The Kamchatka meteor was a

meteor A meteoroid () is a small rocky or metallic body in outer space. Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as micr ...

that exploded in an

air burst An air burst or airburst is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target. The principal military advantage of an air burst over ...

off the east coast of the

Kamchatka Peninsula The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and we ...

in eastern

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

on 18 December 2018. At around midday, local time, an asteroid roughly 10 meters in diameter entered the atmosphere at a speed of , with a

TNT equivalent TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a m ...

energy of 173 kilotons, more than 10 times the energy of the

Little Boy "Little Boy" was the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II, making it the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress ''Enola Gay'' p ...

bomb dropped on

Hiroshima is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui h ...

in 1945. The object entered at a steep angle of 7 degrees, close to the

zenith The zenith (, ) is an imaginary point directly "above" a particular location, on the celestial sphere. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" ...

, terminating in an air burst at an altitude of around .

Overview

Based on the energy and velocity of the impact, the asteroid had a mass of 1600

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

s and a diameter of between 10 and 14 meters (32 to 45 feet) depending on its density. The impact was announced around 8 March 2019, and is the largest asteroid to impact Earth since the 20-meter

Chelyabinsk meteor The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural (region), Ural region in Russia on 15 February 2013 at about 09:20 Yekaterinburg Time, YEKT (03:20 Coordinated Universal Time, UTC). It was caused ...

's entry in February 2013, and the third largest recorded meteor since 1900 after that and the

Tunguska event The Tunguska event (occasionally also called the Tunguska incident) was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of June 30, ...

. NASA's

Terra satellite Terra (EOS AM-1) is a multi-national, NASA scientific research satellite in a Sun-synchronous orbit around the Earth that takes simultaneous measurements of Earth's atmosphere, land, and water to understand how Earth is changing and to identify ...

and the Japanese Meteorological Agency's

Himawari 8 is a Japanese weather satellite, the 8th of the Himawari geostationary weather satellites operated by the Japan Meteorological Agency. The spacecraft was constructed by Mitsubishi Electric with assistance from Boeing, and is the first of two ...

recorded the dust trail from the event, although their observation interval was too long to image the air burst itself. The dominant period of the

CTBTO The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization, or CTBTO Preparatory Commission, is an international organization based in Vienna, Austria, that is tasked with building up the verification regime of the Co ...

infrasound was very long, on the order of 20 to 25 seconds, corresponding to energy on the order of 100 to 200 kilotons. The

shockwave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

was strong enough to have cracked windows had the shockwave been over a built-up region. Even though it was only six years after the previous one, events as large as this are statistically estimated to occur only once every few decades on average. As of January 2017, over 723,000 asteroids were being tracked in the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

, with more discovered,

lost Lost may refer to getting lost, or to: Geography *Lost, Aberdeenshire, a hamlet in Scotland * Lake Okeechobee Scenic Trail, or LOST, a hiking and cycling trail in Florida, US History *Abbreviation of lost work, any work which is known to have bee ...

and recovered daily. Since 2011, on average, 80 new minor planets of diameter 30–50 meters or more are discovered each day. As of March 2019, 724 (roughly one in a thousand) are classified as

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

s (PHA). Neither the Chelyabinsk nor the Kamchatka meteors were on the list and would have been too small to detect with current resources.

References

{{2019 in space Modern Earth impact events Meteoroids 2018 in space 2019 in science History of the Kamchatka Peninsula December 2018 events in Russia