The Solar Orbiter discovered tiny jets from the Sun, potentially explaining the solar wind’s origin. This challenges traditional beliefs about the wind’s generation, with the new data suggesting an intermittent outflow. The findings could also have implications for understanding other stars’ atmospheres. Credit: ESA & NASA/Solar Orbiter/EUI Team; acknowledgment: Lakshmi Pradeep Chitta, Max Planck Institute for Solar System Research
The ESA/<span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
NASA
Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>NASA Solar Orbiter spacecraft has discovered a multitude of tiny jets of material escaping from the Sun’s outer atmosphere. Each jet lasts between 20 and 100 seconds, and expels <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
plasma
Plasma is one of the four fundamental states of matter, along with solid, liquid, and gas. It is an ionized gas consisting of positive ions and free electrons. It was first described by chemist Irving Langmuir in the 1920s.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>plasma at around 100 km/s (60 miles/s) or 360,000 km/h (220,000 mph). These jets could be the long-sought-after source of the solar wind.
Understanding the Solar Wind
The solar wind is composed of charged particles, known as plasma, that continuously escape the Sun. It propagates outwards through interplanetary space, colliding with anything in its path. When the solar wind collides with Earth’s magnetic field, it produces the aurorae.
Although the solar wind is a fundamental feature of the Sun, understanding how and where it is generated near the Sun has proven elusive and has been a key focus of study for decades. Now, thanks to its superior instrumentation, Solar Orbiter has taken us an important step closer.
This mosaic of images shows a multitude of tiny jets of material escaping from the Sun’s outer atmosphere. The images come from the ESA/NASA Solar Orbiter spacecraft. They show up as dark streaks across the solar surface in this mosaic. The images are ‘negatives’ meaning that although the jets are displayed as dark, they are bright flashes against the solar surface. Credit: ESA & NASA/Solar Orbiter/EUI Team; acknowledgment: Lakshmi Pradeep Chitta, Max Planck Institute for Solar System Research, CC BY-SA 3.0 IGO
High-resolution Imaging of the Sun’s Surface
The data comes from Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument. Images of the Sun’s south pole taken by EUI on March 30, 2022, reveal a population of faint, short-lived features that are associated with small jets of plasma being ejected from the Sun’s atmosphere.
“We could only detect these tiny jets because of the unprecedented high-resolution, high-cadence images produced by EUI,” says Lakshmi Pradeep Chitta, Max Planck Institute for Solar System Research, Germany, and the principal author on the paper describing this work. In particular, the images were taken in the extreme ultraviolet channel of EUI’s high resolution imager, which observes million-degree solar plasma at a wavelength of 17.4 nanometers.
Of particular importance is the fact that analysis shows that these features are caused by the expulsion of plasma from the solar atmosphere.
[embedded content] This movie was created from observations taken by the ESA/NASA Solar Orbiter spacecraft on March 30, 2022, between 04:30 and 04:55 <span class=”glossaryLink” aria-describedby=”tt” data-cmtooltip=”
UTC
Coordinated Universal Time or Universal Time Coordinated (UTC) is the primary time standard by which the world regulates clocks and time. Prior to 1972, this time was called Greenwich Mean Time (GMT) and is also known as "Z time" or "Zulu Time." It is, within about 1 second, mean solar time at 0° longitude.
” data-gt-translate-attributes=”[“attribute”:”data-cmtooltip”, “format”:”html”]”>UTC, and was previously released last year. It shows a ‘coronal hole’ near the Sun’s south pole. Subsequent analysis revealed many tiny jets being released during the observation. They show up as little flashes of bright light across the image. Each one expels charged particles, known as plasma, into space. The circle indicates the size of the Earth for scale. Credit: ESA & NASA/Solar Orbiter/EUI Team; acknowledgment: Lakshmi Pradeep Chitta, Max Planck Institute for Solar System Research
Magnetic Structures and the Solar Wind
Researchers have known for decades that a significant fraction of the solar wind is associated with magnetic structures called coronal holes – regions where the Sun’s magnetic field does not turn back down into the Sun. Instead, the magnetic field stretches deep into the Solar System.
