SPACE/COSMOS
Scientists share early results from NASA’s solar eclipse experiments
At a press briefing on Tuesday, Dec. 10, scientists attending the annual meeting of the American Geophysical Union in Washington, D.C., reported some early results from NASA-funded solar eclipse experiments conducted on April 8, 2024
NASA/Goddard Space Flight Center
video:
This preliminary movie from the Citizen CATE 2024 project stitches together polarized images of the solar corona taken from different sites during the total solar eclipse on April 8, 2024.
view moreCredit: SwRI/Citizen CATE 2024/Dan Seaton/Derek Lamb
On April 8, 2024, a total solar eclipse swept across North America, from the western shores of Mexico, through the United States, and into northeastern Canada. For the eclipse, NASA helped fund numerous research projects and called upon citizen scientists in support of NASA's goal to understand how our home planet is affected by the Sun – including, for example, how our star interacts with Earth's atmosphere and affects radio communications.
At a press briefing on Tuesday, Dec. 10, scientists attending the annual meeting of the American Geophysical Union in Washington, D.C., reported some early results from a few of these eclipse experiments.
“Scientists and tens of thousands of volunteer observers were stationed throughout the Moon’s shadow,” said Kelly Korreck, eclipse program manager at NASA Headquarters in Washington. “Their efforts were a crucial part of the Heliophysics Big Year – helping us to learn more about the Sun and how it affects Earth’s atmosphere when our star’s light temporarily disappears from view.”
Changes in the Corona
On April 8, the Citizen CATE 2024 (Continental-America Telescopic Eclipse) project stationed 35 observing teams from local communities from Texas to Maine to capture images of the Sun’s outer atmosphere, or corona, during totality. Their goal is to see how the corona changed as totality swept across the continent.
On Dec. 10, Sarah Kovac, the CATE project manager at the Southwest Research Institute in Boulder, Colorado, reported that, while a few teams were stymied by clouds, most observed totality successfully — collecting over 47,000 images in all.
These images were taken in polarized light, or light oriented in different directions, to help scientists better understand the processes that shape the corona.
Kovac shared the first cut of a movie created from these images. The project is still stitching together all the images into the final, hour-long movie, for release at a later time.
“The beauty of CATE 2024 is that we blend cutting-edge professional science with community participants from all walks of life,” Kovac said. “The dedication of every participant made this project possible.”
Meanwhile, 50,000 feet above the ground, two NASA WB-57 aircraft chased the eclipse shadow as it raced across the continent, observing above the clouds and extending their time in totality to approximately 6 minutes and 20 seconds.
On board were cameras and spectrometers (instruments that analyze different wavelengths of light) built by multiple research teams to study the corona.
On Dec. 10, Shadia Habbal of the University of Hawaii, who led one of the teams, reported that their instruments collected valuable data, despite one challenge. Cameras they had mounted on the aircraft’s wings experienced unexpected vibrations, which caused some of the images to be slightly blurred.
However, all the cameras captured detailed images of the corona, and the spectrometers, which were located in the nose of the aircraft, were not affected. The results were so successful, scientists are already planning to fly similar experiments on the aircraft again.
“The WB-57 is a remarkable platform for eclipse observations that we will try to capitalize on for future eclipses,” Habbal said.
Affecting the Atmosphere
On April 8, amateur or “ham” radio operators sent and received signals to one another before, during, and after the eclipse as part of the Ham Radio Science Citizen Investigation (HamSCI) Festivals of Eclipse Ionospheric Science. More than 6,350 amateur radio operators generated over 52 million data points to observe how the sudden loss of sunlight during totality affects their radio signals and the ionosphere, an electrified region of Earth’s upper atmosphere.
Radio communications inside and outside the path of totality improved at some frequencies (from 1-7 MHz), showing there was a reduction in ionospheric absorption. At higher frequencies (10 MHz and above), communications worsened.
Results using another technique, which bounced high-frequency radio waves (3-30 MHz) off the ionosphere, suggests that the ionosphere ascended in altitude during the eclipse and then descended to its normal height afterward.
