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By NASA
3 min read
NASA’s Cloud-based Confluence Software Helps Hydrologists Study Rivers on a Global Scale
The Paraná River in northern Argentina. Confluence, which is open-source and free to use, allows researchers to estimate river discharge and suspended sediment levels in Earth’s rivers at a global scale. NASA/ISS Rivers and streams wrap around Earth in complex networks millions of miles long, driving trade, nurturing ecosystems, and stocking critical reserves of freshwater.
But the hydrologists who dedicate their professional lives to studying this immense web of waterways do so with a relatively limited set of tools. Around the world, a patchwork of just 3,000 or so river gauge stations supply regular, reliable data, making it difficult for hydrologists to detect global trends.
“The best way to study a river,” said Colin Gleason, Armstrong Professional Development Professor of Civil and Environmental Engineering at the University of Massachusetts, Amherst, “is to get your feet wet and visit it yourself. The second best way to study a river is to use a river gauge.”
Now, thanks to Gleason and a team of more than 30 researchers, there’s another option: ‘Confluence,’ an analytic collaborative framework that leverages data from NASA’s Surface Water and Ocean Topography (SWOT) mission and the Harmonized Landsat Sentinel-2 archive (HLS) to estimate river discharge and suspended sediment levels in every river on Earth wider than 50 meters. NASA’s Physical Oceanography Distributed Active Archive Center (PO.DAAC) hosts the software, making it open-source and free for users around the world.
By incorporating both altimetry data from SWOT which informs discharge estimates, and optical data from HLS, which informs estimates of suspended sediment data, Confluence marks the first time hydrologists can create timely models of river size and water quality at a global scale. Compared to existing workflows for estimating suspended sediment using HLS data, Confluence is faster by a factor of 30.
I can’t do global satellite hydrology without this system. Or, I could, but it would be extremely time consuming and expensive.
Colin Gleason
Nikki Tebaldi, a Cloud Adoption Engineer at NASA’s Jet Propulsion Laboratory (JPL) and Co-Investigator for Confluence, was the lead developer on this project. She said that while the individual components of Confluence have been around for decades, bringing them together within a single, cloud-based processing pipeline was a significant challenge.
“I’m really proud that we’ve pieced together all of these different algorithms, got them into the cloud, and we have them all executing commands and working,” said Tebaldi.
Suresh Vannan, former manager of PO.DAAC and a Co-Investigator for Confluence, said this new ability to produce timely, global estimates of river discharge and quality will have a huge impact on hydrological models assessing everything from the health of river ecosystems to snowmelt.
“There are a bunch of science applications that river discharge can be used for, because it’s pretty much taking a snapshot of what the river looks like, how it behaves. Producing that snapshot on a global scale is a game changer,” said Vannan.
While the Confluence team is still working with PO.DAAC to complete their software package, users can currently access the Confluence source code here. For tutorials, manuals, and other user guides, visit the PO.DAAC webpage here.
All of these improvements to the original Confluence algorithms developed for SWOT were made possible by NASA’s Advanced Intelligent Systems Technology (AIST) program, a part of the agency’s Earth Science Technology Office (ESTO), in collaboration with SWOT and PO.DAAC.
To learn more about opportunities to develop next-generation technologies for studying Earth from outer space, visit ESTO’s solicitation page here.
Project Lead: Colin Gleason / University of Massachusetts, Amherst
Sponsoring Organization: Advanced Intelligent Systems Technology program, within NASA’s Earth Science Technology Office
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Last Updated Feb 04, 2025 Related Terms
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By NASA
Caption: Illustration of the four PUNCH spacecraft in low Earth orbit. Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab
NASA will hold a media teleconference at 2 p.m. EST on Tuesday, Feb. 4, to share information about the agency’s upcoming PUNCH (Polarimeter to Unify the Corona and Heliosphere) mission, which is targeted to launch no earlier than Thursday, Feb. 27.
The agency’s PUNCH mission is a constellation of four small satellites. When they arrive in low Earth orbit, the satellites will make global, 3D observations of the Sun’s outer atmosphere, the corona, and help NASA learn how the mass and energy there become solar wind. By imaging the Sun’s corona and the solar wind together, scientists hope to better understand the entire inner heliosphere – Sun, solar wind, and Earth – as a single connected system.
