nucleus
Quick Summary
The nucleus of a comet is a small, solid body, typically only a few kilometers in diameter. It is composed of roughly equal parts of volatile ices, fine silicate dust, and organic materials. The primary ice is water ice, but carbon monoxide, carbon dioxide, formaldehyde, and methanol are also present. These materials formed in the solar nebula about 4.56 billion years ago through the collision and sticking of dust and ice particles.1
When a comet approaches the Sun, the ices on its surface sublimate, turning directly from solid to gas. This process releases gas molecules and embedded dust particles, forming the comet's atmosphere, known as the coma. Due to the weak gravity of the nucleus, this atmosphere expands freely into space. As the comet ages and makes repeated passes near the Sun, a layer of nonvolatile dust can accumulate on the surface, insulating the ice below and preventing further sublimation.123
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cometGeneral considerations…of four visible parts: the nucleus, the coma, the ion tail, and the dust tail. The nucleus is a solid body typically a few kilometres in diameter and made up of a mixture of volatile ices (predominantly water ice) and silicate and organic dust particles. The coma is the freely…
Read More…of four visible parts: the nucleus, the coma, the ion tail, and the dust tail. The nucleus is a solid body typically a few kilometres in diameter and made up of a mixture of volatile ices (predominantly water ice) and silicate and organic dust particles. The coma is the freely…
Read More- cometThe modern era
…and suggested that the cometary nucleus was a solid body made up of volatile ices and meteoritic material. That was called the “icy conglomerate” model but also became more popularly known as the “dirty snowball.”
Read More…and suggested that the cometary nucleus was a solid body made up of volatile ices and meteoritic material. That was called the “icy conglomerate” model but also became more popularly known as the “dirty snowball.”
Read More