Glossary term: 로시한계
Description: 조석력은 천체를 길쭉한 모양으로 늘어나게 하는 역할을 합니다. 예를 들어, 달은 지구의 바다에 작용하여 물이 두 곳에서 부풀어 오르게 만들고, 이로 인해 조석(밀물과 썰물) 현상이 생깁니다.
두 개의 큰 천체는 서로에게 조석력을 주고받습니다. 물체가 클수록, 그리고 서로 가까울수록, 그 조석력은 더 강해집니다. 조석력이 너무 강하면, 작은 천체가 찢어질 정도로 커질 수도 있습니다.
특정 질량과 크기를 가진 물체(예: 소행성이나 달)가 다른 거대한 천체에 너무 가까워지면, 그 조석력에 의해 찢어질 수 있는 한계 거리가 있습니다. 이 거리를 로시한계라고 합니다. 로시한계의 대표적인 예는 거대 행성을 도는 위성에서 볼 수 있습니다. 만약 위성이로시 한계보다 행성에 더 가까워지면, 조석력 때문에 부서져 버리고, 그 조각들이 모여 거대 행성의 고리를 형성하게 됩니다.
또한 달이나 다른 암석형 천체의 표면에 보이는 ‘카테네(catenae)’, 즉 분화구가 줄지어 있는 구조는 소행성이 로시 한계를 지나며 부서져 여러 조각으로 나뉘어 충돌한 결과로 여겨집니다.
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
- 아랍어: حد روش
- 독일어: Roche-Grenze
- 영어: Roche Limit
- 프랑스어: Limite de Roche
- 이탈리아어: Limite di Roche
- 일본어: ロッシュ限界 (external link)
- 브라질 포르투갈어: Limite de Roche
- 중국어 간체: 洛希极限
- 중국어 번체: 洛希極限
Related Media
Comet Shoemaker-Levy After Crossing Jupiter's Roche Limit
Caption: This panoramic image captured by the Hubble Space Telescope shows fragments of Comet Shoemaker–Levy 9. This comet was discovered in 1993 as the series of fragments you see here. These fragments were orbiting Jupiter. It is thought that at some point in the previous few decades the whole, unfragmented comet had been gravitationally captured by Jupiter. Then in 1992 the comet passed within Jupiter’s Roche limit.
Astronomical objects exert gravitational forces on each other. The closer one is to an object, the larger the force. As astronomical objects have a real physical size, the side of an object closer to another object will feel a stronger gravitational force from that other object than the more distant side. The gravitational stretching distorts the object. This gravitational stretching force is known as the tidal force. When an object is close enough to a large body like Jupiter, the object will feel such a large tidal stretching force that it will overcome the internal gravitational force holding the object together, ripping it to shreds. The distance from the larger body within which this occurs is known as the Roche limit.
When Shoemaker–Levy 9 crossed Jupiter's Roche limit in 1992, the tidal force pulled the comet into separate fragments. Here we see these fragments in a chain as they orbited Jupiter in May 1994. Later in July 1994 the comet fragment plunged into Jupiter’s atmosphere over the course of a week in a spectacular series of impacts. This event provided scientists with a rare opportunity to witness an impact unfolding in real time.
Credit: NASA, ESA, and H. Weaver and E. Smith (STScI)
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License: PD Public Domain icons
