses. Researchers focused on particulate pollution, choosing Southern California because it is a major distribution hub for goods: Its ports handle 40% of cargo containers entering the country.
The buildings themselves are not the major particulate sources. Rather, it’s the diesel trucks that pick up and drop off goods, emitting exhaust containing toxic particles called PM2.5. At 2.5 micrometers or less, these pollutants can be inhaled into the lungs and absorbed into the bloodstream. Although atmospheric concentrations are typically so small they’re measured in millionths of a gram per cubic meter, the authors caution that there’s no safe exposure level for PM2.5.
“Any increase in concentration causes some health damage,” said co-author Yang Liu, an environmental health researcher at Emory University in Atlanta. “But if you can curb pollution, there will be a measurable health benefit.”
A data visualization shows the average concentration of PM2.5 particulate pollution in the Los Angeles region from 2000 to 2018, along with the locations of nearly 11,000 warehouses. Darker red indicates higher concentration of these toxic particles; small black circles represent warehouse locations.NASA Earth Observatory Growing Air Quality Research
Particulate pollution has been linked to respiratory and cardiovascular diseases, some cancers, and adverse birth outcomes, including premature birth and low infant birth weight.
The new study is part of a broader effort funded by the NASA Health and Air Quality Applied Sciences Team to use satellite data to understand how air pollution disproportionately affects underserved communities.
As the e-commerce boom of recent decades has spurred warehouse construction, pollution in nearby neighborhoods has become a growing area for research. New structures have often sprouted on relatively inexpensive land, which tends to be home to low-income or minority populations who bear the brunt of the poor air quality, Liu said.
Another recent NASA-funded study analyzed satellite-derived nitrogen dioxide (NO2) measurements around 150,000 United States warehouses. It found that concentrations of the gas, which is a diesel byproduct and respiratory irritant, were about 20% higher near warehouses.
Distribution Hub
For the GeoHealth paper, scientists drew on previously generated datasets of PM2.5 from 2000 to 2018 and elemental carbon, a type of PM2.5 in diesel emissions, from 2000 to 2019. The data came from models based on satellite observations, including some from NASA’s MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) instruments.
The researchers also mined a real estate database for the square footage as well as the number of loading docks and parking spaces at nearly 11,000 warehouses across portions of Los Angeles, Riverside, and San Bernardino counties, and all of Orange County.
They found that warehouse capacity correlated with pollution. ZIP codes in the 75th percentile of warehouse square footage had 0.16 micrograms per cubic meter more PM2.5 and 0.021 micrograms per cubic meter more elemental carbon than those in the 25th percentile.
Similarly, ZIP codes in the 75th percentile of number of loading docks had 0.10 micrograms per cubic meter more PM2.5 and 0.014 micrograms per cubic meter more elemental carbon than those in the 25th percentile. And ZIP codes in the 75th percentile of truck parking spaces had 0.21 micrograms per cubic meter more PM2.5 and 0.021 micrograms per cubic meter more elemental carbon than those in the 25th percentile.
“We found that warehouses are associated with PM2.5 and elemental carbon,” said lead author Binyu Yang, an Emory environmental health doctoral student.
Although particulate pollution fell from 2000 to 2019 due to stricter emissions standards, the concentrations in ZIP codes with warehouses remained consistently higher than for other areas.
Researchers also found that the gaps widened in the holiday shopping season, up to 4 micrograms per cubic meter — “a significant difference,” Liu said.
Satellites Provide Big Picture
Satellite observations, the researchers said, were essential because they provided a continuous map of pollution, including pockets not covered by ground-based instruments.
It’s the same motivation behind NASA’s TEMPO (Tropospheric Emissions: Monitoring of Pollution) mission, which launched in April 2023 and measures air pollution hourly during daylight over North America. The release of TEMPO’s first maps showed higher concentrations of NO2 around cities and highways.
Meanwhile, NASA and the Italian Space Agency are collaborating to launch the MAIA (Multi-Angle Imager for Aerosols) in 2026. It will be the first NASA satellite mission whose primary goal is to study health effects of particulate pollution while distinguishing between PM2.5 types.
“This mission will help air quality managers and policymakers conceive more targeted pollution strategies,” said Sina Hasheminassab, a co-author and science systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. Hasheminassab, like Liu, is a member of the MAIA science team.
News Media Contacts
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
2024-134
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Last Updated Oct 09, 2024 Related Terms
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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
This image, taken from a data visualization, shows Arctic sea ice minimum extent on September 11, 2024. The yellow boundary shows the minimum extent averaged over the 30-year period from 1981 to 2010. Download high-resolution video and images from NASA’s Scientific Visualization Studio: https://svsdev.gsfc.nasa.gov/5382NASA’s Scientific Visualization Studio/Trent L. Schindler Arctic sea ice retreated to near-historic lows in the Northern Hemisphere this summer, likely melting to its minimum extent for the year on Sept.11, 2024, according to researchers at NASA and the National Snow and Ice Data Center (NSIDC). The decline continues the decades-long trend of shrinking and thinning ice cover in the Arctic Ocean.
