Glossary term: Núcleo cometário
Description: O núcleo de um cometa é a parte central do cometa. Trata-se de um objeto sólido, semelhante a uma bola de neve suja, composto por gelo e partículas rochosas e empoeiradas. Longe do Sol, o núcleo é o único componente do cometa. Quando se aproxima do Sol, o núcleo do cometa é aquecido pela luz solar. Isso faz com que o gelo da superfície sublime. O gelo sublimado e a poeira incrustada nele são ejetados passam a envolver o núcleo como uma coma com uma cauda apontando para longe do Sol.
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See this term in other languages
Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
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In Other Languages
- Árabe: نواة المذنب
- Alemão: Kometenkern
- Inglês: Comet Nucleus
- Espanhol: Núcleo del cometa
- Francês: Noyau de la comète
- Italiano: Nucleo della cometa
- Coreano: 혜성핵
- Chinês Simplificado: 彗核
- Chinês Tradicional: 彗核
Related Media
Cometa 67P/Churyumov-Gerasimenko
Caption: O núcleo do cometa 67P/Churyumov–Gerasimenko é uma “bola de neve suja” composta por uma mistura de materiais congelados e poeira. Ele tem a forma de dois grandes lóbulos: um com 4,1 km × 3,3 km × 1,8 km e outro com 2,6 km × 2,3 km × 1,8 km. Esses lóbulos estão ligados por uma pequena ponte. Quando um núcleo cometário como este se aproxima do Sol, seu material congelado é aquecido, transformando-se em gás. Isso, combinado com a poeira incorporada, fornece o material para a coma e a cauda características do cometa.
Credit: ESA/Rosetta/NAVCAM
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License: CC-BY-SA-3.0-IGO Creative Commons Attribution-ShareAlike 3.0 IGO icons
An Encounter With Halley's Comet
Caption: This image shows the solid core, or nucleus, of Halley’s Comet, captured in 1986 by the European Space Agency spacecraft Giotto during its flyby of the comet in the inner Solar System. The nucleus appears irregular and potato-shaped, measuring roughly 15 kilometers (about 9 miles) across, and is composed of a mixture of ice, dust, and rock. Unlike the glowing fuzzy cloud (coma) and long tail that make comets visible from Earth, the nucleus itself is dark and difficult to see until a spacecraft passes close enough to take detailed images.
Halley’s Comet is one of the best-known comets because it returns to the inner Solar System approximately every 76 years, allowing generations of astronomers to observe it repeatedly. The material that is released from the nucleus as the comet warms near the Sun forms a glowing coma and long tails of gas and dust, and over many returns leaves trails of debris that produce meteor showers on Earth, such as the Eta Aquarids in May and the Orionids in October.
Credit: NASA/ESA/Giotto Project
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License: PD Public Domain icons
