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Neptune Completes Its First Circuit Around The Sun Since Its Discovery
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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
General Ames Research Center Heliophysics Solar Dynamics Observatory (SDO) Sunspots The Sun Explore More
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Parker Solar Probe
On a mission to “touch the Sun,” NASA’s Parker Solar Probe became the first spacecraft to fly through the corona…
Solar Storms and Flares
Solar storms and flares are eruptions from the Sun that can affect us here on Earth.
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Track the Solar Cycle with Sunspots
Participate in sunspot-counting activities using NASA telescopes or your own.
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By NASA
Artist’s concept of a young, newly discovered planet, exposed to observation by a warped debris disk. Credit: Robert Hurt, Caltech-IPAC. The discovery
A huge planet with a long name – IRAS 04125+2902 b – is really just a baby: only 3 million years old. And because such infant worlds are usually hidden inside obscuring disks of debris, it is the youngest planet so far discovered using the dominant method of planet detection.
Key facts
The massive planet, likely still glowing from the heat of its formation, lies in the Taurus Molecular Cloud, an active stellar nursery with hundreds of newborn stars some 430 light-years away. The cloud’s relative closeness makes it a prime target for astronomers. But while the cloud offers deep insight into the formation and evolution of young stars, their planets are usually a closed book to telescopes like TESS, the Transiting Exoplanet Survey Satellite. These telescopes rely on the “transit method,” watching for the slight dip in starlight when a planet crosses the face of its host star. But such planetary systems must be edge-on, from Earth’s vantage point, for the transit method to work. Very young star systems are surrounded by disks of debris, however, blocking our view of any potentially transiting planets.
A research team has just reported an extraordinary stroke of luck. Somehow, the outer debris disk surrounding this newborn planet, IRAS 04125+2902 b, has been sharply warped, exposing the baby world to extensive transit observations by TESS.
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While the warped outer disk is a great coincidence, it’s also a great mystery. Possible explanations include a migration of the planet itself, moving closer to the star and, in the process, diverging from the orientation of the outer disk – so that, from Earth, the planet’s orbit is edge-on, crossing the face of the star, but the outer disk remains nearly face-on to us. One problem with this idea: Moving a planet so far out of alignment with its parent disk would likely require another (very large) object in this system. None has been detected so far.
The system’s sun happens to have a distant stellar companion, also a possible culprit in the warping of the outer disk. The angle of the orbit of the companion star, however, matches that of the planet and its parent star. Stars and planets tend to take the gravitational path of least resistance, so such an arrangement should push the disk into a closer alignment with the rest of the system – not into a radical departure.
Another way to get a “broken” outer disk, the study authors say, would not involve a companion star at all. Stellar nurseries like the Taurus Molecular Cloud can be densely packed, busy places. Computer simulations show that rains of infalling material from the surrounding star-forming region could be the cause of disk-warping. Neither simulations nor observations have so far settled the question of whether warped or broken disks are common or rare in such regions.
Fun facts
Combining TESS’s transit measurements with another way of observing planets yields more information about the planet itself. We might call this second approach the “wobble” method. The gravity of a planet tugs its star one way, then another, as the orbiting planet makes its way around the star. And that wobble can be detected by changes in the light from the star, picked up by specialized instruments on Earth. Such “radial velocity” measurements of this planet reveal that its mass, or heft, amounts to no more than about a third of our own Jupiter. But the transit data shows the planet’s diameter is about the same. That means the planet has a comparatively low density and, likely, an inflated atmosphere. So this world probably is not a gas giant like Jupiter. Instead, it could well be a planet whose atmosphere will shrink over time. When it finally settles down, it could become a gaseous “mini-Neptune” or even a rocky “super-Earth.” These are the two most common planet types in our galaxy – despite the fact that neither type can be found in our solar system.
The discoverers
A science team led by astronomer Madyson G. Barber of the University of North Carolina at Chapel Hill published the study, “A giant planet transiting a 3 Myr protostar with a misaligned disk,” in the journal Nature in November 2024.
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By NASA
5 min read
5 Surprising NASA Heliophysics Discoveries Not Related to the Sun
With NASA’s fleet of heliophysics spacecraft, scientists monitor our Sun and investigate its influences throughout the solar system. However, the fleet’s constant watch and often-unique perspectives sometimes create opportunities to make discoveries that no one expected, helping us to solve mysteries about of the solar system and beyond.
Here are five examples of breakthroughs made by NASA heliophysics missions in other fields of science.
This graphic shows missions in NASA’s Heliophysics Division fleet as of July 2024. NASA Thousands and Thousands of Comets
The SOHO mission — short for Solar and Heliospheric Observatory, which is a joint mission between ESA (European Space Agency) and NASA — has a coronagraph that blocks out the Sun in order to see the Sun’s faint outer atmosphere, or corona.