Audio of the teleconference will stream live on the agency’s website at:
https://www.nasa.gov/live
Participants include:
Madhulika Guhathakurta, NASA program scientist, NASA Headquarters Nicholeen Viall, PUNCH mission scientist, NASA’s Goddard Space Flight Center Craig DeForest, PUNCH principal investigator, Southwest Research Institute To participate in the media teleconference, media must RSVP no later than 12 p.m. on Feb. 4 to: Abbey Interrante at: abbey.a.interrante@nasa.gov. NASA’s media accreditation policy is available online.
The PUNCH mission will share a ride to space with NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) space telescope on a SpaceX Falcon 9 rocket from Space Launch Complex 4 East at Vandenberg Space Force Base in California.
The Southwest Research Institute in Boulder, Colorado, leads the PUNCH mission. The mission is managed by the Explorers Program Office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington.
To learn more about PUNCH, please visit:
https://nasa.gov/punch
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Karen Fox
Headquarters, Washington
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Sarah Frazier
Goddard Space Flight Center, Greenbelt, Md.
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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Typically, asteroids — like the one depicted in this artist’s concept — originate from the main asteroid belt between the orbits of Mars and Jupiter, but a small population of near-Earth objects may also come from the Moon’s surface after being ejected into space by an impact.NASA/JPL-Caltech The near-Earth object was likely ejected into space after an impact thousands of years ago. Now it could contribute new insights to asteroid and lunar science.
The small near-Earth object 2024 PT5 captured the world’s attention last year after a NASA-funded telescope discovered it lingering close to, but never orbiting, our planet for several months. The asteroid, which is about 33 feet (10 meters) wide, does not pose a hazard to Earth, but its orbit around the Sun closely matches that of our planet, hinting that it may have originated nearby.
As described in a study published Jan. 14 in the Astrophysical Journal Letters, researchers have collected further evidence of 2024 PT5 being of local origin: It appears to be composed of rock broken off from the Moon’s surface and ejected into space after a large impact.
“We had a general idea that this asteroid may have come from the Moon, but the smoking gun was when we found out that it was rich in silicate minerals — not the kind that are seen on asteroids but those that have been found in lunar rock samples,” said Teddy Kareta, an astronomer at Lowell Observatory in Arizona, who led the research. “It looks like it hasn’t been in space for very long, maybe just a few thousand years or so, as there’s a lack of space weathering that would have caused its spectrum to redden.”
The asteroid was first detected on Aug. 7, 2024, by the NASA-funded Sutherland, South Africa, telescope of the University of Hawai’i’s Asteroid Terrestrial-impact Last Alert System (ATLAS). Kareta’s team then used observations from the Lowell Discovery Telescope and the NASA Infrared Telescope Facility (IRTF) at the Mauna Kea Observatory in Hawai’i to show that the spectrum of reflected sunlight from the small object’s surface didn’t match that of any known asteroid type; instead, the reflected light more closely matched rock from the Moon.
Not (Old) Rocket Science
A second clue came from observing how the object moves. Along with asteroids, Space Age debris, such as old rockets from historic launches, can also be found in Earth-like orbits.
The difference in their orbits has to do with how each type responds to solar radiation pressure, which comes from the momentum of photons — quantum particles of light from the Sun — exerting a tiny force when they hit a solid object in space. This momentum exchange from many photons over time can push an object around ever so slightly, speeding it up or slowing it down. While a human-made object, like a hollow rocket booster, will move like an empty tin can in the wind, a natural object, such as an asteroid, will be much less affected.
Researchers studying asteroid 2024 PT5 have plotted its looping motion on two graphs. To a trained eye, they show that the object never gets captured by Earth’s gravity but, instead, lingers nearby before continuing its orbit around the Sun. NASA/JPL-Caltech To rule out 2024 PT5 being space junk, scientists at NASA’s Center for Near Earth Object Studies (CNEOS), which is managed by the agency’s Jet Propulsion Laboratory in Southern California, analyzed its motion. Their precise calculations of the object’s motion under the force of gravity ultimately enabled them to search for additional motion caused by solar radiation pressure. In this case, the effects were found to be too small for the object to be artificial, proving 2024 PT5 is most likely of natural origin.
