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By NASA
Illustration of the main asteroid belt, orbiting the Sun between Mars and JupiterNASA NASA’s powerful James Webb Space Telescope includes asteroids on its list of objects studied and secrets revealed.
A team led by researchers at the Massachusetts Institute of Technology (MIT) in Cambridge repurposed Webb’s observations of a distant star to reveal a population of small asteroids — smaller than astronomers had ever detected orbiting the Sun in the main asteroid belt between Mars and Jupiter.
The 138 new asteroids range from the size of a bus to the size of a stadium — a size range in the main belt that has not been observable with ground-based telescopes. Knowing how many main belt asteroids are in different size ranges can tell us something about how asteroids have been changed over time by collisions. That process is related to how some of them have escaped the main belt over the solar system’s history, and even how meteorites end up on Earth.
“We now understand more about how small objects in the asteroid belt are formed and how many there could be,” said Tom Greene, an astrophysicist at NASA’s Ames Research Center in California’s Silicon Valley and co-author on the paper presenting the results. “Asteroids this size likely formed from collisions between larger ones in the main belt and are likely to drift towards the vicinity of Earth and the Sun.”
Insights from this research could inform the work of the Asteroid Threat Assessment Project at Ames. ATAP works across disciplines to support NASA’s Planetary Defense Coordination Office by studying what would happen in the case of an Earth impact and modeling the associated risks.
“It’s exciting that Webb’s capabilities can be used to glean insights into asteroids,” said Jessie Dotson, an astrophysicist at Ames and member of ATAP. “Understanding the sizes, numbers, and evolutionary history of smaller main belt asteroids provides important background about the near-Earth asteroids we study for planetary defense.”
Illustration of the James Webb Space TelescopeNASA The team that made the asteroid detections, led by research scientist Artem Burdanov and professor of planetary science Julien de Wit, both of MIT, developed a method to analyze existing Webb images for the presence of asteroids that may have been inadvertently “caught on film” as they passed in front of the telescope. Using the new image processing technique, they studied more than 10,000 images of the star TRAPPIST-1, originally taken to search for atmospheres around planets orbiting the star, in the search for life beyond Earth.
Asteroids shine more brightly in infrared light, the wavelength Webb is tuned to detect, than in visible light, helping reveal the population of main belt asteroids that had gone unnoticed until now. NASA will also take advantage of that infrared glow with an upcoming mission, the Near-Earth Object (NEO) Surveyor. NEO Surveyor is the first space telescope specifically designed to hunt for near-Earth asteroids and comets that may be potential hazards to Earth.
The paper presenting this research, “Detections of decameter main-belt asteroids with JWST,” was published Dec. 9 in Nature.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
For news media:
Members of the news media interested in covering this topic should reach out to the NASA Ames newsroom.
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By NASA
4 min read
NASA Open Science Reveals Sounds of Space
A composite image of the Crab Nebula features X-rays from Chandra (blue and white), optical data from Hubble (purple), and infrared data from Spitzer (pink). This image is one of several that can be experienced as a sonification through Chandra’s Universe of Sound project. X-ray: NASA/CXC/SAO; Optical: NASA/STScI; Infrared: NASA-JPL-Caltech NASA has a long history of translating astronomy data into beautiful images that are beloved by the public. Through its Chandra X-ray Observatory and Universe of Learning programs, NASA brings that principle into the world of audio in a project known as “A Universe of Sound.” The team has converted openly available data from Chandra, supplemented by open data from other observatories, into dozens of “sonifications,” with more on the way.
Following the open science principle of accessibility, “A Universe of Sound” helps members of the public who are blind or low vision experience NASA data in a new sensory way. Sighted users also enjoy listening to the sonifications.
“Open science is this way to not just have data archives that are accessible and incredibly rich, but also to enhance the data outputs themselves,” said Dr. Kimberly Arcand, the visualization scientist and emerging technology lead at Chandra and member of NASA’s Universe of Learning who heads up the sonification team. “I want everybody to have the same type of access to this data that I do as a scientist. Sonification is just one of those steps.”
