Feed aggregator
Ready, Set, Action! Our Sun is the Star in Dazzling Simulation
3 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
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 are only relatively slow up-flows, with very little twisting.NASA/Irina Kitiashvili and Timothy A. SandstromNASA 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, 2024, in Atlanta, Georgia. For more technical information, visit:
For news media: Members of the news media interested in covering this topic should reach out to the NASA Ames newsroom.
Share Details Last Updated Nov 21, 2024 Related Terms Explore More 2 min read Weld-ASSIST: Weldability Assessment for In-Space Conditions using a Digital Twin Article 1 day ago 5 min read NASA’s Chandra, Hubble Tune Into ‘Flame-Throwing’ Guitar Nebula Article 2 days ago 8 min read What is BioSentinel? Article 2 days ago Keep Exploring Discover More Topics From NASA Parker Solar ProbeOn a mission to “touch the Sun,” NASA’s Parker Solar Probe became the first spacecraft to fly through the corona…
Solar Storms and FlaresSolar storms and flares are eruptions from the Sun that can affect us here on Earth.
Solar System
Track the Solar Cycle with SunspotsParticipate in sunspot-counting activities using NASA telescopes or your own.
NASA: Mystery of Life’s Handedness Deepens
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)The mystery of why life uses molecules with specific orientations has deepened with a NASA-funded discovery that RNA — a key molecule thought to have potentially held the instructions for life before DNA emerged — can favor making the building blocks of proteins in either the left-hand or the right-hand orientation. Resolving this mystery could provide clues to the origin of life. The findings appear in research recently published in Nature Communications.
Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes (catalysts that speed up or regulate chemical reactions). Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acid building blocks in a huge variety of arrangements to make millions of different proteins. Some amino acid molecules can be built in two ways, such that mirror-image versions exist, like your hands, and life uses the left-handed variety of these amino acids. Although life based on right-handed amino acids would presumably work fine, the two mirror images are rarely mixed in biology, a characteristic of life called homochirality. It is a mystery to scientists why life chose the left-handed variety over the right-handed one.
A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite.NASA
DNA (deoxyribonucleic acid) is the molecule that holds the instructions for building and running a living organism. However, DNA is complex and specialized; it “subcontracts” the work of reading the instructions to RNA (ribonucleic acid) molecules and building proteins to ribosome molecules. DNA’s specialization and complexity lead scientists to think that something simpler should have preceded it billions of years ago during the early evolution of life. A leading candidate for this is RNA, which can both store genetic information and build proteins. The hypothesis that RNA may have preceded DNA is called the “RNA world” hypothesis.
If the RNA world proposition is correct, then perhaps something about RNA caused it to favor building left-handed proteins over right-handed ones. However, the new work did not support this idea, deepening the mystery of why life went with left-handed proteins.
The experiment tested RNA molecules that act like enzymes to build proteins, called ribozymes. “The experiment demonstrated that ribozymes can favor either left- or right-handed amino acids, indicating that RNA worlds, in general, would not necessarily have a strong bias for the form of amino acids we observe in biology now,” said Irene Chen, of the University of California, Los Angeles (UCLA) Samueli School of Engineering, corresponding author of the Nature Communications paper.
In the experiment, the researchers simulated what could have been early-Earth conditions of the RNA world. They incubated a solution containing ribozymes and amino acid precursors to see the relative percentages of the right-handed and left-handed amino acid, phenylalanine, that it would help produce. They tested 15 different ribozyme combinations and found that ribozymes can favor either left-handed or right-handed amino acids. This suggested that RNA did not initially have a predisposed chemical bias for one form of amino acids. This lack of preference challenges the notion that early life was predisposed to select left-handed-amino acids, which dominate in modern proteins.
“The findings suggest that life’s eventual homochirality might not be a result of chemical determinism but could have emerged through later evolutionary pressures,” said co-author Alberto Vázquez-Salazar, a UCLA postdoctoral scholar and member of Chen’s research group.