“Space debris and space rocks move slightly differently in space,” said Oscar Fuentes-Muñoz, a study coauthor and NASA postdoctoral fellow at JPL working with the CNEOS team. “Human-made debris is usually relatively light and gets pushed around by the pressure of sunlight. That 2024 PT5 doesn’t move this way indicates it is much denser than space debris.”
Asteroid Lunar Studies
The discovery of 2024 PT5 doubles the number of known asteroids thought to originate from the Moon. Asteroid 469219 Kamo’oalewa was found in 2016 with an Earth-like orbit around the Sun, indicating that it may also have been ejected from the lunar surface after a large impact. As telescopes become more sensitive to smaller asteroids, more potential Moon boulders will be discovered, creating an exciting opportunity not only for scientists studying a rare population of asteroids, but also for scientists studying the Moon.
If a lunar asteroid can be directly linked to a specific impact crater on the Moon, studying it could lend insights into cratering processes on the pockmarked lunar surface. Also, material from deep below the lunar surface — in the form of asteroids passing close to Earth — may be accessible to future scientists to study.
“This is a story about the Moon as told by asteroid scientists,” said Kareta. “It’s a rare situation where we’ve gone out to study an asteroid but then strayed into new territory in terms of the questions we can ask of 2024 PT5.”
The ATLAS, IRTF, and CNEOS projects are funded by NASA’s planetary defense program, which is managed by the Planetary Defense Coordination Office at NASA Headquarters in Washington.
For more information about asteroids and comets, visit:
https://www.jpl.nasa.gov/topics/asteroids/
NASA Asteroid Experts Create Hypothetical Impact Scenario for Exercise NASA Researchers Discover More Dark Comets Lesson Plan: How to Explore an Asteroid News Media Contacts
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Last Updated Jan 22, 2025 Related Terms
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By NASA
This artist’s illustration represents the results from a new study that examines the effects of X-ray and other high-energy radiation unleashed on potential exoplanets from Wolf 359, a nearby red dwarf star. Researchers used Chandra and XMM-Newton to study the impact of steady X-ray and energetic ultraviolet radiation from Wolf 359 on the atmospheres of planets that might be orbiting the star. They found that only a planet with greenhouse gases like carbon dioxide in its atmosphere and at a relatively large distance away from Wolf 359 would have a chance to support life as we know it.X-ray: NASA/CXC/SAO/S.Wolk, et al.; Illustration: NASA/CXC/SAO/M.Weiss; Image processing: NASA/CXC/SAO/N. Wolk Planets around other stars need to be prepared for extreme weather conditions, according to a new study from NASA’s Chandra X-ray Observatory and ESA’s (European Space Agency’s) XMM-Newton that examined the effects of X-rays on potential planets around the most common type of stars.
Astronomers found that only a planet with greenhouse gases in its atmosphere like Earth and at a relatively large distance away from the star they studied would have a chance to support life as we know it around a nearby star.
Wolf 359 is a red dwarf with a mass about a tenth that of the Sun. Red dwarf stars are the most common stars in the universe and live for billions of years, providing ample time for life to develop. At a distance of only 7.8 light-years away, Wolf 359 is also one of the closest stars to the solar system.
“Wolf 359 can help us unlock the secrets around stars and habitability,” said Scott Wolk of the Center for Astrophysics | Harvard & Smithsonian (CfA), who led the study. “It’s so close and it belongs to such an important class of stars – it’s a great combination.”
Because red dwarfs are the most prevalent types of stars, astronomers have looked hard to find exoplanets around them. Astronomers have found some evidence for two planets in orbit around Wolf 359 using optical telescopes, but those conclusions have been challenged by other scientists.
“While we don’t have proof of planets around Wolf 359 yet, it seems very possible that it hosts multiple planets,” Wolk added. “This makes it an excellent test bed to look at what planets would experience around this kind of star.”
Wolk and his colleagues used Chandra and XMM to study the amounts of steady X-rays and extreme ultraviolet (UV) radiation – the most energetic type of UV radiation – that Wolf 359 would unleash on the possible planets around it.
