(Image credit: Daniele Boffelli) Northern lights, southern lights and STEVE Hours of patience by photographer Daniele Boffelli resulted in this image that captures both clouds and auroras in the night sky. The auroras are best seen during the winter, when nights are long. While there, the spacecraft will collect information that could reveal more about the northern lights.

In 2018, the space agency launched the Parker Solar Probe, which is currently orbiting the sun and will eventually get close enough to 'touch' the corona. NASA is also on the hunt for clues about how the northern lights work. Alfvén waves are low-frequency yet powerful undulations that occur in plasma due to electromagnetic forces the electrons that create the northern lights 'surf' along these waves in Earth's atmosphere, accelerating rapidly. For example, researchers weren't entirely sure how the energized particles in the solar wind get accelerated to their extraordinary speeds (45 million mph) until June 2021, when a study published in the journal Nature Communications confirmed that a phenomenon called Alfvén waves gave the particles a boost. National Oceanic and Atmospheric Administration (NOAA), placing the next one in approximately 2025.ĭespite plenty of advances in heliophysics and atmospheric science, much about the northern lights remains a mystery. The last solar maximum, or period of peak activity, occurred in 2014, according to the U.S. This is when the northern lights are at their brightest and most frequent. Sometimes there's a lull, but other times, there are vast storms that bombard Earth with extreme amounts of energy. While solar wind is constant, the sun's emissions go through a roughly 11-year cycle of activity. '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. Related: Aurora colors: What causes them and why do they vary? 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. Related: Aurora myths, legends and misconceptionsĮarly astronomers also mentioned the northern lights in their records. 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. Since that time, civilizations around the world have marveled at the celestial phenomenon, ascribing all sorts of origin myths to the dancing lights.

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