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June 14, 2021
These unusual natural formations were first discovered in the fields of Europe in the late 18th century. Consisting almost entirely of natural glass, they continue to attract the attention of researchers to this day. These are tektites - small solid bodies with characteristic relief forms: spheroidal, dumbbell-shaped, drop-shaped. Color - from black to green and yellowish-olive.
Image above: Tektite (Libyan glass). Dimensions 6x5x4 cm, weight 100 g, Libyan Desert. Meteorite collection of the Moscow Planetarium, No. 70.
In terms of chemical composition, they are close to obsidians, with a SiO₂ content of 70-75%, but do not contain inclusions of microcrystals, there are almost no gas bubbles and very little water. In some cases, there is an increased content of Cr, Ni, Co, Mg. Sample weights range from the first grams to several kilograms. The largest tektite weighing 3.2 kg was found in Laos.
Image above: Tektite (Indooshinite). Diameter 6 cm, weight 140 g, China. Meteorite collection of the Moscow Planetarium, no. 90.
The term tektite (from the Greek - molten) was introduced into scientific circulation by the Austrian geologist Eduard Suess at the beginning of the 20th century. He was one of the first to suggest their extraterrestrial origin. Tektites are named according to the geographical position of the finds, where they form accumulations in the sediments, without being genetically related to them: Moldavites - Czech Republic, Germany, according to the German name of the Vltava River (German Moldau); Libyan glass - Libya; Australians - Australia; Indo-Shinites - Indochina; Malayazites - Malaysia, etc.
Image above: Tektite (Moldavite). Size 5x3x1 cm, weight 19 g, Czech Republic. Meteorite collection of the Moscow Planetarium, No. 77.
The question of the origin of tektites still remains open, since no one has observed their fall to the Earth, like the fall of meteorites. Yes, and traces of their fall - craters were also not observed in the immediate vicinity of the finds. So, in the Libyan desert, where the so-called. "Libyan glass", there is not the slightest trace of any meteorite crater. Therefore, the discussion about the origin of tektites has been going on for almost 200 years.
At present, the majority of scientists admit the earthly impact hypothesis, according to which tektites are high-temperature glasses that arose when meteorites or asteroids hit the ground. Some scientists believe that tektites came to Earth from the Moon. According to another group of researchers, the most promising hypothesis for the origin of tektites is their comet delivery to Earth. Whether this is so is a topic for further research.
Source: Moscow Planetarium.
Related links:
ROSCOSMOS Press Release: https://www.roscosmos.ru/31427/
Tektites: https://www.roscosmos.ru/tag/tektitih/
Moscow Planetarium: https://www.roscosmos.ru/tag/moskovskiy-planetariy/
Images, Text, Credits: ROSCOSMOS/Moscow Planetarium/Orbiter.ch Aerospace/Roland Berga.
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