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By Space Force
Over the past two years, the first U.S. space service component has tripled in size, established a 24/7 space watch cell and executed three Tier 1 Combatant Command exercises.
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By NASA
NASA/JPL-Caltech This Oct. 4, 2017, illustration shows a hypothetical uneven ring of dust orbiting KIC 8462852, also known as Boyajian’s Star or Tabby’s Star. The star has experienced unusual dips in brightness over a matter of days, as well as much subtler but longer-term dimming trends. Scientists proposed several explanations for this unexpected behavior, ranging from Tabby’s Star swallowing a planet to alien “megastructures” harvesting the star’s energy. However, a study using NASA’s Spitzer and Swift missions as well as the Belgian AstroLAB IRIS observatory suggests that the cause of the dimming over long periods is likely an uneven dust cloud moving around the star.
Learn more about this enigmatic star, named after Tabetha Boyajian, the Yale University postdoc who discovered it with the help of citizen scientists.
Image credit: NASA/JPL-Caltech
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By NASA
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
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A 3D simulation showing the evolution of turbulent flows in the upper layers of the Sun. The more saturated and bright reds represent the most vigorous upward or downward twisting motions. Clear areas represent areas where there is only relatively slow up-flows, with very little twisting.NASA/Irina Kitiashvili and Timothy A. Sandstrom NASA supercomputers are shedding light on what causes some of the Sun’s most complex behaviors. Using data from the suite of active Sun-watching spacecraft currently observing the star at the heart of our solar system, researchers can explore solar dynamics like never before.
The animation shows the strength of the turbulent motions of the Sun’s inner layers as materials twist into its atmosphere, resembling a roiling pot of boiling water or a flurry of schooling fish sending material bubbling up to the surface or diving it further down below.
“Our simulations use what we call a realistic approach, which means we include as much as we know to-date about solar plasma to reproduce different phenomena observed with NASA space missions,” said Irina Kitiashvili, a scientist at NASA’s Ames Research Center in California’s Silicon Valley who helped lead the study.
Using modern computational capabilities, the team was able, for the first time to reproduce the fine structures of the subsurface layer observed with NASA’s Solar Dynamics Observatory.
“Right now, we don’t have the computational capabilities to create realistic global models of the entire Sun due to the complexity,” said Kitiashvili. “Therefore, we create models of smaller areas or layers, which can show us structures of the solar surface and atmosphere – like shock waves or tornado-like features measuring only a few miles in size; that’s much finer detail than any one spacecraft can resolve.”
Scientists seek to better understand the Sun and what phenomena drive the patterns of its activity. The connection and interactions between the Sun and Earth drive the seasons, ocean currents, weather, climate, radiation belts, auroras and many other phenomena. Space weather predictions are critical for exploration of space, supporting the spacecraft and astronauts of NASA’s Artemis campaign. Surveying this space environment is a vital part of understanding and mitigating astronaut exposure to space radiation and keeping our spacecraft and instruments safe.
This has been a big year for our special star, studded with events like the annular eclipse, a total eclipse, and the Sun reaching its solar maximum period. In December 2024, NASA’s Parker Solar Probe mission – which is helping researchers to understand space weather right at the source – will make its closest-ever approach to the Sun and beat its own record of being the closest human-made object to reach the Sun.
The Sun keeps surprising us. We are looking forward to seeing what kind of exciting events will be organized by the Sun."
Irina Kitiashvili
NASA Scientist
“The Sun keeps surprising us,” said Kitiashvili. “We are looking forward to seeing what kind of exciting events will be organized by the Sun.”
These simulations were run on the Pleaides supercomputer at the NASA Advanced Supercomputing facility at NASA Ames over several weeks of runtime, generating terabytes of data.