The amount of frozen seawater in the Arctic fluctuates during the year as the ice thaws and regrows between seasons. Scientists chart these swings to construct a picture of how the Arctic responds over time to rising air and sea temperatures and longer melting seasons. Over the past 46 years, satellites have observed persistent trends of more melting in the summer and less ice formation in winter.
This summer, Arctic sea ice decreased to a its minimum extent on September 11, 2024. According to the National Snow and Ice Data Center this is the 7th lowest in the satellite record). The decline continues the long-term trend of shrinking ice cover in the Arctic Ocean.
Credit: NASA’s Goddard Space Flight Center Tracking sea ice changes in real time has revealed wide-ranging impacts, from losses and changes in polar wildlife habitat to impacts on local communities in the Arctic and international trade routes.
This year, Arctic sea ice shrank to a minimal extent of 1.65 million square miles (4.28 million square kilometers). That’s about 750,000 square miles (1.94 million square kilometers) below the 1981 to 2010 end-of-summer average of 2.4 million square miles (6.22 million square kilometers). The difference in ice cover spans an area larger than the state of Alaska. Sea ice extent is defined as the total area of the ocean with at least 15% ice concentration.
Seventh-Lowest in Satellite Record
This year’s minimum remained above the all-time low of 1.31 million square miles (3.39 million square kilometers) set in September 2012. While sea ice coverage can fluctuate from year to year, it has trended downward since the start of the satellite record for ice in the late 1970s. Since then, the loss of sea ice has been about 30,000 square miles (77,800 square kilometers) per year, according to NSIDC.
Scientists currently measure sea ice extent using data from passive microwave sensors aboard satellites in the Defense Meteorological Satellite Program, with additional historical data from the Nimbus-7 satellite, jointly operated by NASA and the National Oceanic and Atmospheric Administration (NOAA).
Today, the overwhelming majority of ice in the Arctic Ocean is thinner, first-year ice, which is less able to survive the warmer months. There is far, far less ice that is three years or older now,
Nathan Kurtz
Chief, NASA's Cryospheric Sciences Laboratory
Sea ice is not only shrinking, it’s getting younger, noted Nathan Kurtz, lab chief of NASA’s Cryospheric Sciences Laboratory at the agency’s Goddard Space Flight Center in Greenbelt, Maryland.
“Today, the overwhelming majority of ice in the Arctic Ocean is thinner, first-year ice, which is less able to survive the warmer months. There is far, far less ice that is three years or older now,” Kurtz said.
Ice thickness measurements collected with spaceborne altimeters, including NASA’s ICESat and ICESat-2 satellites, have found that much of the oldest, thickest ice has already been lost. New research out of NASA’s Jet Propulsion Laboratory in Southern California shows that in the central Arctic, away from the coasts, fall sea ice now hovers around 4.2 feet (1.3 meters) thick, down from a peak of 8.8 feet (2.7 meters) in 1980.
Another Meager Winter Around Antarctica
Sea ice in the southern polar regions of the planet was also low in 2024. Around Antarctica, scientists are tracking near record-low sea ice at a time when it should have been growing extensively during the Southern Hemisphere’s darkest and coldest months.
Ice around the continent is on track to be just over 6.6 million square miles (16.96 million square kilometers). The average maximum extent between 1981 and 2010 was 7.22 million square miles (18.71 million square kilometers).
The meager growth so far in 2024 prolongs a recent downward trend. Prior to 2014, sea ice in the Antarctic was increasing slightly by about 1% per decade. Following a spike in 2014, ice growth has fallen dramatically. Scientists are working to understand the cause of this reversal. The recurring loss hints at a long-term shift in conditions in the Southern Ocean, likely resulting from global climate change.
“While changes in sea ice have been dramatic in the Arctic over several decades, Antarctic sea ice was relatively stable. But that has changed,” said Walt Meier, a sea ice scientist at NSIDC. “It appears that global warming has come to the Southern Ocean.”
In both the Arctic and Antarctic, ice loss compounds ice loss. This is due to the fact that while bright sea ice reflects most of the Sun’s energy back to space, open ocean water absorbs 90% of it. With more of the ocean exposed to sunlight, water temperatures rise, further delaying sea ice growth. This cycle of reinforced warming is called ice-albedo feedback.
Overall, the loss of sea ice increases heat in the Arctic, where temperatures have risen about four times the global average, Kurtz said.
About the Author
Sally Younger
Senior Science Writer
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Last Updated Sep 24, 2024 LocationGoddard Space Flight Center Related Terms
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