Members Can Post Anonymously On This Site
JAMES WEBB Telescope Reveals EARLY UNIVERSE Secrets!
-
Similar Topics
-
-
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.
Share
Details
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
-
By NASA
5 Min Read Hats Off to NASA’s Webb: Sombrero Galaxy Dazzles in New Image
NASA’s James Webb Space Telescope recently imaged the Sombrero galaxy with its MIRI (Mid-Infrared Instrument), resolving the clumpy nature of the dust along the galaxy’s outer ring. Credits:
NASA, ESA, CSA, STScI In a new image from NASA’s James Webb Space Telescope, a galaxy named for its resemblance to a broad-brimmed Mexican hat appears more like an archery target.
In Webb’s mid-infrared view of the Sombrero galaxy, also known as Messier 104 (M104), the signature, glowing core seen in visible-light images does not shine, and instead a smooth inner disk is revealed. The sharp resolution of Webb’s MIRI (Mid-Infrared Instrument) also brings into focus details of the galaxy’s outer ring, providing insights into how the dust, an essential building block for astronomical objects in the universe, is distributed. The galaxy’s outer ring, which appeared smooth like a blanket in imaging from NASA’s retired Spitzer Space Telescope, shows intricate clumps in the infrared for the first time.
Image A: Sombrero Galaxy (MIRI Image)
NASA’s James Webb Space Telescope recently imaged the Sombrero galaxy with its MIRI (Mid-Infrared Instrument), resolving the clumpy nature of the dust along the galaxy’s outer ring. This image includes filters representing 7.7-micron light as blue, 11.3-micron light as green, and 12.8-micron light as red. NASA, ESA, CSA, STScI Image B: Sombrero Galaxy (Hubble and Webb Image)
Image Before/After Researchers say the clumpy nature of the dust, where MIRI detects carbon-containing molecules called polycyclic aromatic hydrocarbons, can indicate the presence of young star-forming regions. However, unlike some galaxies studied with Webb, including Messier 82, where 10 times as many stars are born than the Milky Way galaxy, the Sombrero galaxy is not a particular hotbed of star formation. The rings of the Sombrero galaxy produce less than one solar mass of stars per year, in comparison to the Milky Way’s roughly two solar masses a year.
Even the supermassive black hole, also known as an active galactic nucleus, at the center of the Sombrero galaxy is rather docile, even at a hefty 9-billion-solar masses. It’s classified as a low luminosity active galactic nucleus, slowly snacking on infalling material from the galaxy, while sending off a bright, relatively small, jet.
Also within the Sombrero galaxy dwell some 2,000 globular clusters, collections of hundreds of thousands of old stars held together by gravity. This type of system serves as a pseudo laboratory for astronomers to study stars — thousands of stars within one system with the same age, but varying masses and other properties is an intriguing opportunity for comparison studies.
In the MIRI image, galaxies of varying shapes and colors litter the background of space. The different colors of these background galaxies can tell astronomers about their properties, including how far away they are.
The Sombrero galaxy is around 30 million light-years from Earth in the constellation Virgo.
Video: Sombrero Galaxy Fade (Spitzer, Webb, Hubble)
A Bright Future Ahead
Stunning images like this, and an array of discoveries in the study of exoplanets, galaxies through time, star formation, and our own solar system, are still just the beginning. Recently, scientists from all over the world applied for observation time with Webb during its fourth year of science operations, which begins in July 2025.
General Observer time with Webb is more competitive than ever. A record-breaking 2,377 proposals were submitted by the Oct. 15, 2024, deadline, requesting about 78,000 hours of observation time. This is an oversubscription rate, the ratio defining the observation hours requested versus the actual time available in one year of Webb’s operations, of around 9 to 1.
The proposals cover a wide array of science topics, with distant galaxies being among the most requested observation time, followed by exoplanet atmospheres, stars and stellar populations, then exoplanet systems.
The Space Telescope Science Institute manages the proposal and program selection process for NASA. The submissions will now be evaluated by a Telescope Allocation Committee, a group of hundreds of members of the worldwide astronomical community, on a dual-anonymous basis, with selections announced in March 2025.
While time on Webb is limited, data from all of Webb’s programs is publicly archived, immediately after it’s taken, or after a time of exclusive access, in the Mikulski Archive for Space Telescopes (MAST) so it can be used by anyone in the world.
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).
Downloads
Right click any image to save it or open a larger version in a new tab/window via the browser’s popup menu.
View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
Media Contacts
Laura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Hannah Braun – hbraun@stsci.edu, Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Related Information
Article: Types of Galaxies
Video: Celestial Tour: Different types of galaxies
Article: Sombrero Galaxy’s Halo Suggests Turbulent Past
More images: Images of the Sombrero Galaxy in different types of light
Video: Sonification of Sombrero Galaxy images
More Webb News
More Webb Images
Webb Science Themes
Webb Mission Page
Related For Kids
What is a galaxy?
What is the Webb Telescope?
SpacePlace for Kids
En Español
¿Qué es una galaxia?
Ciencia de la NASA
NASA en español
Space Place para niños
Keep Exploring Related Topics
James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Galaxies
Galaxies Stories
Messier 104 (The Sombrero Galaxy)
Hubble easily resolves some of the Sombrero galaxy’s roughly 2,000 globular clusters.
Share
Details
Last Updated Nov 25, 2024 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
Astrophysics Galaxies Goddard Space Flight Center James Webb Space Telescope (JWST) Science & Research Spiral Galaxies The Universe View the full article
-
By European Space Agency
A new mid-infrared image from the NASA/ESA/CSA James Webb Space Telescope features the Sombrero galaxy, also known as Messier 104 (M104). The signature, glowing core seen in visible-light images does not shine, and instead a smooth inner disk is revealed. The sharp resolution of Webb’s MIRI (Mid-Infrared Instrument) also brings into focus details of the galaxy’s outer ring, providing insights into how the dust, an essential building block for astronomical objects in the Universe, is distributed. The galaxy’s outer ring shows intricate clumps in the infrared for the first time.
View the full article
-
By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Back to ESI Home
Computational Materials Engineering for Lunar Metals Welding
Azadeh Haghighi
University of Illinois, Chicago
Weld-ASSIST: Weldability Assessment for In-Space Conditions using a Digital Twin Wei Li
University of Texas at Dallas
Integrated Computational Materials Modelling Framework for Investigating the Process-Structure-Property Linkage of the Lunar Metal Welding with Internal Defects Passive Lunar Dust Control through Advanced Materials and Surface Engineering
SungWoo Nam
University of California, Irvine
Deformable Crumpled Nano-ball Coatings with Adaptable Adhesion and Mechanical Energy Absorption for Lunar Dust Mitigation Chih-Hao Chang
University of Texas at Austin
Engineering the Adhesion Mechanisms of Hierarchical Dust-Mitigating Nanostructures Lei Zhai
University of Central Florida
Studying Passive Dust Mitigation on Anisotropic Structured Surface Min Zou
University of Arkansas, Fayetteville
Developing High-Performance Bioinspired Surface Textures for Repelling Lunar Dust Keep Exploring Discover More Topics From STRG
Space Technology Mission Directorate
STMD Solicitations and Opportunities
Space Technology Research Grants
About STRG
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.