NASA is showcasing 29 of the agency’s computational achievements at SC24, the international supercomputing conference, Nov. 17-22, 2023, in Atlanta, Georgia. For more technical information, visit:
https://www.nas.nasa.gov/sc24
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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Last Updated Nov 21, 2024 Related Terms
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Parker Solar Probe
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By NASA
Hubble Space Telescope Home NASA’s Hubble Finds… Hubble Space Telescope Hubble Home Overview About Hubble The History of Hubble Hubble Timeline Why Have a Telescope in Space? Hubble by the Numbers At the Museum FAQs Impact & Benefits Hubble’s Impact & Benefits Science Impacts Cultural Impact Technology Benefits Impact on Human Spaceflight Astro Community Impacts Science Hubble Science Science Themes Science Highlights Science Behind Discoveries Hubble’s Partners in Science Universe Uncovered Explore the Night Sky Observatory Hubble Observatory Hubble Design Mission Operations Missions to Hubble Hubble vs Webb Team Hubble Team Career Aspirations Hubble Astronauts News Hubble News Hubble News Archive Social Media Media Resources Multimedia Multimedia Images Videos Sonifications Podcasts E-books Lithographs Fact Sheets Glossary Posters Hubble on the NASA App More Online Activities 5 Min Read NASA’s Hubble Finds Sizzling Details About Young Star FU Orionis
An artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. Credits:
NASA-JPL, Caltech In 1936, astronomers saw a puzzling event in the constellation Orion: the young star FU Orionis (FU Ori) became a hundred times brighter in a matter of months. At its peak, FU Ori was intrinsically 100 times brighter than our Sun. Unlike an exploding star though, it has declined in luminosity only languidly since then.
Now, a team of astronomers has wielded NASA’s Hubble Space Telescope‘s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. They find that the inner disk touching the star is extraordinarily hot — which challenges conventional wisdom.
The observations were made with the telescope’s COS (Cosmic Origins Spectrograph) and STIS (Space Telescope Imaging Spectrograph) instruments. The data includes the first far-ultraviolet and new near-ultraviolet spectra of FU Ori.
“We were hoping to validate the hottest part of the accretion disk model, to determine its maximum temperature, by measuring closer to the inner edge of the accretion disk than ever before,” said Lynne Hillenbrand of Caltech in Pasadena, California, and a co-author of the paper. “I think there was some hope that we would see something extra, like the interface between the star and its disk, but we were certainly not expecting it. The fact we saw so much extra — it was much brighter in the ultraviolet than we predicted — that was the big surprise.”
A Better Understanding of Stellar Accretion
Originally deemed to be a unique case among stars, FU Ori exemplifies a class of young, eruptive stars that undergo dramatic changes in brightness. These objects are a subset of classical T Tauri stars, which are newly forming stars that are building up by accreting material from their disk and the surrounding nebula. In classical T Tauri stars, the disk does not touch the star directly because it is restricted by the outward pressure of the star’s magnetic field.
The accretion disks around FU Ori objects, however, are susceptible to instabilities due to their enormous mass relative to the central star, interactions with a binary companion, or infalling material. Such instability means the mass accretion rate can change dramatically. The increased pace disrupts the delicate balance between the stellar magnetic field and the inner edge of the disk, leading to material moving closer in and eventually touching the star’s surface.
This is an artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. A team of astronomers has used the Hubble Space Telescope’s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. They found that the inner disk, touching the star, is much hotter than expected—16,000 kelvins—nearly three times our Sun’s surface temperature. That sizzling temperature is nearly twice as hot as previously believed. NASA-JPL, Caltech
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The enhanced infall rate and proximity of the accretion disk to the star make FU Ori objects much brighter than a typical T Tauri star. In fact, during an outburst, the star itself is outshined by the disk. Furthermore, the disk material is orbiting rapidly as it approaches the star, much faster than the rotation rate of the stellar surface. This means that there should be a region where the disk impacts the star and the material slows down and heats up significantly.
“The Hubble data indicates a much hotter impact region than models have previously predicted,” said Adolfo Carvalho of Caltech and lead author of the study. “In FU Ori, the temperature is 16,000 kelvins [nearly three times our Sun’s surface temperature]. That sizzling temperature is almost twice the amount prior models have calculated. It challenges and encourages us to think of how such a jump in temperature can be explained.”
To address the significant difference in temperature between past models and the recent Hubble observations, the team offers a revised interpretation of the geometry within FU Ori’s inner region: The accretion disk’s material approaches the star and once it reaches the stellar surface, a hot shock is produced, which emits a lot of ultraviolet light.
Planet Survival Around FU Ori
Understanding the mechanisms of FU Ori’s rapid accretion process relates more broadly to ideas of planet formation and survival.