Earth’s prebiotic history lies beyond the oldest part of the fossil record, which has been erased by plate tectonics, the slow churning of Earth’s crust. During that time, the planet was likely bombarded by asteroids, which may have delivered some of life’s building blocks, such as amino acids. In parallel to chemical experiments, other origin-of-life researchers have been looking at molecular evidence from meteorites and asteroids.
“Understanding the chemical properties of life helps us know what to look for in our search for life across the solar system,” said co-author Jason Dworkin, senior scientist for astrobiology at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and director of Goddard’s Astrobiology Analytical Laboratory.
Dworkin is the project scientist on NASA’s OSIRIS-REx mission, which extracted samples from the asteroid Bennu and delivered them to Earth last year for further study.
“We are analyzing OSIRIS-REx samples for the chirality (handedness) of individual amino acids, and in the future, samples from Mars will also be tested in laboratories for evidence of life including ribozymes and proteins,” said Dworkin.
The research was supported by grants from NASA, the Simons Foundation Collaboration on the Origin of Life, and the National Science Foundation. Vázquez-Salazar acknowledges support through the NASA Postdoctoral Program, which is administered by Oak Ridge Associated Universities under contract with NASA.
Share Details Last Updated Nov 21, 2024 EditorWilliam SteigerwaldContactNancy N. Jonesnancy.n.jones@nasa.govLocationGoddard Space Flight Center Related Terms Explore More 2 min read NASA-Funded Study Examines Tidal Effects on Planet and Moon InteriorsNASA-supported scientists have developed a method to compute how tides affect the interiors of planets…
Article 2 weeks ago 2 min read NASA’s New Edition of Graphic Novel Features Europa ClipperNASA has released a new edition of Issue 4 of the Astrobiology Graphic History series.…
Article 3 weeks ago 4 min read NASA’s Perseverance Captures ‘Googly Eye’ During Solar Eclipse Article 3 weeks agoNASA’s Hubble Finds Sizzling Details About Young Star FU Orionis
- Hubble Home
- Overview
- Impact & Benefits
- Science
- Observatory
- Team
- News
- Multimedia
- More
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 AccretionOriginally 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
Download this image
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 OriUnderstanding 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 @NASAHubbleMedia 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
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Exploring the Birth of Stars
Hubble’s Night Sky Challenge
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.
Egg-shaped galaxies may be aligned to the black holes at their hearts, astronomers find
World's thinnest spaghetti won't please gourmands but may heal wounds
World's thinnest spaghetti won't please gourmands but may heal wounds
Bird Flu Has Infected Two Young People. Here’s Why Experts Are Concerned
Canada’s first human case of bird flu has left a teenager in critical condition as human infections continue to emerge in the western U.S.
Unreal Black Friday VR headset deals: Save up to $400 on various models in this HTC site-wide sale site-wide sale
SpaceX's 6th Starship megarocket launch looked amazing from space in astronaut and camera views (photo, video)
James Webb Space Telescope spots 1st 'Einstein zig-zag' — here's why scientists are thrilled
Carolyn Beatrice Parker’s Work on the Manhattan Project Inspired Her Birthplace Generations Later
This Black physicist’s work on the Manhattan Project inspired a County in Florida two generations after her death
First Rocks Returned from Moon’s Far Side Reveal Ancient Volcanic Activity
Samples from the far side of the moon gathered by China’s Chang’e-6 mission record eons of tumultuous lunar history
A sliver of lab-grown wood has been made from stem cells
A sliver of lab-grown wood has been made from stem cells
Are Fast Radio Bursts Caused by Interstellar Objects Crashing Into Neutron Stars?
Every now and then, astronomers will detect an odd kind of radio signal. So powerful it can outshine a galaxy, but lasting only milliseconds. They are known as fast radio bursts (FRBs). When they were first discovered a couple of decades ago, we had no idea what might cause them. We weren’t even sure if they were astronomical in origin. FRB’s were so localized and so short-lived, it was difficult to gather data on them. But with wide-field radio telescopes such as CHIME we can now observe FRBs regularly and have a pretty good idea of their source: magnetars.