“The project brings ham radio operators into the science community,” said Nathaniel Frissell, a professor at the University of Scranton in Pennsylvania and lead of HamSCI. “Their dedication to their craft made this research possible.”
Also looking at the atmosphere, the Nationwide Eclipse Ballooning Project organized student groups across the U.S. to launch balloons into the shadow of the Moon as it crossed the country in April 2024 and during a solar eclipse in October 2023. Teams flew weather sensors and other instruments to study the atmospheric response to the cold, dark shadow.
This research, conducted by over 800 students, confirmed that eclipses can generate ripples in Earth’s atmosphere called atmospheric gravity waves. Just as waves form in a lake when water is disturbed, these waves also form in the atmosphere when air is disturbed. This project, led by Angela Des Jardins of Montana State University in Bozeman, also confirmed the presence of these waves during previous solar eclipses. Scientists think the trigger for these waves is a “hiccup” in the tropopause, a layer in Earth’s atmosphere, similar to an atmospheric effect that is observed during sunset.
“Half of the teams had little to no experience ballooning before the project,” said Jie Gong, a team science expert and atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “But their hard work and research was vital in this finding.”
By Abbey Interrante and Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
This image of the total solar eclipse is a combination of 30 50-millisecond exposures taken with a camera mounted on one of NASA’s WB-57 aircraft on April 8, 2024. It was captured in a wavelength of light emitted by ionized iron atoms. This Fe XIV emission highlights electrified gas, called plasma, at a specific temperature (around 3.2 million degrees Fahrenheit) that often reveals arch-like structures in the corona.
Credit
B. Justen, O. Mayer, M. Justen, S. Habbal, and M. Druckmuller
The eclipse’s shadow was captured from a camera aboard Virginia Tech’s balloon as part of the Nationwide Eclipse Ballooning Project on April 8, 2024.
Credit
Nationwide Eclipse Ballooning Project/Virginia Tech
Students from Case Western Reserve University operate radios during the 2024 total solar eclipse.
Credit
HamSCI/Case Western Reserve University
A new discovery about the source of the vast energy in cosmic rays
Columbia University
Ultra-high energy cosmic rays, which emerge in extreme astrophysical environments—like the roiling environments near black holes and neutron stars—have far more energy than the energetic particles that emerge from our sun. In fact, the particles that make up these streams of energy have around 10 million times the energy of particles accelerated in the most extreme particle environment on earth, the human-made Large Hadron Collider.
Where does all that energy come from? For many years, scientists believed it came from shocks that occur in extreme astrophysical environments—when, for example, a star explodes before forming a black hole, causing a huge explosion that kicks up particles.
That theory was plausible, but, according to new research published this week in The Astrophysical Journal Letters, the observations are better explained by a different mechanism. The source of the cosmic rays’ energy, the researchers found, is more likely magnetic turbulence. The paper’s authors found that magnetic fields in these environments tangle and turn, rapidly accelerating particles and sharply increasing their energy up to an abrupt cutoff.
“These findings help solve enduring questions that are of great interest to both astrophysicists and particle physicists about how these cosmic rays get their energy,” said Luca Comisso, associate research scientist in the Columbia Astrophysics Lab, and one of the paper’s authors.
The paper complements research published last year by Comisso and collaborators on the sun’s energetic particles, which they also found emerge from magnetic fields in the sun’s corona. In that paper, Comisso and his colleagues discovered ways to better predict where those energetic particles would emerge.
Ultra-high energy cosmic rays are orders of magnitude more powerful than the sun’s energetic particles: They can reach up to 1020 electron volts, whereas particles from the Sun can reach up to 1010 electron volts, a 10-order-of-magnitude difference. (To give an idea of this vast difference in scale, consider the difference in weight between a grain of rice with a mass of about 0.05 grams and a 500-ton Airbus A380, the world’s largest passenger aircraft.) “It’s interesting that these two extremely different environments share something in common: their magnetic fields are highly tangled and this tangled nature is crucial for energizing particles,” Comisso said.