They found that Wolf 359 is producing enough damaging radiation that only a planet with greenhouse gases like carbon dioxide in its atmosphere – and located at a relatively large distance from the star – would likely be able to sustain life.
“Just being far enough away from the star’s harmful radiation wouldn’t be enough to make it habitable,” said co-author Vinay Kashyap, also of CfA. “A planet around Wolf 359 would also need to be blanketed in greenhouse gases like Earth is.”
To study the effects of energetic radiation on the habitability of the planet candidates, the team considered the star’s habitable zone – the region around a star where liquid water could exist on a planet’s surface.
The outer limit of the habitable zone for Wolf 359 is about 15% of the distance between Earth and the Sun, because the red dwarf is much less bright than the Sun. Neither of the planet candidates for this system is located in Wolf 359’s habitable zone, with one too close to the star and the other too far out.
“If the inner planet is there, the X-ray and extreme UV radiation it is subjected to would destroy the atmosphere of this planet in only about a million years,” said co-author Ignazio Pillitteri of CfA and the National Institute for Astrophysics in Palermo, Italy.
The team also considered the effects of radiation on as-yet undetected planets within the habitable zone. They concluded that a planet like the Earth in the middle of the habitable zone should be able to sustain an atmosphere for almost two billion years, while one near the outer edge could last indefinitely, helped by the warming effects of greenhouse gases.
Another big danger for planets orbiting stars like Wolf 359 is from X-ray flares, or occasional bright bursts of X-rays, on top of the steady, everyday output from the star. Combining observations made with Chandra and XMM-Newton resulted in the discovery of 18 X-ray flares from Wolf 359 over 3.5 days.
Extrapolating from these observed flares, the team expects that much more powerful and damaging flares would occur over longer periods of time. The combined effects of the steady X-ray and UV radiation and the flares mean that any planet located in the habitable zone is unlikely to have a significant atmosphere long enough for multicellular life, as we know it on Earth, to form and survive. The exception is the habitable zone’s outer edge if the planet has a significant greenhouse effect.
These results were presented at the 245th meeting of the American Astronomical Society in National Harbor, Maryland, and are being prepared for publication in a journal. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
Read more from NASA’s Chandra X-ray Observatory.
Learn more about the Chandra X-ray Observatory and its mission here:
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By NASA
Webb Webb News Latest News Latest Images Blog (offsite) Awards X (offsite – login reqd) Instagram (offsite – login reqd) Facebook (offsite- login reqd) Youtube (offsite) Overview About Who is James Webb? Fact Sheet Impacts+Benefits FAQ Science Overview and Goals Early Universe Galaxies Over Time Star Lifecycle Other Worlds Observatory Overview Launch Orbit Mirrors Sunshield Instrument: NIRCam Instrument: MIRI Instrument: NIRSpec Instrument: FGS/NIRISS Optical Telescope Element Backplane Spacecraft Bus Instrument Module Multimedia About Webb Images Images Videos What is Webb Observing? 3d Webb in 3d Solar System Podcasts Webb Image Sonifications Team International Team People Of Webb More For the Media For Scientists For Educators For Fun/Learning 6 Min Read Newfound Galaxy Class May Indicate Early Black Hole Growth, Webb Finds
A team of astronomers sifted through James Webb Space Telescope data from multiple surveys to compile one of the largest samples of “little red dots” to date. Credits:
NASA, ESA, CSA, STScI, Dale Kocevski (Colby College). In December 2022, less than six months after commencing science operations, NASA’s James Webb Space Telescope revealed something never seen before: numerous red objects that appear small on the sky, which scientists soon called “little red dots” (LRDs). Though these dots are quite abundant, researchers are perplexed by their nature, the reason for their unique colors, and what they convey about the early universe.
A team of astronomers recently compiled one of the largest samples of LRDs to date, nearly all of which existed during the first 1.5 billion years after the big bang. They found that a large fraction of the LRDs in their sample showed signs of containing growing supermassive black holes.
“We’re confounded by this new population of objects that Webb has found. We don’t see analogs of them at lower redshifts, which is why we haven’t seen them prior to Webb,” said Dale Kocevski of Colby College in Waterville, Maine, and lead author of the study. “There’s a substantial amount of work being done to try to determine the nature of these little red dots and whether their light is dominated by accreting black holes.”