“Our revised model based on the Hubble data is not strictly bad news for planet evolution, it’s sort of a mixed bag,” explained Carvalho. “If the planet is far out in the disk as it’s forming, outbursts from an FU Ori object should influence what kind of chemicals the planet will ultimately inherit. But if a forming planet is very close to the star, then it’s a slightly different story. Within a couple outbursts, any planets that are forming very close to the star can rapidly move inward and eventually merge with it. You could lose, or at least completely fry, rocky planets forming close to such a star.”
Additional work with the Hubble UV observations is in progress. The team is carefully analyzing the various spectral emission lines from multiple elements present in the COS spectrum. This should provide further clues on FU Ori’s environment, such as the kinematics of inflowing and outflowing gas within the inner region.
“A lot of these young stars are spectroscopically very rich at far ultraviolet wavelengths,” reflected Hillenbrand. “A combination of Hubble, its size and wavelength coverage, as well as FU Ori’s fortunate circumstances, let us see further down into the engine of this fascinating star-type than ever before.”
These findings have been published in The Astrophysical Journal Letters.
The observations were taken as part of General Observer program 17176.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contacts:
Claire Andreoli (claire.andreoli@nasa.gov)
NASA’s Goddard Space Flight Center, Greenbelt, MD
Abigail Major, Ray Villard
Space Telescope Science Institute, Baltimore, MD
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Last Updated Nov 21, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
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Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Exploring the Birth of Stars
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Hubble Focus: The Lives of Stars
This e-book highlights the mission’s recent discoveries and observations related to the birth, evolution, and death of stars.
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By NASA
On Nov. 16, 2009, space shuttle Atlantis began its 31st trip into space, on the third Utilization and Logistics Flight (ULF3) mission to the International Space Station, the 31st shuttle flight to the orbiting lab. During the 11-day mission, the six-member STS-129 crew worked with the six-person Expedition 21 crew during seven days of docked operations. The mission’s primary objectives included delivering two external logistics carriers and their spare parts, adding nearly 15 tons of hardware to the station, and returning a long-duration crew member, the last to return on a shuttle. Three of the STS-129 astronauts conducted three spacewalks to transfer spare parts and continue assembly and maintenance of the station. As a group of 12, the joint crews celebrated the largest and most diverse Thanksgiving gathering in space.
Left: Official photograph of the STS-129 crew of Leland D. Melvin, left, Charles O. Hobaugh, Michael J. Foreman, Robert “Bobby” L. Satcher, Barry “Butch” E. Wilmore, and Randolph “Randy” J. Bresnik. Middle: The STS-129 crew patch. Right: The ULF3 payload patch.
The six-person STS-129 crew consisted of Commander Charles O. Hobaugh, Pilot Barry “Butch” E. Wilmore, and Mission Specialists Randolph “Randy” J. Bresnik, Michael J. Foreman, Leland D. Melvin, and Robert “Bobby” L. Satcher. Primary objectives of the mission included launch and transfer to the station of the first two EXPRESS Logistics Carriers (ELC-1 and ELC-2) and their multiple spare parts, and the return of NASA astronaut and Expedition 20 and 21 Flight Engineer Nicole P. Stott, the last astronaut to rotate on the shuttle.
Left: In the Orbiter Processing Facility (OPF) at NASA’s Kennedy Space Center in Florida, workers finish processing Atlantis for STS-129. Right: Space shuttle Atlantis rolls over from the OPF to the Vehicle Assembly Building.
Left: Atlantis rolls out to Launch Pad 39A. Right: The STS-129 crew during the Terminal Countdown Demonstration Test.
Atlantis returned to NASA’s Kennedy Space Center (KSC) from its previous mission, STS-125, on June 2, 2009, and workers towed it to the Orbiter Processing Facility (OPF) to prepare it for STS-129. The orbiter rolled over to the Vehicle Assembly Building on Oct. 6, and after mating with its external tank and twin solid rocket boosters, rolled out to Launch Pad 39A on Oct. 14, targeting a Nov. 16 launch. Six days later, the six-member crew participated in the Terminal Countdown Demonstration Test, essentially a dress rehearsal of the actual countdown for launch, returning to Houston for final training. They returned to KSC on Nov. 13 to prepare for launch.
