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Comet Shoemaker-Levy After Crossing Jupiter's Roche Limit
صورة
الشرح: 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. Astronomical objects have a real physical size and thus the gravitational force exerted on the object will vary across the object, 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.
المصدر: NASA, ESA, and H. Weaver and E. Smith (STScI)
رابط المصدر
مصطلحات المعجم:
حد روش , قوة المد والجزر
الترخيص: الملكية العامة الملكية العامة أيقونات
ملف
( صورة
507.00 kB)
Jupiter, Io and its shadow, by Ralf Burkart, Germany
فيديو
أُنشئ لصالح OAE
الشرح: First place in the 2021 IAU OAE Astrophotography Contest, category Galilean moons.
This time-lapse of Jupiter taken in 2017 from Germany beautifully illustrates the transit of one of the Galilean moons, Io, in front of Jupiter. As this is simply a moon casting a shadow on a planet it is equivalent to a lunar eclipse on Earth observed from further away. While the shadow of the moon is clearly visible from the beginning, it might be difficult to spot the moon itself against the background of the beautiful atmospheric bands of Jupiter the first time the video is seen. Watching it repeatedly allows appreciating the rapid motion and rotation in this fantastic observation.
المصدر: Ralf Burkart/IAU OAE
مصطلحات المعجم:
أقمار غاليليو , عملاق غازي , آيو , المشتري , الأقمار , المدار , الكواكب الخارجية , الكوكب , العبور
فئات:
النظام الشمسي
الترخيص: المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات
هذا الملف على Zenodo ( فيديو 12.64 MB)
Jupiter Moons Movie2, by Nicolas Hurez, Paul-Antoine Matrangolo, and Carl Pennypacker, United States of America
فيديو
أُنشئ لصالح OAE
الشرح: Second place in the 2021 IAU OAE Astrophotography Contest, category Galilean moons.
This sequence shows the orbit of the four Galilean moons around the planet Jupiter. Almost two entire orbits of the innermost moon, Io, can be seen, with the other moons (Europa and Ganymede, but in particular Callisto) being further away, orbiting noticeably slower. The images were obtained in 2018 with the Las Cumbres Global Observatory at different locations on Earth, allowing a continuous sequence of images over approximately half a week without gaps during the day. With clear skies and over the course of several nights, the motion of the Galilean moons can also be observed with binoculars (ideally steady your elbows on a surface).
المصدر: Nicolas Hurez, Paul-Antoine Matrangolo and Carl Pennypacker/IAU OAE
مصطلحات المعجم:
أقمار غاليليو , عملاق غازي , آيو , المشتري , الأقمار , المدار , الكواكب الخارجية , الكوكب
فئات:
النظام الشمسي
الترخيص: المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) المشاع الإبداعي نَسب المُصنَّف 4.0 دولي (CC BY 4.0) أيقونات
هذا الملف على Zenodo ( فيديو 890.47 kB)
