Astronomers from Novosibirsk State University have for the first time in Russia captured Mercury's sodium tail, resembling a comet's tail.
According to the Vega Observatory of NSU, the rare astronomical phenomenon was captured using a special filter that highlights the spectral region of maximum tail brightness. Its length in the image is about 150,000 kilometers. The next similar observation in Russian latitudes is possible in the spring of 2027.
The mechanism of tail formation is similar to the processes in comets. Mercury's rarefied atmosphere, consisting of helium, sodium, hydrogen, potassium, and oxygen, gradually loses atoms under the influence of the solar wind, which form a luminous trail. The tail is most pronounced in the sodium spectrum at a wavelength of 589 nanometers.
The phenomenon was discovered by astronomers in 2001. There are fewer than 20 images of it in the world, NSU noted.
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