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The theme increased in popularity from the 1950s onward, possibly as a result of nuclear anxiety following World War II, [4] and received additional boosts in popularity in 1980 with the publication of the Alvarez hypothesis, which states that the extinction of the dinosaurs 65 million years ago was caused by an asteroid impact that created the ...
[4] [6] It gained prominence following the publication of Russian science fiction writer Alexander Kazantsev's 1946 short story "Explosion"; [4] [5] [7] inspired by the similarities between the event and the nuclear bombing of Hiroshima, Kazantsev's story posits that a nuclear explosion in the engine of a spacecraft was responsible.
Bulk properties of the comet dust such as density as well as the chemical composition can distinguish between the models. For example, the isotopic ratios of comet and of interstellar dust are very similar, indicating a common origin. The 1) interstellar model says that ices formed on dust grains in the dense cloud that preceded the Sun. The ...
At 1 AU meteoroids bigger than 1 mm in size are in a collisional steady state. The significant excess of smaller meteoroids is due to the input from comets. Models of the interplanetary dust environment of the Earth result in 80-90% of cometary dust vs. only 10-20% of asteroidal dust.
The asteroid and comet belts orbit the Sun from the inner rocky planets into outer parts of the Solar System, interstellar space. [16] [17] [18] An astronomical unit, or AU, is the distance from Earth to the Sun, which is approximately 150 billion meters (93 million miles). [19] Small Solar System objects are classified by their orbits: [20] [21]
Since some aubrites contain chondritic xenoliths, it is likely that the aubrite parent body collided with an asteroid of "F-chondritic" composition. Comparisons of aubrite spectra to the spectra of asteroids have revealed striking similarities between the aubrite group and the E-type asteroids of the Nysa family.
Traditionally, small bodies orbiting the Sun were classified as comets, asteroids, or meteoroids, with anything smaller than one meter across being called a meteoroid. The term asteroid, never officially defined, [11] can be informally used to mean "an irregularly shaped rocky body orbiting the Sun that does not qualify as a planet or a dwarf ...
The Taurids are an annual meteor shower, associated with the comet Encke.The Taurids are actually two separate showers, with a Southern and a Northern component. The Southern Taurids originated from Comet Encke, while the Northern Taurids originated from the asteroid 2004 TG 10, possibly a large fragment of Encke due to its similar orbital parameters.