VOA科学技术2024--NASA Seeks New Discoveries During Total Solar Eclipse（在线收听）

NASA Seeks New Discoveries During Total Solar Eclipse

　　Scientists plan to closely study next week's total solar eclipse to learn new things about the sun and our own planet.

　　The eclipse can be seen on April 8 across most of North America and parts of the Atlantic and Pacific Oceans. The event will cause the moon to completely block out sunlight for up to four minutes and 28 seconds in a narrower area. Millions of people are expected to fully experience the eclipse within the so-called path of totality, where there will be a brief, total blockage of the sun.

　　The event gives scientists an unusual chance to study the sun and learn how Earth's atmosphere reacts during a total solar eclipse. So, the American space agency NASA will launch several observation projects.

　　"Scientists have long used solar eclipses to make scientific discoveries," said Kelly Korreck. She is a program scientist at NASA Headquarters in Washington, D.C. Korreck said among past discoveries were the first identification of helium and details about the sun's influence on Earth's upper atmosphere.

　　Scientists will center a lot of their efforts on the sun's outermost atmosphere, known as the corona. Cameras and instruments will closely examine the corona, which is normally hard to observe because of the brightness of the sun.

　　NASA's WB-57 research airplanes can make these observations. The jets can operate 15,000 meters or more above Earth's surface. The aircraft will help search for "new details of structures in the middle and lower corona," a NASA statement said.

　　The space agency noted that studies of the corona can provide new information about how solar activity influences Earth. Images taken during the eclipse might also help astronomers learn more about dust rings around the sun and help them find unknown asteroids orbiting near the sun.

　　NASA will be flying WB-57 planes equipped with cameras and instruments along the eclipse path. These aircraft will look for increases in charged particle flows, called plasma, and other solar materials from the corona.

　　Another project will involve the agency's "sounding rockets." The rockets are designed to make short trips while collecting data and completing scientific experiments.

　　NASA said it plans to launch three sounding rockets during the total solar eclipse. The rockets to be launched from Virginia will examine possible changes within the ionosphere, an electrically charged part of the atmosphere near the edge of space.

　　The rockets will launch at different periods "to study how the sudden drop in sunlight affects our upper atmosphere." The first rocket will blast off 45 minutes before totality happens. The second will be sent during the height of the eclipse, and the third will launch 45 minutes after.

　　Each rocket will deploy four small instruments built to measure changes in electric and magnetic fields, density, and temperature. NASA said these experiments will aim "to measure just how widespread the effects of an eclipse are."

　　NASA and other research groups will receive help from many "citizen scientists" carrying out their own observations. These individuals will take pictures of the sun's corona during different parts, or stages, of the eclipse.

　　Citizen scientists will observe the behaviors of birds and other animals as darkness arrives in the middle of the day. They will also measure dropping temperatures, observe clouds and use ham radios to test international communication signals.

　　College students will launch more than 600 weather balloons along the path of totality. The balloons are designed to identify atmospheric changes as they happen.

　　In addition to those efforts, three U.S. radar stations are in the path of the upcoming total solar eclipse. The stations – which are normally used to observe space weather – will attempt to measure changes in the upper atmosphere when the sky goes dark.

　　Research activities have been carried out during past total solar eclipses. But this time, scientists note that the moon is closer to Earth, meaning April's event will result in a longer period of darkness and a wider path of totality.

　　NASA's Korreck said this fact has researchers very interested in the science results. "Any time we can observe for longer, that gives scientists more data," she said.

　　Words in This Story

　　asteroid – n. a rocky object that goes around the sun like a planet

　　ham radio – n. a radio built by someone whose hobby is to send and receive radio messages over long distances