Magnetars are neutron stars with immensely powerful magnetic fields. Now that we can localize FRBs, we have been able to match a few of them to the region of a neutron star. While most FRBs occur in distant galaxies, in 2020 we observed one within the Milky Way. The magnetar source also happened to be a pulsar, and astronomers were able to show that the FRB [correlated with a glitch in the pulsar’s rotation,](https://briankoberlein.com/blog/power-of-magnetism/) thus confirming the source. So we are fairly certain that FRBs are caused by neutron stars, but we are still uncertain about the exact mechanism.
One popular idea is that fast radio bursts are caused by magnetic realignments. This is what drives flares on the Sun. Over time, the Sun’s magnetic field lines can get twisted up until they snap into realignment, releasing energy. If a similar effect occurs on magnetars, the resulting snap would be much faster and more powerful. One difficulty with this idea is that FRBs are so short-lived that they are almost too fast for magnetic field lines to realign. So astronomers keep looking for new ideas, and one recently proposed argues that they are caused by impact events.
Distribution of FRB duration and ISB sizes compared. Credit: Pham, et alCollisions have long been known as the source of high-energy events. For example, some supernovae are caused by the collisions of neutron stars. We also know that comets and asteroids occasionally impact the Sun, so we would expect similar impacts to occur on neutron stars. In this new work, the authors propose that FRBs are caused when an interstellar body collides with a neutron star. The impact would trigger a powerful electromagnetic burst. To support their argument, the authors looked at the distribution of FRBs arranged by duration. The timing of FRBs follows a distribution similar to the distribution of solar system bodies. Not only that, the duration of an FRB seems to match the hypothetical duration of an impact event based on an object’s size.
While the data does seem to support the idea of impact-based FRBs, the study doesn’t solve all the mysteries surrounding these powerful bursts. We know, for example, that some FRBs are repeaters, meaning they occur multiple times from the same source. Some studies have shown that repeating FRBs are quasi-periodic, which would be difficult to explain through random collisions. It’s possible that repeating and non-repeating FRBs are caused by different mechanisms, though the data is still inconclusive on that point.
Reference: Pham, Dang, et al. “Fast Radio Bursts and Interstellar Objects.” arXiv preprint arXiv:2411.09135 (2024).
The post Are Fast Radio Bursts Caused by Interstellar Objects Crashing Into Neutron Stars? appeared first on Universe Today.
When Did Human Ancestors Start Using Tools?
The 3.2-million-year-old human ancestor known as Lucy sparked a revolution in scientists’ understanding of the origins of clever hands and stone tools
Suborbital rocket set to launch 6 experiments from Sweden's Arctic spaceport on Nov. 22
'Star Trek: Lower Decks' Season 5 episode 6: Is Ensign Olly really a demigod?
Copernicus Sentinel-1: radar vision for Copernicus
Meet Copernicus Sentinel-1 – this ground-breaking mission delivers continuous, all-weather, day-and-night imaging for land, ice and maritime monitoring.
Equipped with state-of-the-art C-band synthetic aperture radar (SAR), Sentinel-1 captures high-resolution data around the clock, in any weather, making it indispensable for detecting the subtle changes on Earth’s surface that remain hidden from the human eye.
Sentinel-1 data serves a multitude of critical applications: from ensuring the safety and efficiency of maritime traffic, tracking sea ice and icebergs, to monitoring structural integrity and natural hazards, such as earthquakes, landslides and volcanic activity.
Its enhanced radar technology provides precises precise information on ground movement, which is critical for urban planning, infrastructure resilience, subsidence risk assessment and geohazard monitoring.
Through consistent, long-term data collection, Sentinel-1 serves as a global asset, essential for environmental and safety monitoring worldwide. The mission is a beacon of innovation, advancing our understanding of our planet’s dynamic landscape.
This video features interviews with Mark Drinkwater, Head of Mission Sciences Division at ESA, Ramon Torres Cuesta, Sentinel-1 Project Manager at ESA and Julia Kubanek, Sentinel-1 Mission Scientist at ESA.