"Some of the dominant colors seen in aurorae are red, a hue produced by the nitrogen molecules, and green, which is produced by oxygen molecules." "Every type of atom or molecule, whether it's atomic hydrogen or a molecule like carbon dioxide, absorbs and radiates its own unique set of colors, which is analogous to how every human being has a unique set of fingerprints," Teets told. The bright colors of the northern lights are dictated by the chemical composition of Earth's atmosphere. "These particles are deflected towards the poles of Earth by our planet's magnetic field and interact with our atmosphere, depositing energy and causing the atmosphere to fluoresce," said astronomer Billy Teets, the director of Dyer Observatory at Vanderbilt University in Nashville, Tennessee. In the Northern Hemisphere, the phenomenon is called the northern lights (aurora borealis), while in the Southern Hemisphere, it's called the southern lights (aurora australis). When that wind slams into Earth's ionosphere, or upper atmosphere, the aurora is born. (Image credit: NASA) What are the northern lights?Īt any given moment, the sun is ejecting charged particles from its corona, or upper atmosphere, creating what's called the solar wind. A portion of the space station's solar array is visible in the top left corner of the image. At the time this photo was taken, the space station was orbiting about 258 miles (415 kilometers) above Russia and the Ukraine. The theory would eventually prove correct, but not until long after Birkeland's 1917 death.Ī lime-green aurora glows above Earth's city lights in this view from the International Space Station. Norwegian scientist Kristian Birkeland proposed that electrons emitted from sunspots produced the atmospheric lights after being guided toward the poles by Earth's magnetic field. The science behind the northern lights wasn't theorized until the turn of the 20th century. also notes the aurora, according to NASA. A royal astronomer under Babylon's King Nebuchadnezzar II inscribed his report of the phenomenon on a tablet dated to 567 B.C., for example, while a Chinese report from 193 B.C. One North American Inuit legend suggests that the northern lights are spirits playing ball with a walrus head, while the Vikings thought the phenomenon was light reflecting off the armor of the Valkyrie, the supernatural maidens who brought warriors into the afterlife.Įarly astronomers also mentioned the northern lights in their records. and is sourced from reporting by The New York Times.Since that time, civilizations around the world have marveled at the celestial phenomenon, ascribing all sorts of origin myths to the dancing lights. ![]() Weekly county case and death data prior to Jan. reporting periods that are two weeks apart, which are sometimes 13 or 15 days apart because of holidays and other disruptions to normal reporting. The 14-day change measures the difference between C.D.C. may make historical updates as more data is reported. Governments sometimes revise data or report a single-day large increase in cases or deaths without specifying when those cases and deaths occurred, which can cause an irregular pattern in the daily reported figures. Department of Health and Human Services, and it includes confirmed and suspected adult and pediatric patients. Hospitalization data is reported by individual hospitals to the U.S. ![]() Population and demographic data is from the U.S. Iowa provides incomplete negative test result data, affecting the accuracy of test positivity rates.ĭata on this page is reported by the Centers for Disease Control and Prevention. Iowa no longer reports aggregate case and death data to the C.D.C. reported no cases or deaths for Oregon in its weekly update because the state did not report new data. reported no cases or deaths for Mississippi in its weekly update because the state did not report new data. reported no cases or deaths for Indiana in its weekly update because the state did not report new data.
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