Data sonification of the Milky Way galactic center, made using data from NASA’s Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer Space Telescope. While the Chandra telescope provides data in X-ray wavelengths for most of the sonifications, the team also took open data from other observatories to create a fuller picture of the universe. Types of data used to create some of the sonifications include visual and ultraviolet light from the Hubble Space Telescope, infrared and visual light from the James Webb Space Telescope, and infrared light from the now-retired Spitzer Space Telescope.
The sonification team, which includes astrophysicist Matt Russo, musician Andrew Santaguida (both of the SYSTEM Sounds project), consultant Christine Malec, and Dr. Arcand, assigned each wavelength of observation to a different musical instrument or synthesized sound to create a symphony of data. Making the separate layers publicly available was important to the team to help listeners understand the data better.
“It’s not just about accessibility. It’s also about reproducibility,” Arcand said. “We’re being very specific with providing all of the layers of sound, and then describing what those layers are doing to make it more transparent and obvious which steps were taken and what process of translation has occurred.”
For example, in a sonification of the supernova remnant Cassiopeia A, modified piano sounds represent X-ray data from Chandra, strings and brass represent infrared data from Webb and Spitzer, and small cymbals represent stars located via visual light data from Hubble.
Data sonification of the Cassiopeia A supernova remnant, made using data from NASA’s Chandra X-ray Observatory, James Webb Space Telescope, and Hubble Space Telescope. The team brought together people of various backgrounds to make the project a success – scientists to obtain and interpret the data, audio engineers to mix the sonifications, and members of the blind and low vision community to direct the product into something that brought a greater understanding of the data.
“Another benefit to open science is it tends to open those pathways of collaboration,” Arcand said. “We invite lots of different community members into the process to make sure we’re creating something that adds value, that adds to the greater good, and that makes the investment in the data worthwhile.”
A documentary about the sonifications called “Listen to the Universe” is hosted on NASA+. Visitors can listen to all the team’s sonifications, including the separate layers from each wavelength of observation, on the Universe of Sound website.
By Lauren Leese
Web Content Strategist for the Office of the Chief Science Data Officer
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Last Updated Dec 17, 2024 Related Terms
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By European Space Agency
Launched in May 2024, ESA’s EarthCARE satellite is nearing the end of its commissioning phase with the release of its first data on clouds and aerosols expected early next year. In the meantime, an international team of scientists has found an innovative way of applying artificial intelligence to other satellite data to yield 3D profiles of clouds.
This is particularly news for those eagerly awaiting data from EarthCARE in their quest to advance climate science.
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By European Space Agency
On 1 December 2024, BepiColombo flew past Mercury for the fifth time. During this flyby, BepiColombo became the first spacecraft ever to observe Mercury in mid-infrared light. The new images reveal variations in temperature and composition across the planet's cratered surface.
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By NASA
As any urban dweller who has lived through a heat wave knows, a shady tree can make all the difference. But what happens when there’s no shade available?
A recent study in Nature Communications used NASA satellite data to identify a major gap in global resilience to climate change: cities in the Global South have far less green space — and therefore less cooling capacity — than cities in the Global North. The terms Global North and Global South were used in the study to distinguish developed countries (mostly in the Northern Hemisphere) from developing nations (mostly in the Southern Hemisphere).
Cities tend to be hotter than nearby rural areas because of the urban heat island effect. Heat-trapping dark surfaces such as sidewalks, buildings, and roads absorb heat from the Sun’s rays, which raises the temperature of the city. Extreme heat poses serious health threats for urban residents, including dehydration, heat stroke, and even death. Though not a cure-all, greenery provides shade and releases moisture into the air, cooling the surroundings.