It turns out SOHO’s coronagraph also makes it easy to spot sungrazing comets, those that pass so close to the Sun that other observatories can’t see them against the brightness of our star.
Before SOHO was launched in December 1995, fewer than 20 sungrazing comets were known. Since then, SOHO has discovered more than 5,000.
The vast number of comets discovered using SOHO has allowed scientists to learn more about sungrazing comets and identify comet families, descended from ancestor comets that broke up long ago.
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Two sungrazing comets fly close to the Sun in these images captured by ESA/NASA’s SOHO (Solar and Heliospheric Observatory). They were the 3,999th and 4,000th comets discovered in SOHO images. ESA/NASA/SOHO/Karl Battams Dimming of a Supergiant
In late 2019, the supergiant star Betelgeuse began dimming unexpectedly. Telescopes all over the world — and around it — tracked these changes until a few months later when Betelgeuse appeared too close to the Sun to observe. That’s when NASA’s STEREO (Sun-watching Solar Terrestrial Relations Observatory (STEREO) came to the rescue.
For several weeks in the middle of 2020, STEREO was the only observatory able to see Betelgeuse. At the time, the STEREO-A spacecraft was trailing behind Earth, at a vantage point where Betelgeuse was still far enough away from the Sun to be seen. This allowed astronomers to keep tabs on the star while it was out of view from Earth.
STEREO’s observations revealed another unexpected dimming between June and August of 2020, when ground-based telescopes couldn’t view the star.
Astronomers later concluded that these dimming episodes were caused by an ejection of mass from Betelgeuse — like a coronal mass ejection from our Sun but with about 400 times more mass — which obscured part of the star’s bright surface.
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The background image shows the star Betelgeuse as seen by the Heliospheric Imager aboard NASA’s STEREO (Solar Terrestrial Relations Observatory) spacecraft. The inset figure shows measurements of Betelgeuse’s brightness taken by different observatories from late 2018 to late 2020. STEREO’s observations, marked in red, revealed an unexpected dimming in mid-2020 when Betelgeuse appeared too close to the Sun for other observatories to view it. NASA/STEREO/HI (background); Dupree et al. (inset) The Glowing Surface of Venus
NASA’s Parker Solar Probe studies the Sun’s corona up close — by flying through it. To dive into the Sun’s outer atmosphere, the spacecraft has flown past Venus several times, using the planet’s gravity to fling itself closer and closer to the Sun.
On July 11, 2020, during Parker’s third Venus flyby, scientists used Parker’s wide-field imager, called WISPR, to try to measure the speed of the clouds that obscure Venus’ surface. Surprisingly, WISPR not only observed the clouds, it also saw through them to the surface below.
The images from that flyby and the next (in 2021) revealed a faint glow from Venus’ hot surface in near-infrared light and long wavelengths of red (visible) light that maps distinctive features like mountainous regions, plains, and plateaus.
Scientists aimed WISPR at Venus again on Nov. 6, 2024, during Parker’s seventh flyby, observing a different part of the planet than previous flybys. With these images, they’re hoping to learn more about Venus’ surface geology, mineralogy, and evolution.
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As Parker Solar Probe flew by Venus on its fourth flyby, it captured these images, strung into a video, showing bright and dark features on the nightside surface of the planet. NASA/APL/NRL The Brightest Gamma-Ray Burst
You’ve heard of the GOAT. But have you heard of the BOAT?
It stands for the “brightest of all time”, a gamma-ray burst discovered on Oct. 9, 2022.
A gamma-ray burst is a brief but intense eruption of gamma rays in space, lasting from seconds to hours.
This one, named GRB 221009A, glowed brilliantly for about 10 minutes in the constellation Sagitta before slowly fading.
The burst was detected by dozens of spacecraft, including NASA’s Wind, which studies the perpetual flow of particles from the Sun, called the solar wind, just before it reaches Earth.
Wind and NASA’s Fermi Gamma-Ray Space Telescope measured the brightness of GRB 221009A, showing that it was 70 times brighter than any other gamma-ray burst ever recorded by humans — solidifying its status as the BOAT.
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Astronomers think GRB 221009A represents the birth of a new black hole formed within the heart of a collapsing star. In this artist’s concept, the black hole drives powerful jets of particles traveling near the speed of light. The jets emit X-rays and gamma rays as they stream into space. NASA/Swift/Cruz deWilde A Volcano Blasts Its Way to Space
NASA’s ICON (Ionospheric Connection Explorer) launched in 2019 to study how Earth’s weather interacts with weather from space. When the underwater Hunga Tonga-Hunga Ha‘apai volcano erupted on Jan. 15, 2022, ICON helped show that the volcano produced more than ash and tsunami waves — its effects reached the edge of space.
