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By NASA
Earth (ESD) Earth Explore Explore Earth Home Air Quality Climate Change Freshwater Life on Earth Severe Storms Snow and Ice The Global Ocean Science at Work Earth Science at Work Technology and Innovation Powering Business Multimedia Image Collections Videos Data For Researchers About Us 4 min read
NASA-Assisted Scientists Get Bird’s-Eye View of Population Status
Through the eBird citizen scientist program, millions of birders have recorded their observations of different species and submitted checklists to the Cornell Lab of Ornithology. Through a partnership with NASA, the lab has now used this data to model and map bird population trends for nearly 500 North American species.
Led by Alison Johnston of the University of St. Andrews in Scotland, the researchers reported that 75% of bird species in the study are declining at wide-range scales. And yet this study has some good news for birds. The results, published in Science in May, offer insights and projections that could shape the future conservation of the places where birds make their homes.
“This project demonstrates the power of merging in situ data with NASA remote sensing to model biological phenomena that were previously impossible to document,” said Keith Gaddis, NASA’s Biological Diversity and Ecological Forecasting program manager at the agency’s headquarters in Washington, who was not involved in the study. “This data provides not just insight into the Earth system but also provides actionable guidance to land managers to mitigate biodiversity loss.”
Rock wren in Joshua Tree National Park. National Park Service / Jane Gamble A team from Cornell, the University of St. Andrews, and the American Bird Conservancy used land imaging data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instruments to distinguish among such specific bird habitats as open forests, dense shrublands, herbaceous croplands, and forest/cropland mosaics. They also drew on NASA weather information and water data that matched the dates and times when birders made their reports.
When combined with a 14-year set of eBird checklists — 36 million sets of species observations and counts, keyed directly to habitats — the satellite data gave researchers almost a strong foundation to produce a clear picture of the health of bird populations. But there was one missing piece.
Wrestling with Wren Data
While some eBird checklists come from expert birders who’ve hiked deep into wildlife preserves, others are sent in by novices watching bird feeders and doing the dishes. This creates what Cornell statistician Daniel Fink described as “an unstructured, very noisy data set,” complete with gaps in the landscape that birders did not reach and, ultimately, some missing birds.
To account for gaps where birds weren’t counted, the researchers trained machine learning models to fill in the maps based on the remote sensing data. “For every single species — say the rock wren — we’ve created a simulation that mimics the species and a variety of ways that it could respond to changes in the environment,” Johnston said. “Thousands of simulations underlie the results we showed.”
CornellLab eBird The researchers achieved unprecedented resolution, zeroing in on areas 12 miles by 12 miles (27 km by 27 km), the same area as Portland, Oregon. This new population counting method can also be applied to eBird data from other locations, Fink said. “Now we’re using modeling to track bird populations — not seasonally through the year, but acrossthe years — a major milestone,” he added.
“We’ve been able to take citizen science data and, through machine learning methodology, put it on the same footing as traditionally structured surveys, in terms of the type of signal we can find,” said Cornell science product manager Tom Auer. “It will increase the credibility and confidence of people who use this information for precise conservation all over the globe.”
The Up Side
Since 1970, North America has lost one-quarter of its breeding birds, following a global trend of declines across species. The causes range from increased pollution and land development to changing climate and decreased food resources. Efforts to reverse this loss depend on identifying the areas where birds live at highest risk, assessing their populations, and pinpointing locations where conservation could help most.
For 83% of the reported species in the new study, the decline was greatest in spots where populations had previously been most abundant — indicating problems with the habitat.
“Even in species where populations are declining a lot, there are still places of hope, where the populations are going up,” Johnston said. The team found population increases in the maps of 97% of the reported species. “That demonstrates that there’s opportunity for those species.”
“Birds face so many challenges,” said Cornell conservationist Amanda Rodewald. “This research will help us make strategic decisions about making changes that are precise, effective, and less costly. This is transformative. Now we can really drill in and know where specifically we’re going to be able to have the most positive impact in trying to stem bird declines.”
