The National Museum of Nature and Science of Japan reported that the object, which was seen in the sky over Tokyo at the beginning of the month, turned out to be a meteorite. He fell in a neighboring prefecture, split into two parts.
On June 2, Tokyo residents noticed a bright ball in the sky. He flew over the city and then disappeared, after which people heard a strong clap, which some took for the explosion. The ball turned out to be a meteorite that fell in Narasino, 30 kilometers from the capital. The fragments were discovered by a resident of the city near her home. Upon learning of the incident in Tokyo, she saved it, thinking that it could be part of a meteorite.
【速報✨ #火球 が隕石であることを確認‼️】
７月２日未明に各地で観測された火球（の一部）は #国立科学博物館 が分析し、隕石であることを確認💡
— かはく【国立科学博物館公式】 (@museum_kahaku) July 13, 2020
Then they were transferred for study to the National Museum of Nature and Science. Experts analyzed them and discovered isotopes of aluminum, sodium, and manganese that remained after the bombardment by cosmic rays. Since some isotopes have a half-life of only a few days, scientists were able to confirm that the stones were parts of a recently fallen meteorite. They reported the results of the analysis on the official Twitter page.
Initially, the object had a diameter of several centimeters but cracked during the impact. Fragments weigh 63 and 70 grams, respectively. The large fragment became brown: the metal contained in it rusted from the rain. Calculations showed that initially, a meteoroid with a diameter of 1.6 meters and a weight of 5.5 tons passed through the atmosphere. According to the Japanese network SonotaCo, the body entered the dense layers of the Earth’s gas shell at a speed of 15 kilometers per second. The energy of the explosion was 150 tons of TNT.
The museum plans to register the find, called “Narasino”, in the Meteorite Society. If accepted, it will be the 53rd meteorite seen in Japan. The latest known cases were recorded in 2018 when a splinter fell on a private house in the city of Komaki, and a year earlier. Then astronomers found out that the meteorite, the fall of which the Japanese observed in April 2017, turned out to be part of the giant asteroid 2003 YT1.
The noise that was heard in Tokyo during the fall of a meteorite is a rather rare occurrence. Usually, this happens if the body was very bright and exploded low enough above the Earth (approximately at an altitude of 50 kilometers). The National Astronomical Observatory of Japan reported that people rarely hear something, although on average, experts observe several fireballs every month. According to the American Meteorite Society, several thousand meteor bodies are found in the Earth’s atmosphere every day. Most of them do not notice since these bodies burn out during the day, and fragments often fall into the ocean or uninhabited territories.