In the hours after the eruption, ICON detected hurricane-speed winds in the ionosphere — Earth’s electrified upper atmospheric layer at the edge of space. ICON clocked the wind speeds at up to 450 miles per hour, making them the strongest winds the mission had ever measured below 120 miles altitude.
The ESA Swarm mission revealed that these extreme winds altered an electric current in the ionosphere called the equatorial electrojet. After the eruption, the equatorial electrojet surged to five times its normal peak power and dramatically flipped direction.
Scientists were surprised that a volcano could affect the electrojet so severely — something they’d only seen during a strong geomagnetic storm caused by an eruption from the Sun.
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The Hunga Tonga-Hunga Ha’apai eruption on Jan. 15, 2022, caused many effects, some illustrated here, that were felt around the world and even into space. Some of those effects, like extreme winds and unusual electric currents were picked up by NASA’s ICON (Ionospheric Connection Explorer) mission and ESA’s (the European Space Agency) Swarm. Illustration is not to scale. NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith By Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Last Updated Nov 20, 2024 Related Terms
Comets Fermi Gamma-Ray Space Telescope Gamma-Ray Bursts Goddard Space Flight Center Heliophysics Heliophysics Division ICON (Ionospheric Connection Explorer) Parker Solar Probe (PSP) SOHO (Solar and Heliospheric Observatory) Stars STEREO (Solar TErrestrial RElations Observatory) The Sun The Sun & Solar Physics Uncategorized Venus Volcanoes Wind Mission Explore More
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By European Space Agency
Video: 00:04:30 Explore the immense power of water as ESA’s Mars Express takes us on a flight over curving channels, streamlined islands and muddled ‘chaotic terrain’ on Mars, soaking up rover landing sites along the way.
This beautiful flight around the Oxia Palus region of Mars covers a total area of approximately 890 000 km2, more than twice the size of Germany. Central to the tour is one of Mars’s largest outflow channels, Ares Vallis. It stretches for more than 1700 km2 and cascades down from the planet’s southern highlands to enter the lower-lying plains of Chryse Planitia.
Billions of years ago, water surged through Ares Vallis, neighbouring Tiu Vallis, and numerous other smaller channels, creating many of the features observed in this region today.
Enjoy the flight!
After enjoying a spectacular global view of Mars we focus in on the area marked by the white rectangle. Our flight starts over the landing site of NASA’s Pathfinder mission, whose Sojourner rover explored the floodplains of Ares Vallis for 12 weeks in 1997.
Continuing to the south, we pass over two large craters named Masursky and Sagan. The partially eroded crater rim of Masursky in particular suggests that water once flowed through it, from nearby Tiu Vallis.
The Masurky Crater is filled with jumbled blocks, and you can see many more as we turn north to Hydaspis Chaos. This ‘chaotic terrain’ is typical of regions influenced by massive outflow channels. Its distinctive muddled appearance is thought to arise when subsurface water is suddenly released from underground to the surface. The resulting loss of support from below causes the surface to slump and break into blocks of various sizes and shapes.
Just beyond this chaotic array of blocks is Galilaei crater, which has a highly eroded rim and a gorge carved between the crater and neighbouring channel. It is likely that the crater once contained a lake, which flooded out into the surroundings. Continuing on, we see streamlined islands and terraced river banks, the teardrop-shaped island ‘tails’ pointing in the downstream direction of the water flow at the time.
Crossing over Ares Vallis again, the flight brings us to the smoother terrain of Oxia Planum and the planned landing site for ESA’s ExoMars Rosalind Franklin rover. The primary goal of the mission is to search for signs of past or present life on Mars, and as such, this once water-flooded region is an ideal location.
Zooming out, the flight ends with a stunning bird’s-eye view of Ares Vallis and its fascinating water-enriched neighbourhood.
Disclaimer: This video is not representative of how Mars Express flies over the surface of Mars. See processing notes below.
How the movie was made
This film was created using the Mars Express High Resolution Stereo Camera Mars Chart (HMC30) data, an image mosaic made from single orbit observations of the High Resolution Stereo Camera (HRSC). The mosaic, centred at 12°N/330°E, is combined with topography information from the digital terrain model to generate a three-dimensional landscape.
For every second of the movie, 50 separate frames are rendered following a predefined camera path in the scene. A three-fold vertical exaggeration has been applied. Atmospheric effects such as clouds and haze have been added to conceal the limits of the terrain model. The haze starts building up at a distance of 300 km.
The HRSC camera on Mars Express is operated by the German Aerospace Center (DLR). The systematic processing of the camera data took place at the DLR Institute for Planetary Research in Berlin-Adlershof. The working group of Planetary Science and Remote Sensing at Freie Universität Berlin used the data to create the film.
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