Plasma can flow along these ‘open’ magnetic field lines, heading into the Solar System, creating the solar wind. But the question was: how did the plasma get launched?
The traditional assumption was that because the corona is hot, it will naturally expand and a portion of it will escape along the field lines. But these new results look into the coronal hole that was situated at the Sun’s south pole, and the individual jets that were revealed challenge the assumption that the solar wind is produced only in a steady continuous flow.
“One of the results here is that to a large extent, this flow is not actually uniform, the ubiquity of the jets suggests that the solar wind from coronal holes might originate as a highly intermittent outflow,” says Andrei Zhukov, Royal Observatory of Belgium, a collaborator on the work who led the Solar Orbiter observing campaign.
ESA’s Solar Orbiter mission will face the Sun from within the orbit of Mercury at its closest approach. Credit: ESA/ATG medialab
Energy Analysis of the Jets
The energy associated with each individual jet is small. At the top end of coronal phenomena are the X-class solar flares, and at the lower end are the so-called nanoflares. There is a billion times more energy in an X-flare than in a nanoflare. The tiny jets discovered by Solar Orbiter are even less energetic than that, manifesting around a thousand times less energy than a nanoflare, and channelling most of that energy into the expulsion of the plasma.
The ubiquity of them implied by the new observations suggests that they are expelling a substantial fraction of the material we see in the solar wind. And there could be even smaller, more frequent events providing yet more.
“I think it’s a significant step to find something on the disc that certainly is contributing to the solar wind,” says David Berghmans, Royal Observatory of Belgium, and principal investigator for the EUI instrument.
Future Observations and Broader Implications
Currently, Solar Orbiter is still circling the Sun close to its equator. So in these observations, EUI is looking across the south pole at a grazing angle.
“It’s harder to measure some of the properties of these tiny jets when seeing them edge-on, but in a few years, we will see them from a different perspective than any other telescopes or observatories so that together should help a lot,” says Daniel Müller, ESA Project Scientist for Solar Orbiter.
That is because as the mission continues, the spacecraft will gradually incline its orbit towards the polar regions. At the same time, the activity on the Sun will progress through the solar cycle and the coronal holes will begin popping up at many different latitudes, providing a unique new perspective.
All involved will be eager to see what fresh insights they can collect because this work extends further than our own Solar System.
The Sun is the only star whose atmosphere we can observe in such detail, but it is likely that the same process operates on other stars too. That turns these observations into the discovery of a fundamental astrophysical process.
Reference: “Picoflare jets power the solar wind emerging from a coronal hole on the Sun” by L. P. Chitta, A. N. Zhukov, D. Berghmans, H. Peter, S. Parenti, S. Mandal, R. Aznar Cuadrado, U. Schühle, L. Teriaca, F. Auchère, K. Barczynski, É. Buchlin, L. Harra, E. Kraaikamp, D. M. Long, L. Rodriguez, C. Schwanitz, P. J. Smith, C. Verbeeck and D. B. Seaton, 24 August 2023, Science. DOI: 10.1126/science.ade5801
Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
The European Space Agency is fast-tracking a new mission called Ramses, which will fly to near-Earth asteroid 99942 Apophis and join the space rock in 2029 when it comes very close to our planet — closer even than the region where geosynchronous satellites sit.
Ramses is short for Rapid Apophis Mission for Space Safety and, as its name suggests, is the next phase in humanity’s efforts to learn more about near-Earth asteroids (NEOs) and how we might deflect them should one ever be discovered on a collision course with planet Earth.
In order to launch in time to rendezvous with Apophis in February 2029, scientists at the European Space Agency have been given permission to start planning Ramses even before the multinational space agency officially adopts the mission. The sanctioning and appropriation of funding for the Ramses mission will hopefully take place at ESA’s Ministerial Council meeting (involving representatives from each of ESA’s member states) in November of 2025. To arrive at Apophis in February 2029, launch would have to take place in April 2028, the agency says.
This is a big deal because large asteroids don’t come this close to Earth very often. It is thus scientifically precious that, on April 13, 2029, Apophis will pass within 19,794 miles (31,860 kilometers) of Earth. For comparison, geosynchronous orbit is 22,236 miles (35,786 km) above Earth’s surface. Such close fly-bys by asteroids hundreds of meters across (Apophis is about 1,230 feet, or 375 meters, across) only occur on average once every 5,000 to 10,000 years. Miss this one, and we’ve got a long time to wait for the next.
