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Eclipses inspire wonder and bring people together to observe a spectacular celestial phenomenon, but these cosmic events also enable scientists to solve the mysteries of the solar system.
During the total solar eclipse on April 8, when the moon will temporarily obscure the face of the sun from view for millions of people across Mexico, the United States and Canada, multiple experiments will be underway to better understand some of the most unresolved questions about the golden. orb.
NASA will launch WB-57 sounding rockets and high-altitude aircraft to research aspects of the sun and Earth that are only possible during an eclipse. The efforts are part of a long history of efforts to collect valuable data and observations when the moon temporarily blocks sunlight.
Perhaps one of the most famous scientific milestones related to eclipses occurred on May 29, 1919, when a total solar eclipse provided evidence for Albert Einstein’s theory of general relativity, which the scientist systematically described in First 1916, according to NASA.
Einstein hypothesized that gravity is the result of the warping of time and space, distorting the very fabric of the universe. For example, Einstein suggested that the gravitational influence of a large object like the sun could deflect the light emitted by another object, such as a star almost behind it, making the object appear slightly further away from Earth’s perspective. A scientific expedition to observe stars from Brazil and West Africa, led by English astronomer Sir Arthur Eddington during the 1919 eclipse, showed that some stars appeared to be in the wrong place, confirming Einstein’s theory.
This finding is just one of many scientific lessons learned about eclipses.
During the 2017 eclipse that crossed the US, NASA and other space agencies made observations using 11 different spacecraft and two high-altitude airplanes.
Data collected during that eclipse helped scientists accurately predict what the sun’s corona, or hot outer atmosphere, would look like during eclipses in 2019 and 2021. Despite its blazing temperatures, the appearance of the corona smaller than the bright surface of the sun, but it is smaller. appears as a halo around the sun during an eclipse when most of the sunlight is blocked by the moon, which makes it easier to study.
Why the corona is millions of degrees hotter than the actual surface of the sun is one of the enduring mysteries about our star. A study carried out in 2021 revealed some new clues, which showed that the corona has a constant temperature, despite the fact that the sun undergoes an 11-year cycle of decreasing and increasing activity. The results were possible thanks to more than a decade of eclipse observations, according to NASA.
Although it has been quieter during previous eclipses, the sun is reaching the peak of its activity, known as solar maximum, this year, giving scientists a rare opportunity.
And during the eclipse on April 8, citizen scientists and teams of researchers could make new discoveries that could advance our understanding of our corner of the universe.
Launching rockets into an eclipse
Observing the sun during eclipses also helps scientists better understand how solar material flows from the sun. Charged particles called plasma create space weather that interacts with the upper layer of the Earth’s atmosphere, called the ionosphere. The region acts as a boundary between the Earth’s lower atmosphere and space.
Energetic solar activity released by the sun during solar maximum could disrupt the International Space Station and communications infrastructure. Many low-Earth orbit satellites and radio waves operate in the ionosphere, meaning dynamic space weather affects GPS and long-range radio communications.
Experiments to study the ionosphere during the eclipse include high-altitude balloons and a citizen science effort that calls for the participation of amateur radio operators. Operators in different locations will record the strength of their signals and how far they travel during the eclipse to see how changes in the ionosphere affect the signals. Researchers also performed this experiment during the annular eclipse of October 2023, when the moon did not completely block sunlight, and the data are still being analyzed.
In another repeat experiment, three sounding rockets will take off in succession from NASA’s Wallops Flight Facility in Virginia before, during and after the eclipse to measure how the sudden cancellation of sunlight affects Earth’s upper atmosphere.
Aroh Barjatya, a professor of engineering physics at Embry-Riddle Aeronautical University in Daytona Beach, Florida, is leading the experiment, called Atmospheric Perturbations around the Eclipse Path, which was first performed during October’s annular solar eclipse. .
Each rocket will launch four soda-bottle-sized science instruments within the path of totality to measure changes in the ionosphere’s temperature, particle density, and electric and magnetic fields about 55 to 310 miles (90 to 500 kilometers) above the ground. measurement.
“Understanding the ionosphere and developing models to help us predict disturbances is critical to ensuring our increasingly communication-dependent world runs smoothly,” Barjatya said in a statement.
The sounding rockets will reach a maximum height of 260 miles (420 kilometers) during flight.
During the 2023 annular eclipse, instruments on the rockets measured immediate sharp changes in the ionosphere.
“We saw disturbances that could affect radio communications in the second and third rockets, but not during the first rocket that preceded a local eclipse,” said Barjatya. “We are very excited to relaunch them during the total eclipse, to see if the disturbances start at the same height and if their size and scale remain the same.”
Rise above the clouds
Three different experiments will be flown aboard NASA’s high-altitude research planes known as WB-57s.
The WB-57s can carry nearly 9,000 pounds (4,082 kilograms) of scientific instruments up to 60,000 to 65,000 feet (18,288 to 19,812 meters) above the Earth’s surface, making it the workhorse of NASA’s Airborne Science Program , said Peter Layshock, manager of NASA. WB-57 High Altitude Research Program at Johnson Space Center in Houston.
The advantages of using WB-57s are that a pilot and equipment operator can fly above the clouds for about 6 ½ hours without refueling within the total path of the eclipse that includes Mexico and the USA, which allows for continuous and unobstructed view. The flight path of the planes means that the instruments will be within the shadow of the moon for longer than they would be on the ground. Four minutes of totality on the ground equals six full minutes in the plane, Layshock said.
One experiment will also target the ionosphere using an instrument called an ionosonde, which acts like a radar by sending out high-frequency radio signals and listening for the echoes as they bounce off the ionosphere to measure the number of charged particles there. measurement.
The other two experiments will focus on the crown. One project will use cameras and spectrometers to reveal more details about the temperature and chemical composition of the corona, as well as capture data on large bursts of solar material from the sun known as coronal mass eruptions.
Another project, led by Amir Caspi, chief scientist at the Southwest Research Institute in Boulder, Colorado, aims to capture images of the eclipse from 50,000 feet (15,240 meters) above the Earth’s surface in the hope of spying structures and data inside. of the middle and lower crown. Using high-speed and high-resolution cameras, capable of taking images in visible light and infrared light, the experiment will also look for asteroids orbiting within sunlight.
“In the infrared, we don’t really know what we’re going to see, and that’s part of the mystery of rare observations,” Caspi said. “Each eclipse gives you a new opportunity to expand on things as you take what you learned at the last eclipse and solve a new piece of the puzzle.”
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