By Karen Romano Young
NASA Headquarters, Washington
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Last Updated Jun 25, 2025 Related Terms
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By European Space Agency
Video: 00:17:03 Watch the replay of the ESA-European Commission press conference with Josef Aschbacher, Director General of ESA, and Andrius Kubilius, EU Commissioner for Defence and Space, held at the Paris Air Show 2025 (Le Bourget) on 18 June 2025.
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By NASA
Attendees line up to enter the theater for a screening of the new NASA+ documentary “Cosmic Dawn: The Untold Story of the James Webb Space Telescope,” Wednesday, June 11, 2025, at the Greenbelt Cinema in Greenbelt, Maryland. Featuring never-before-seen footage, Cosmic Dawn offers an unprecedented glimpse into the assembly, testing, and launch of NASA’s James Webb Space Telescope.NASA/Joel Kowsky Attendees line up to enter the theater for a screening of the new NASA+ documentary “Cosmic Dawn: The Untold Story of the James Webb Space Telescope,” Wednesday, June 11, 2025, at the Greenbelt Cinema in Greenbelt, Maryland. Following the screening, Jacob Pinter, host of NASA’s Curious Universe podcast, led a discussion with Sophia Roberts, a NASA video producer who documented the Webb project, and Paul Geithner, former deputy project manager for Webb.
Featuring never-before-seen footage, Cosmic Dawn offers an unprecedented glimpse into the assembly, testing, and launch of NASA’s James Webb Space Telescope.
Watch the documentary.
Image credit: NASA/Joel Kowsky
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By NASA
A funky effect Einstein predicted, known as gravitational lensing — when a foreground galaxy magnifies more distant galaxies behind it — will soon become common when NASA’s Nancy Grace Roman Space Telescope begins science operations in 2027 and produces vast surveys of the cosmos.
This image shows a simulated observation from NASA’s Nancy Grace Roman Space Telescope with an overlay of its Wide Field Instrument’s field of view. More than 20 gravitational lenses, with examples shown at left and right, are expected to pop out in every one of Roman’s vast observations. A journal paper led by Bryce Wedig, a graduate student at Washington University in St. Louis, Missouri, estimates that of those Roman detects, about 500 from the telescope’s High-Latitude Wide-Area Survey will be suitable for dark matter studies. By examining such a large population of gravitational lenses, the researchers hope to learn a lot more about the mysterious nature of dark matter.Credit: NASA, Bryce Wedig (Washington University), Tansu Daylan (Washington University), Joseph DePasquale (STScI) A particular subset of gravitational lenses, known as strong lenses, is the focus of a new paper published in the Astrophysical Journal led by Bryce Wedig, a graduate student at Washington University in St. Louis. The research team has calculated that over 160,000 gravitational lenses, including hundreds suitable for this study, are expected to pop up in Roman’s vast images. Each Roman image will be 200 times larger than infrared snapshots from NASA’s Hubble Space Telescope, and its upcoming “wealth” of lenses will vastly outpace the hundreds studied by Hubble to date.
Roman will conduct three core surveys, providing expansive views of the universe. This science team’s work is based on a previous version of Roman’s now fully defined High-Latitude Wide-Area Survey. The researchers are working on a follow-up paper that will align with the final survey’s specifications to fully support the research community.
“The current sample size of these objects from other telescopes is fairly small because we’re relying on two galaxies to be lined up nearly perfectly along our line of sight,” Wedig said. “Other telescopes are either limited to a smaller field of view or less precise observations, making gravitational lenses harder to detect.”
Gravitational lenses are made up of at least two cosmic objects. In some cases, a single foreground galaxy has enough mass to act like a lens, magnifying a galaxy that is almost perfectly behind it. Light from the background galaxy curves around the foreground galaxy along more than one path, appearing in observations as warped arcs and crescents. Of the 160,000 lensed galaxies Roman may identify, the team expects to narrow that down to about 500 that are suitable for studying the structure of dark matter at scales smaller than those galaxies.
