Meteor showers like the Quadrantids are best known for lighting up the skies and putting on spectacular shows for stargazers, but recent research suggests that they could also be responsible for a decades-old mystery involving missing electrons in Earth’s atmosphere.
During a presentation at the annual meeting of the American Geophysical Union last December, MIT atmospheric scientist Dr. Earle Williams and his colleagues explained that they had found evidence suggesting that dust from passing meteors were absorbing electrons located high in the atmosphere, according to Tech Times and the Daily Mail.
This results in the creation of an insulating region that is low in electrons, and which radio waves can bounce off of, known as a “D-region ledge,” the study authors added. Their work could solve the long-standing puzzle of what causes sudden, drastic changes in the electrical properties of the ionosphere, and it could lead to a better understanding of the D-region ledge itself.
The electrons in our atmosphere are produced when ultraviolet light, X-rays, and other types of high-energy radiation come into contact with nitric oxide atoms, removing the negative particles and turning those atoms into ions. However, in the 1960s, scientists discovered the drastic drop in electron concentration at an altitude of about 52 miles above the Earth’s surface.
How the ‘most dramatic’ part of the atmosphere forms
This sudden decrease was discovered when rockets were sent into the upper atmosphere as part of a mission to measure electron density, among other things. The root cause of this phenomenon remained a mystery over the past 50 years, however, until the MIT-led team found that an undetectable layer of meteor dust could be to blame.
As meteors pass through a portion of the upper atmosphere called the sodium layer, they become heated through interactions with molecules of nitrogen and oxygen. The space rocks then collide with other atoms as they continue traveling through the atmosphere, ultimately reaching boiling point and leaving behind dust that is vaporized through a process known as ablation.
When this occurs, the dust left behind bind to free electrons in the atmosphere, Williams and his colleagues explained. The D-region ledge is likely more eminent at night because the sun’s UV rays are 100 times stronger during the daytime, meaning that a greater amount of free electrons are produced at this time, diminishing the region’s effect.
The researchers calculate that space rocks less than one millimeter in size traveling at speeds of approximately 33,500 miles per hour would achieve the temperature required to bond with those free electrons at an altitude of 52 miles, generating a steady supply of dust that winds up forming the D-region ledge, which Williams calls “the most dramatic gradient” of the ionosphere.
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Feature Image: Diana Robinson/Flickr
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