Left: With Atlantis sitting on Launch Pad 39A, the Ares 1-X rocket lifts off from Launch Pad 39B. Right: The payload canister arrives at Launch Pad 39A.
Left: The STS-129 astronauts leave crew quarters for the ride to Launch Pad 39A. Right: Liftoff of space shuttle Atlantis on STS-129.
On Nov. 16, at 2:28 p.m. EST, space shuttle Atlantis lifted off from Launch Pad 39A to begin its 31st trip into space, carrying its six-member crew on the ULF3 space station outfitting and resupply mission. Eight and a half minutes later, Atlantis and its crew had reached orbit. The flight marked Hobaugh’s third time in space, having flown on STS-104 and STS-118, Foreman’s and Melvin’s second, having flown on STS-123 and STS-122, respectively, while Wilmore, Bresnik, and Satcher enjoyed their first taste of weightlessness.
Left: The two EXPRESS Logistics Carriers in Atlantis’ payload bay. Middle: Leland D. Melvin participates in the inspection of Atlantis’ thermal protection system. Right: The Shuttle Remote Manipulator System grasps the Orbiter Boom Sensor System for the inspection.
After reaching orbit, the crew opened the payload bay doors, deployed the shuttle’s radiators, and removed their bulky launch and entry suits, stowing them for the remainder of the flight. The astronauts spent six hours on their second day in space conducting a detailed inspection of Atlantis’ nose cap and wing leading edges, with Hobaugh, Wilmore, Melvin, and Bresnik taking turns operating the Shuttle Remote Manipulator System (SRMS), or robotic arm, and the Orbiter Boom Sensor System (OBSS).
Left: The International Space Station as seen from Atlantis during the rendezvous and docking maneuver. Middle: Atlantis as seen from the space station, showing the two EXPRESS Logistics Carriers (ELC) in the payload bay. Right: View of the space station from Atlantis during the rendezvous pitch maneuver, with the Shuttle Remote Manipulator System grasping ELC-1 in preparation for transfer shortly after docking.
On the mission’s third day, Hobaugh assisted by his crewmates brought Atlantis in for a docking with the space station. During the rendezvous, Hobaugh stopped the approach at 600 feet and completed the Rendezvous Pitch Maneuver so astronauts aboard the station could photograph Atlantis’ underside to look for any damage to the tiles. Shortly after docking, the crews opened the hatches between the two spacecraft and the six-person station crew welcomed the six-member shuttle crew. After the welcoming ceremony, Stott joined the STS-129 crew, leaving a crew of five aboard the station. Melvin and Bresnik used the SRMS to pick up ELC-1 from the payload bay and hand it off to Wilmore and Expedition 21 NASA astronaut Jeffrey N. Williams operating the Space Station Remote Manipulator System (SSRMS), who then installed it on the P3 truss segment.
Images from the first spacewalk. Left: Michael J. Foreman unstows the S-band Antenna Support Assembly prior to transferring it to the station. Middle: Robert “Bobby” L. Satcher lubricates the robotic arm’s Latching End Effector. Right: Satcher’s image reflected in a Z1 radiator panel.
During the mission’s first of three spacewalks on flight day four, Foreman and Satcher ventured outside for six hours and 37 minutes. During the excursion, with robotic help from their fellow crew members, they transferred a spare S-band Antenna Support Assembly from the shuttle’s payload bay to the station’s Z1 truss. Satcher, an orthopedic surgeon by training, performed “surgery” on the station’s main robotic arm as well as the robotic arm on the Kibo Japanese module, by lubricating their latching end effectors. One day after joining Atlantis’ crew, Stott celebrated her 47th birthday.
Left: Space station crew member Jeffery N. Williams assists STS-129 astronaut Leland D. Melvin in operating the space station’s robotic arm to transfer and install the second EXPRESS Logistics Carrier (ELC2) on the S3 truss. Middle: The station robotic arm installs ELC2 on the S3 truss. Right: Michael J. Foreman, left, and Randolph J. Bresnik during the mission’s second spacewalk.