“Roman will not only significantly increase our sample size — its sharp, high-resolution images will also allow us to discover gravitational lenses that appear smaller on the sky,” said Tansu Daylan, the principal investigator of the science team conducting this research program. Daylan is an assistant professor and a faculty fellow at the McDonnell Center for the Space Sciences at Washington University in St. Louis. “Ultimately, both the alignment and the brightness of the background galaxies need to meet a certain threshold so we can characterize the dark matter within the foreground galaxies.”
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This video shows how a background galaxy’s light is lensed or magnified by a massive foreground galaxy, seen at center, before reaching NASA’s Roman Space Telescope. Light from the background galaxy is distorted, curving around the foreground galaxy and appearing more than once as warped arcs and crescents. Researchers studying these objects, known as gravitational lenses, can better characterize the mass of the foreground galaxy, which offers clues about the particle nature of dark matter.Credit: NASA, Joseph Olmsted (STScI) What Is Dark Matter?
Not all mass in galaxies is made up of objects we can see, like star clusters. A significant fraction of a galaxy’s mass is made up of dark matter, so called because it doesn’t emit, reflect, or absorb light. Dark matter does, however, possess mass, and like anything else with mass, it can cause gravitational lensing.
When the gravity of a foreground galaxy bends the path of a background galaxy’s light, its light is routed onto multiple paths. “This effect produces multiple images of the background galaxy that are magnified and distorted differently,” Daylan said. These “duplicates” are a huge advantage for researchers — they allow multiple measurements of the lensing galaxy’s mass distribution, ensuring that the resulting measurement is far more precise.
Roman’s 300-megapixel camera, known as its Wide Field Instrument, will allow researchers to accurately determine the bending of the background galaxies’ light by as little as 50 milliarcseconds, which is like measuring the diameter of a human hair from the distance of more than two and a half American football fields or soccer pitches.
The amount of gravitational lensing that the background light experiences depends on the intervening mass. Less massive clumps of dark matter cause smaller distortions. As a result, if researchers are able to measure tinier amounts of bending, they can detect and characterize smaller, less massive dark matter structures — the types of structures that gradually merged over time to build up the galaxies we see today.
With Roman, the team will accumulate overwhelming statistics about the size and structures of early galaxies. “Finding gravitational lenses and being able to detect clumps of dark matter in them is a game of tiny odds. With Roman, we can cast a wide net and expect to get lucky often,” Wedig said. “We won’t see dark matter in the images — it’s invisible — but we can measure its effects.”
“Ultimately, the question we’re trying to address is: What particle or particles constitute dark matter?” Daylan added. “While some properties of dark matter are known, we essentially have no idea what makes up dark matter. Roman will help us to distinguish how dark matter is distributed on small scales and, hence, its particle nature.”
Preparations Continue
Before Roman launches, the team will also search for more candidates in observations from ESA’s (the European Space Agency’s) Euclid mission and the upcoming ground-based Vera C. Rubin Observatory in Chile, which will begin its full-scale operations in a few weeks. Once Roman’s infrared images are in hand, the researchers will combine them with complementary visible light images from Euclid, Rubin, and Hubble to maximize what’s known about these galaxies.
“We will push the limits of what we can observe, and use every gravitational lens we detect with Roman to pin down the particle nature of dark matter,” Daylan said.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Melbourne, Florida; and Teledyne Scientific & Imaging in Thousand Oaks, California.
By Claire Blome
Space Telescope Science Institute, Baltimore, Md.
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Last Updated Jun 12, 2025 EditorAshley BalzerContactAshley Balzerashley.m.balzer@nasa.govLocationNASA Goddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Astrophysics Dark Matter Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research The Universe Explore More
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By NASA
What does it take to gaze through time to our universe’s very first stars and galaxies?
NASA answers this question in its new documentary, “Cosmic Dawn: The Untold Story of the James Webb Space Telescope.” The agency’s original documentary, which chronicles the story of the most powerful telescope ever deployed in space, was released Wednesday, June 11.