When Apophis was discovered in 2004, it was for a short time the most dangerous asteroid known, being classified as having the potential to impact with Earth possibly in 2029, 2036, or 2068. Should an asteroid of its size strike Earth, it could gouge out a crater several kilometers across and devastate a country with shock waves, flash heating and earth tremors. If it crashed down in the ocean, it could send a towering tsunami to devastate coastlines in multiple countries.
Over time, as our knowledge of Apophis’ orbit became more refined, however, the risk of impact greatly went down. Radar observations of the asteroid in March of 2021 reduced the uncertainty in Apophis’ orbit from hundreds of kilometers to just a few kilometers, finally removing any lingering worries about an impact — at least for the next 100 years. (Beyond 100 years, asteroid orbits can become too unpredictable to plot with any accuracy, but there’s currently no suggestion that an impact will occur after 100 years.) So, Earth is expected to be perfectly safe in 2029 when Apophis comes through. Still, scientists want to see how Apophis responds by coming so close to Earth and entering our planet’s gravitational field.
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“There is still so much we have yet to learn about asteroids but, until now, we have had to travel deep into the solar system to study them and perform experiments ourselves to interact with their surface,” said Patrick Michel, who is the Director of Research at CNRS at Observatoire de la Côte d’Azur in Nice, France, in a statement. “Nature is bringing one to us and conducting the experiment itself. All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface.”
The Goldstone radar’s imagery of asteroid 99942 Apophis as it made its closest approach to Earth, in March 2021. (Image credit: NASA/JPL–Caltech/NSF/AUI/GBO)
By arriving at Apophis before the asteroid’s close encounter with Earth, and sticking with it throughout the flyby and beyond, Ramses will be in prime position to conduct before-and-after surveys to see how Apophis reacts to Earth. By looking for disturbances Earth’s gravitational tidal forces trigger on the asteroid’s surface, Ramses will be able to learn about Apophis’ internal structure, density, porosity and composition, all of which are characteristics that we would need to first understand before considering how best to deflect a similar asteroid were one ever found to be on a collision course with our world.
Besides assisting in protecting Earth, learning about Apophis will give scientists further insights into how similar asteroids formed in the early solar system, and, in the process, how planets (including Earth) formed out of the same material.
One way we already know Earth will affect Apophis is by changing its orbit. Currently, Apophis is categorized as an Aten-type asteroid, which is what we call the class of near-Earth objects that have a shorter orbit around the sun than Earth does. Apophis currently gets as far as 0.92 astronomical units (137.6 million km, or 85.5 million miles) from the sun. However, our planet will give Apophis a gravitational nudge that will enlarge its orbit to 1.1 astronomical units (164.6 million km, or 102 million miles), such that its orbital period becomes longer than Earth’s.
It will then be classed as an Apollo-type asteroid.
Ramses won’t be alone in tracking Apophis. NASA has repurposed their OSIRIS-REx mission, which returned a sample from another near-Earth asteroid, 101955 Bennu, in 2023. However, the spacecraft, renamed OSIRIS-APEX (Apophis Explorer), won’t arrive at the asteroid until April 23, 2029, ten days after the close encounter with Earth. OSIRIS-APEX will initially perform a flyby of Apophis at a distance of about 2,500 miles (4,000 km) from the object, then return in June that year to settle into orbit around Apophis for an 18-month mission.
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Furthermore, the European Space Agency still plans on launching its Hera spacecraft in October 2024 to follow-up on the DART mission to the double asteroid Didymos and Dimorphos. DART impacted the latter in a test of kinetic impactor capabilities for potentially changing a hazardous asteroid’s orbit around our planet. Hera will survey the binary asteroid system and observe the crater made by DART’s sacrifice to gain a better understanding of Dimorphos’ structure and composition post-impact, so that we can place the results in context.
The more near-Earth asteroids like Dimorphos and Apophis that we study, the greater that context becomes. Perhaps, one day, the understanding that we have gained from these missions will indeed save our planet.