“Remarkably, the data on ultra-high energy cosmic rays clearly prefers the predictions of magnetic turbulence over those of shock acceleration. This is a real breakthrough for the field,” said Glennys R. Farrar, an author on the paper and professor of physics at New York University.
The research was supported by the National Science Foundation.
Journal
The Astrophysical Journal Letters
Method of Research
Computational simulation/modeling
Subject of Research
Not applicable
Article Title
Ultra-High-Energy Cosmic Rays Accelerated by Magnetically Dominated Turbulence
Article Publication Date
10-Dec-2024
By Dr. Tim Sandle
December 10, 2024
DIGITAL JOURNAL
A 'selfie' taken by China's Zhurong Mars rover during the Tianwen 1 mission. Source - China News Service, https://www.youtube.com/watch?v=BnrwZVJ_VAQ. CC SA 3.0.
One of the main challenges that deep space flight presents to astronauts is radiation. Space vehicles can be shielded but with currently technology this remains limited. One of the nearer-to-home challenges for a mission to Mars with a human crew is radiation. Hence, a significant hazard for astronauts traveling to Mars will be overcoming exposure to high energy radiation from the solar wind, solar storms, and galactic cosmic rays that originate outside of our solar system.
A new chemical and microbiological discovery, from Northwestern University and the Uniformed Services University (USU), finds how simple metabolites can combine to form a powerful antioxidant. It is through this powerful antioxidant the bacterium Deinococcus radiodurans can withstand radiation doses 28,000 times greater than what would kill a human. The bacterium is the second known most radiation-resistant micorganism (the most resistant are the archaeon Thermococcus gammatolerans).
The benefit of the research is aiding scientific understanding of how the antioxidant works and this insight could help to drive the development of ‘designer’ antioxidants to shield astronauts from cosmic radiation (a decapeptide called DP1).
The reason that the spherical D. radiodurans is so resistant to gamma radiation doses is the presence of a collection of simple metabolites, which combine with manganese to form the powerful antioxidant. This is all the more remarkable given that the bacterium does not form spores (the normal morphology linked to the most resistant bacterial species).
In a new study, the researchers characterized a synthetic designer antioxidant, called MDP, which was inspired by D. radiodurans’ resilience. They found, in relation to the extremophile, MDP’s components — manganese ions, phosphate and a small peptide — form a ternary complex that is a much more powerful protectant from radiation damage than manganese combined with either of the other individual components alone.
This discovery could eventually lead to new synthetic antioxidants specifically tailored to human needs. Applications include protecting astronauts from intense cosmic radiation during deep-space missions, preparing for radiation emergencies and producing radiation-inactivated vaccines.
The research builds on previous inquiries that sought to better understand D. radiodurans’ predicted ability to withstand radiation on Mars. This used an advanced spectroscopy technique to measure the accumulation of manganese antioxidants in the microbes’ cells. This revealed the size of the radiation dose that a microorganism can survive directly correlates with the amount of manganese antioxidants it contains (more manganese antioxidants mean more resistance to intense radiation).
D. radiodurans can survive 25,000 Grays in its normal vegetative state (after this, DNA cleavage occurs); however, when dried and frozen (as it might be on the hull of a spacecraft), the bacterium can survive 140,000 Grays of radiation, a dose 28,000 times greater than what would kill a human. A Gray is defined as the absorption of one joule of radiation energy per kilogram of matter. Against most microbes, 25 to 50,000 Grays are sufficient to achieve demonstrable sterilisation.
For the current study, the scientists identified a decapeptide called DP1. When combined with phosphate and manganese, DP1 forms the free-radical-scavenging agent MDP, which successfully protects cells and proteins against radiation damage.
By using advanced paramagnetic resonance spectroscopy, the scientists further revealed that the active ingredient of MDP is a ternary complex — a precise assembly of phosphate and peptide bound to manganese.
The research appears in the journal Proceedings of the National Academy of Sciences. The research is titled “The ternary complex of Mn2+, synthetic decapeptide DP1 (DEHGTAVMLK) and orthophosphate is a superb antioxidant.”
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