Image A: Little Red Dots (NIRCam Image)
A team of astronomers sifted through James Webb Space Telescope data from multiple surveys to compile one of the largest samples of “little red dots” to date. From their sample, they found that these mysterious red objects that appear small on the sky emerge in large numbers around 600 million years after the big bang and undergo a rapid decline in quantity around 1.5 billion years after the big bang. NASA, ESA, CSA, STScI, Dale Kocevski (Colby College). A Potential Peek Into Early Black Hole Growth
A significant contributing factor to the team’s large sample size of LRDs was their use of publicly available Webb data. To start, the team searched for these red sources in the Cosmic Evolution Early Release Science (CEERS) survey before widening their scope to other extragalactic legacy fields, including the JWST Advanced Deep Extragalactic Survey (JADES) and the Next Generation Deep Extragalactic Exploratory Public (NGDEEP) survey.
The methodology used to identify these objects also differed from previous studies, resulting in the census spanning a wide redshift range. The distribution they discovered is intriguing: LRDs emerge in large numbers around 600 million years after the big bang and undergo a rapid decline in quantity around 1.5 billion years after the big bang.
The team looked toward the Red Unknowns: Bright Infrared Extragalactic Survey (RUBIES) for spectroscopic data on some of the LRDs in their sample. They found that about 70 percent of the targets showed evidence for gas rapidly orbiting 2 million miles per hour (1,000 kilometers per second) – a sign of an accretion disk around a supermassive black hole. This suggests that many LRDs are accreting black holes, also known as active galactic nuclei (AGN).
“The most exciting thing for me is the redshift distributions. These really red, high-redshift sources basically stop existing at a certain point after the big bang,” said Steven Finkelstein, a co-author of the study at the University of Texas at Austin. “If they are growing black holes, and we think at least 70 percent of them are, this hints at an era of obscured black hole growth in the early universe.”
Contrary to Headlines, Cosmology Isn’t Broken
When LRDs were first discovered, some suggested that cosmology was “broken.” If all of the light coming from these objects was from stars, it implied that some galaxies had grown so big, so fast, that theories could not account for them.
The team’s research supports the argument that much of the light coming from these objects is from accreting black holes and not from stars. Fewer stars means smaller, more lightweight galaxies that can be understood by existing theories.
“This is how you solve the universe-breaking problem,” said Anthony Taylor, a co-author of the study at the University of Texas at Austin.
Curiouser and Curiouser
There is still a lot up for debate as LRDs seem to evoke even more questions. For example, it is still an open question as to why LRDs do not appear at lower redshifts. One possible answer is inside-out growth: As star formation within a galaxy expands outward from the nucleus, less gas is being deposited by supernovas near the accreting black hole, and it becomes less obscured. In this case, the black hole sheds its gas cocoon, becomes bluer and less red, and loses its LRD status.
Additionally, LRDs are not bright in X-ray light, which contrasts with most black holes at lower redshifts. However, astronomers know that at certain gas densities, X-ray photons can become trapped, reducing the amount of X-ray emission. Therefore, this quality of LRDs could support the theory that these are heavily obscured black holes.
The team is taking multiple approaches to understand the nature of LRDs, including examining the mid-infrared properties of their sample, and looking broadly for accreting black holes to see how many fit LRD criteria. Obtaining deeper spectroscopy and select follow-up observations will also be beneficial for solving this currently “open case” about LRDs.
“There’s always two or more potential ways to explain the confounding properties of little red dots,” said Kocevski. “It’s a continuous exchange between models and observations, finding a balance between what aligns well between the two and what conflicts.”
These results were presented in a press conference at the 245th meeting of the American Astronomical Society in National Harbor, Maryland, and have been submitted for publication in The Astrophysical Journal.
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).
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Laura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Abigail Major – amajor@stsci.edu, Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Science – Dale Kocevski (Colby College)
Related Information
3D visualization: CEERS Fly Through visualization and JADES GOODS South Fly Through visualization
Graphic: What is cosmological redshift?
Graphic: Dissecting Supermassive Black Holes
Article: Webb Science: Galaxies Through Time
Web Page: Learn more about black holes
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Last Updated Jan 14, 2025 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
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