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By NASA
Tiny satellites, also known as CubeSats, are pictured after being deployed into Earth orbit from a small satellite orbital deployer on the outside of the International Space Station’s Kibo laboratory module. The CubeSats were delivered aboard the Northrop Grumman Cygnus space freighter and will serve a variety of educational and research purposes for public and private organizations around the world.
Image Credit: NASA/Tracy Dyson
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By European Space Agency
In 2022 NASA’s DART spacecraft made history, and changed the Solar System forever, by impacting the Dimorphos asteroid and measurably shifting its orbit around the larger Didymos asteroid. In the process a plume of debris was thrown out into space.
The latest modelling, available on the preprint server arXiv and accepted for publication in the September volume of The Planetary Science Journal, shows how small meteoroids from that debris could eventually reach both Mars and Earth – potentially in an observable (although quite safe) manner.
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By European Space Agency
The two new Galileo satellites launched in April have entered service, completing the second of three constellation planes. With every addition to the constellation, the precision, availability and robustness of the Galileo signal is improved. The next launch is planned in the coming weeks and the remaining six Galileo First Generation satellites will join the constellation in the next years.
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By NASA
5 Min Read Webb Finds Early Galaxies Weren’t Too Big for Their Britches After All
This image shows a small portion of the field observed by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) for the Cosmic Evolution Early Release Science (CEERS) survey. The full image appears below. Credits:
NASA, ESA, CSA, S. Finkelstein (University of Texas) It got called the crisis in cosmology. But now astronomers can explain some surprising recent discoveries.
When astronomers got their first glimpses of galaxies in the early universe from NASA’s James Webb Space Telescope, they were expecting to find galactic pipsqueaks, but instead they found what appeared to be a bevy of Olympic bodybuilders. Some galaxies appeared to have grown so massive, so quickly, that simulations couldn’t account for them. Some researchers suggested this meant that something might be wrong with the theory that explains what the universe is made of and how it has evolved since the big bang, known as the standard model of cosmology.
According to a new study in the Astrophysical Journal led by University of Texas at Austin graduate student Katherine Chworowsky, some of those early galaxies are in fact much less massive than they first appeared. Black holes in some of these galaxies make them appear much brighter and bigger than they really are.
“We are still seeing more galaxies than predicted, although none of them are so massive that they ‘break’ the universe,” Chworowsky said.
The evidence was provided by Webb’s Cosmic Evolution Early Release Science (CEERS) Survey, led by Steven Finkelstein, a professor of astronomy at UT Austin and study co-author.
Image A : CEERS Deep Field (NIRCam)
This image shows a small portion of the field observed by NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) for the Cosmic Evolution Early Release Science (CEERS) survey. It is filled with galaxies. Some galaxies appear to have grown so massive, so quickly, that simulations couldn’t account for them. However, a new study finds that some of those early galaxies are in fact much less massive than they first appeared. Black holes in some of those galaxies make them appear much brighter and bigger than they really are. NASA, ESA, CSA, S. Finkelstein (University of Texas)
View 8k pixel full resolution version of the image
Black Holes Add to Brightness
According to this latest study, the galaxies that appeared overly massive likely host black holes rapidly consuming gas. Friction in the fast-moving gas emits heat and light, making these galaxies much brighter than they would be if that light emanated just from stars. This extra light can make it appear that the galaxies contain many more stars, and hence are more massive, than we would otherwise estimate. When scientists remove these galaxies, dubbed “little red dots” (based on their red color and small size), from the analysis, the remaining early galaxies are not too massive to fit within predictions of the standard model.
“So, the bottom line is there is no crisis in terms of the standard model of cosmology,” Finkelstein said. “Any time you have a theory that has stood the test of time for so long, you have to have overwhelming evidence to really throw it out. And that’s simply not the case.”
Efficient Star Factories
Although they’ve settled the main dilemma, a less thorny problem remains: There are still roughly twice as many massive galaxies in Webb’s data of the early universe than expected from the standard model. One possible reason might be that stars formed more quickly in the early universe than they do today.
“Maybe in the early universe, galaxies were better at turning gas into stars,” Chworowsky said.
