The northern lights of Earth are more than just dazzling light shows — they also generate their own strange applause too, a new study reveals.
The same energetic particles that create the dancing, dazzling northern lights high up in Earth's atmosphere also produce strange "clapping" noises just 230 feet (70 meters) from the ground, researchers said.
The results vindicate folktales and reports by wilderness travelers, which have long described sounds associated with the northern lights (which are also known as the aurora borealis).
"In the past, researchers thought that the aurora borealis was too far away for people to hear the sounds it made," Unto Laine, from Aalto University in Finland, said in a statement released today (July 9).
"This is true," Laine added. "However, our research proves that the source of the sounds that are associated with the aurora borealis we see is likely caused by the same energetic particles from the sun that create the northern lights far away in the sky. These particles or the geomagnetic disturbance produced by them seem to create sound much closer to the ground."
Laine and his colleagues determined the location of the clapping noise by comparing sounds captured by three microphones set up at a site with high auroral activity. Simultaneous measurements made by the Finnish Meteorological Institute showed a typical pattern of northern lights episodes at the time, researchers said.
Aurora sounds don't occur during every northern lights outburst, and they're usually brief and faint, requiring careful listening and a minimum of background noise to be heard.
Scientists still aren't sure exactly how the auroral sounds are created. They can be quite variable, ranging from claps and crackles to muffled bangs and sputtering sounds. Because of this sonic diversity, several different mechanisms might be at work, researchers said.
Auroras have captivated skywatchers for thousands of years. They result when charged particles from the sun collide with molecules in Earth's atmosphere, generating a glow. Earth's magnetic field lines funnel these particles over the planet's poles, causing the northern lights in the Northern Hemisphere and the southern lights, or aurora australis, in the south.
The new study will be published in the proceedings of the 19th International Congress on Sound and Vibration, a conference that's meeting in Vilnius, Lithuania from July 8 through July 12.
Editor's note: If you have an amazing northern lights photo you'd like to share for a possible story or image gallery, please contact managing editor Tariq Malik at email@example.com.
- Northern Lights Make Strange Clapping Sound | Video
- Amazing Northern Lights Pictures from June 2012
- Aurora Guide: How the Northern Lights Work (Infographic)
The Father Of Radio
Italian inventor Guglielmo Marconi received U.S. patent number No. 586,193 for his wireless telegraph on July 13, 1897. Credited as the inventor of the radio, Marconi would go on to develop this into a device that would change communication forever.
Get Ready For Your Close-Up, Mars
NASA's space probe Mariner 4 sent back the very first close-up photo of Mars on July 14, 1965. Orbiting 10,500 miles from the Red Planet, the photos revealed that there were craters on Mars.
On July 10, 1908 Dutch physicist Kamerlingh Onnes (1853-1926) made a chemical breakthrough when he liquified helium by bringing it to a temperature of 4.2 K (about -269 ºC). At the time, this was the coldest temperature reached on Earth. Today, liquid helium is used as a coolant for the superconducting magnets found in MRI machines.
Hughes' Historic Flight
Famous aviator and business magnate Howard Hughes set a new record on July 10, 1938, when he flew around the world in only 91 hours. Departing from and arriving in New York City, Hughes' Lockheed Super Electra flew him right into the annals of aviation history.
The discovery of Nobelium, element 102, was announced by physicists at the Nobel Institute in Sweden on July 9, 1957. Named after Alfred Nobel, the synthesized element still remains largely mysterious to scientists.
The 'Genesis Planet' was discovered on July 10, 2003. The planet, named PSR B1620-26 b (but also nicknamed 'Methuselah') is 12,400 light-years away from Earth, located in the constellation Scorpius. Believed to be about 12.7 billion years old, it is the oldest known extrasolar planet.
On July 11, 1811, famous Italian physicist Amedeo Avogadro published seminal essays on his molecular theory of gases. Although his ideas weren't accepted by the scientific community at the time, he has been acknowledged as an important figure in physics and chemistry. You may know him as the namesake of Avogadro's number, learned in elementary chemistry classes as 6.022 x 10^23, the number of particles in 1 mole of a substance.
Skylab Ignites A Commotion
The first U.S. space station reentered Earth's atmosphere with a bang on July 11, 1979. Skylab, which had been in orbit since 1973, created an international media event when it burned (unmanned) through the atmosphere over Western Australia. Several newspapers even offered prizes to people who found falling debris.
On July 9, 1595, the German astronomer Johannes Kepler (1571-1630) published his<em> Mysterium cosmographicum</em>, or Mystery of the Cosmos. In it, Kepler described what he thought was an invisible underlying geometric structure that explained the relationships of the planets. Although his calculations were very accurate, his theory was later proven wrong.
Swedish chemist Alfred Nobel (1833-1896) demonstrated his new invention, dynamite, on July 14, 1867 at a quarry in Surrey, England. Nobel used nitroglycerin to produce an explosive that was contained and manageable. However, concerned with his posthumous reputation as the father of dangerous explosives, Nobel arranged his famous prize to be awarded to advancements in esteemed subject areas each year.