On the mission’s fifth day, the astronauts performed another focused inspection of the shuttle’s thermal protection system. The next day, through another coordinated robotic activity involving the shuttle and station arms, the astronauts transferred ELC-2 and its complement of spares from the payload bay to the station’s S3 truss. Foreman and Bresnik completed the mission’s second spacewalk. Working on the Columbus module, they installed the Grappling Adaptor to On-Orbit Railing (GATOR) fixture that includes a system used for ship identification and an antenna for Ham radio operators. They next installed a wireless video transmission system on the station’s truss. This spacewalk lasted six hours and eight minutes.
Left: Randolph J. Bresnik during the third STS-129 spacewalk. Middle: Robert “Bobby” L. Satcher during the third spacewalk. Right: The MISSE 7 exposure experiment suitcases installed on ELC2.
Following a crew off duty day, on flight day eight Satcher and Bresnik exited the airlock for the mission’s third and final spacewalk. Their first task involved moving an oxygen tank from the newly installed ELC-2 to the Quest airlock. They accomplished this task with robotic assistance from their fellow crew members. Bresnik retrieved the two-suitcase sized MISSE-7 experiment containers from the shuttle cargo bay and installed them on the MISSE-7 platform on ELC-2, opening them to begin their exposure time. This third spacewalk lasted five hours 42 minutes.
Left: An early Thanksgiving meal for 12 aboard the space station. Right: After the meal, who has the dishes?
Thanksgiving Day fell on the day after undocking, so the joint crews celebrated with a meal a few days early. The meal represented not only the largest Thanksgiving celebration in space with 12 participants, but also the most international, with four nations represented – the United States, Russia, Canada, and Belgium (representing the European Space Agency).
Left: The 12 members of Expedition 21 and STS-129 pose for a final photograph before saying their farewells. Right: The STS-129 crew, now comprising seven members.
A selection of STS-129 Earth observation images. Left: Maui. Middle: Los Angeles. Right: Houston.
Despite their busy workload, as with all space crews, the STS-129 astronauts made time to look out the windows and took hundreds of photographs of their home planet.
Left: The space station seen from Atlantis during the flyaround. Middle: Atlantis as seen from the space station during the flyaround, with a now empty payload bay. Right: Astronaut Nicole P. Stott looks back at the station, her home for three months, from the departing Atlantis.
On flight day nine, the joint crews held a brief farewell ceremony. European Space Agency astronaut Frank De Winne, the first European to command the space station, handed over command to NASA astronaut Williams. The two crews parted company and closed the hatches between the two spacecraft. The next day, with Wilmore at the controls, Atlantis undocked from the space station, having spent seven days as a single spacecraft. Wilmore completed a flyaround of the station, with the astronauts photographing it to document its condition. A final separation burn sent Atlantis on its way.
The astronauts used the shuttle’s arm to pick up the OBSS and perform a late inspection of Atlantis’ thermal protection system. On flight day 11, Hobaugh and Wilmore tested the orbiter’s reaction control system thrusters and flight control surfaces in preparation for the next day’s entry and landing. The entire crew busied themselves with stowing all unneeded equipment.
Left: Atlantis about to touch down at NASA’s Kennedy Space Center in Florida. Middle: Atlantis touches down. Right: Atlantis deploys its drag chute as it continues down the runway.
Left: Six of the STS-129 astronauts pose with Atlantis on the runway at NASA’s Kennedy Space Center in Florida. Right: The welcome home ceremony for the STS-129 crew at Ellington Field in Houston.
On Nov. 27, the astronauts closed Atlantis’ payload bay doors, donned their launch and entry suits, and strapped themselves into their seats, a special recumbent one for Stott who had spent the last three months in weightlessness. Hobaugh fired Atlantis’ two Orbital Maneuvering System engines to bring them out of orbit and head for a landing half an orbit later. He guided Atlantis to a smooth touchdown at KSC’s Shuttle Landing Facility.
The landing capped off a very successful STS-129 mission of 10 days, 19 hours, 16 minutes. The six astronauts orbited the planet 171 times. Stott spent 90 days, 10 hours, 45 minutes in space, completing 1,423 orbits of the Earth. After towing Atlantis to the OPF, engineers began preparing it for its next flight, STS-132 in May 2010. The astronauts returned to Houston for a welcoming ceremony at Ellington Field.
Enjoy the crew narrate a video about the STS-129 mission.
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