“Cities can strategically prioritize developing new green spaces in areas that have less green space,” said Christian Braneon, a climate scientist at NASA’s Goddard Institute for Space Studies in New York who was not affiliated with this study. “Satellite data can be really helpful for this.”
The Operational Land Imager (OLI) on the NASA and U.S. Geological Survey’s Landsat 8 satellite captured this natural color image of Sanaa, Yemen, on June 8, 2024. Sanaa, which has a hot, dry climate and little green space, had the second-lowest cooling capacity of 500 cities studied in a paper recently published in the journal Nature Communications. Wanmei Liang, NASA Earth Observatory An international team of researchers led by Yuxiang Li, a doctoral student at Nanjing University, analyzed the 500 largest cities in the world to compare their cooling capacities. They used data from the Landsat 8 satellite, jointly managed by NASA and the U.S. Geological Survey, to determine how effective green space was at cooling each city.
First, they calculated the average land surface temperature for the hottest month of 2018 for each city, as well as the average of the hottest months from 2017 to 2019. Next, the researchers used a metric called the Normalized Difference Vegetation Index (NDVI) to map how much green space each city had. The NDVI relies on the fact that healthy vegetation absorbs red light and reflects infrared light: the ratio of these wavelengths can show the density of healthy vegetation in a given satellite image.
Researchers found that cities in the Global South have just 70% of the greenery-related cooling capacity of cities in the Global North. The green spaces in an average Global South city cool the temperature by about 4.5 F (2.5 C). In an average Global North city, that cooling capacity is 6.5 F (3.6 C). This compounds an existing problem: cities in the South tend to be at lower latitudes (that is, nearer to the Equator), which are predicted to see more heat extremes in the coming years.
“It’s already clear that Global South countries will be impacted by heat waves, rising temperatures, and climatic extremes more than their Global North counterparts,” said Chi Xu, a professor of ecology at Nanjing University and a co-author of the study. The Global South has less capacity to adapt to heat because air conditioning is less common and power outages are more frequent.
Why do cities in the Global South struggle to stay cool? Cities in the Global South tend to have less green space than cities in the Global North. This mirrors studies of the disparities within cities, sometimes referred to as the “luxury effect”: wealthier neighborhoods tend to have more green space than poorer neighborhoods. “Wealthier cities also have more urban green spaces than the poorest cities,” Chi said.
It’s unlikely that urban planners can close the gap between the study’s worst-performing city (Mogadishu, Somalia) and the best-performing one (Charlotte, North Carolina).
Mogadishu is a dense city with a dry climate that limits vegetation growth. Still, there’s a lot that each city can learn from its neighbors. Within a given region, the researchers identified the city with the greatest cooling capacity and used that as a goal. They calculated the difference between the best-performing city in the region and every city nearby to get the potential additional cooling capacity. They found that cities’ average cooling capacity could be increased substantially — to as much as 18 F (10 C) — by systematically increasing green space quantity and quality.
“How you utilize green space is really going to vary depending on the climate and the urban environment you’re focused on,” said Braneon, whose research at NASA focuses on climate change and urban planning.
Greener cities in the U.S. and Canada have lower population densities. However, fewer people per square mile isn’t necessarily good for the environment: residents in low-density cities rely more on cars, and their houses tend to be bigger and less efficient. Braneon noted that there’s a suite of solutions beyond just planting trees or designating parks: Cities can increase cooling capacity by creating water bodies, seeding green roofs, and painting roofs or pavement lighter colors to reflect more light.
With a global study like this, urban planners can compare strategies for cities within the same region or with similar densities. “For newly urbanized areas that aren’t completely built out, there’s a lot of room to still change the design,” Braneon said.
By Madeleine Gregory
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Nov 26, 2024 Editor Rob Garner Contact Rob Garner rob.garner@nasa.gov Location Goddard Space Flight Center Related Terms
Climate Change Earth Goddard Institute for Space Studies Goddard Space Flight Center Landsat Landsat 8 / LDCM (Landsat Data Continuity Mission) View the full article
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