Star formation happens when hot gas cools enough to succumb to gravity and condense into one or more stars. But as the gas contracts, it heats up, generating outward pressure. In our region of the universe, the balance of these opposing forces tends to make the star formation process very slow. But perhaps, according to some theories, because the early universe was denser than today, it was harder to blow gas out during star formation, allowing the process to go faster.
More Evidence of Black Holes
Concurrently, astronomers have been analyzing the spectra of “little red dots” discovered with Webb, with researchers in both the CEERS team and others finding evidence of fast-moving hydrogen gas, a signature of black hole accretion disks. This supports the idea that at least some of the light coming from these compact, red objects comes from gas swirling around black holes, rather than stars – reinforcing Chworowsky and their team’s conclusion that they are probably not as massive as astronomers initially thought. However, further observations of these intriguing objects are incoming, and should help solve the puzzle about how much light comes from stars versus gas around black holes.
Often in science, when you answer one question, that leads to new questions. While Chworowsky and their colleagues have shown that the standard model of cosmology likely isn’t broken, their work points to the need for new ideas in star formation.
“And so there is still that sense of intrigue,” Chworowsky said. “Not everything is fully understood. That’s what makes doing this kind of science fun, because it’d be a terribly boring field if one paper figured everything out, or there were no more questions to answer.”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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Media Contacts
Laura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Marc Airhart – mairhart@austin.utexas.edu
University of Texas at Austin
Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Related Information
VIDEO: CEERS Fly-through data visualization
ARTICLE: Webb Science – Galaxies Through Time
INFOGRAPHIC: Learn More about black holes
VIDEO: Webb Science Snippets Video: “The Early Universe”
INFOGRAPHIC: What is Cosmological Redshift?
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Webb Mission Page
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Last Updated Aug 26, 2024 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
Astrophysics Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research Goddard Space Flight Center James Webb Space Telescope (JWST) Science & Research The Universe View the full article
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By NASA
2 min read
NASA’s DART Team Earns AIAA Space Systems Award for Pioneering Mission
NASA’s DART (Double Asteroid Redirection Test) mission continues to yield scientific discoveries and garner accolades for its groundbreaking achievements. The mission team was recently recognized by the American Institute of Aeronautics and Astronautics (AIAA)with the 2024 Space Systems Award during this year’s AIAA ASCEND event, held July 29 to Aug. 2 in Las Vegas.
APL’s Geffrey Ottman (left), electrical systems engineer on NASA’s DART (Double Asteroid Redirection Test) and APL’s Betsy Congdon (center), who served as the mechanical systems engineer on the mission, accepted the 2024 American Institute of Aeronautics and Astronautics (AIAA) Space Systems Award on behalf of the team during this year’s AIAA ASCEND event, which was held from July 29 to Aug. 2 in Las Vegas, Nevada. Credit: AIAA The award, presented by the AIAA Space Systems Technical Committee, celebrates outstanding achievements in the architecture, analysis, design and implementation of space systems. The DART team was lauded for “outstanding achievement in the development and operation of the DART spacecraft, completing humanity’s first in-space demonstration of planetary defense technology.”
Designed, built and operated for NASA by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, the DART spacecraft was launched in 2021 and, roughly 10 months later, successfully impacted the asteroid Dimorphos in the fall of 2022. The deliberate collision altered the asteroid’s orbit around its larger companion asteroid, Didymos, by 33 minutes. That historic achievement showcased the potential to divert hazardous asteroids, offering a critical tool for safeguarding Earth from real possible impacts in the future.
The Space Systems Award has regularly recognized extraordinary achievements in space system design and implementation. The DART mission joins a distinguished list of past recipients who have significantly advanced the field of aerospace science and technology.
APL managed the DART mission for NASA’s Planetary Defense Coordination Office as a project of the agency’s Planetary Missions Program Office. NASA provided support for the mission from several centers, including the Jet Propulsion Laboratory in Southern California; Goddard Space Flight Center in Greenbelt, Maryland; Johnson Space Center in Houston; Glenn Research Center in Cleveland; and Langley Research Center in Hampton, Virginia.
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Last Updated Aug 21, 2024 Editor Bill Keeter Related Terms
DART (Double Asteroid Redirection Test) Planetary Defense Coordination Office View the full article
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