Cosmic Dawn offers an unprecedented glimpse into the delicate assembly, rigorous testing, and triumphant launch of NASA’s James Webb Space Telescope. The documentary showcases the complexity involved in creating a telescope capable of peering billions of years into the past.
Cosmic Dawn is now available for streaming on NASA’s YouTube, NASA+, and select local theaters. The trailer is available on NASA+ and YouTube.
Relive the pitfalls and the triumphs of the world’s most powerful space telescope—from developing the idea of an impossible machine to watching with bated breath as it unfolded, hurtling through space a million miles away from Earth. Watch the Documentary on YouTube The film features never-before-seen footage captured by the Webb film crew, offering intimate access to the challenges and triumphs faced by the team at NASA’s Goddard Space Flight Center in Greenbelt, Maryland — the birthplace of Webb.
“At NASA, we’re thrilled to share the untold story of our James Webb Space Telescope in our new film ‘Cosmic Dawn,’ celebrating not just the discoveries, but the extraordinary people who made it all happen, for the benefit of humanity,” said Rebecca Sirmons, head of NASA+ at the agency’s headquarters in Washington.
From its vantage point more than a million miles from Earth and a massive sunshield to block the light of our star, Webb’s First Deep Field the deepest and sharpest infrared images of the universe that the world had seen.
Webb’s images have dazzled people around the globe, capturing the very faint light of the first stars and galaxies that formed more than 13.5 billion years ago. These are baby pictures from an ancient past when the first objects were turning on and emitting light after the Big Bang. Webb has also given us new insights into black holes, planets both inside and outside of our own solar system, and many other cosmic phenomena.
Webb was a mission that was going to be spectacular whether that was good or bad — if it failed or was successful. It was always going to make history
Sophia roberts
NASA Video Producer
NASA’s biggest and most powerful space telescope was also its most technically complicated to build. It was harder still to deploy, with more than 300 critical components that had to deploy perfectly. The risks were high in this complicated dance of engineering, but the rewards were so much higher.
“Webb was a mission that was going to be spectacular whether that was good or bad — if it failed or was successful,” said video producer Sophia Roberts, who chronicled the five years preceding Webb’s launch. “It was always going to make history.”
NASA scientists like Nobel Laureate Dr. John Mather conceived Webb to look farther and deeper into origins of our universe using cutting edge infrared technology and massive mirrors to collect incredibly rich information about our universe, from the light of the first galaxies to detailed images of planets in our own solar system.
To achieve this goal, NASA and its partners faced unprecedented hurdles.
Webb’s development introduced questions that no one had asked before. How do you fit a telescope with the footprint of a tennis court into a rocket? How do you clean 18 sensitive mirrors when a single scratch could render them inoperable? How do you maintain critical testing while hurricane stormwater pours through ceilings?
A technician inspects the James Webb Space Telescope primary mirrors at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.NASA/Sophia Roberts Cosmic Dawn captures 25 years of formidable design constraints, high-stake assessments, devastating natural disasters, a global pandemic and determined individuals who would let none of that get in the way of getting this monumental observatory to its rightful place in the cosmos.
“There was nothing easy about Webb at all,” said Webb project manager Bill Ochs. “I don’t care what aspect of the mission you looked at.”
Viewers will experience a one-of-a-kind journey as NASA and its partners tackle these dilemmas — and more — through ingenuity, teamwork, and unbreakable determination.
“The inspiration of trying to discover something — to build something that’s never been built before, to discover something that’s never been known before — it keeps us going,” Mather said. “We are pleased and privileged in our position here at NASA to be able to carry out this [purpose] on behalf of the country and the world.”
Bound by NASA’s 66-year commitment to document and share its work with the public, Cosmic Dawn details every step toward Webb’s launch and science results.
Learn more at nasa.gov/cosmicdawn By Laine Havens,
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media Contact:
Katie Konans,
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Jun 11, 2025 Related Terms
James Webb Space Telescope (JWST) Goddard Space Flight Center NASA+ View the full article
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