Glossary term: 伽利略衛星

Description: 伽利略衛星是圍繞木星運行的四顆最大、最明亮的衛星：木衛一（Io, 艾奧）、木衛二（Europa, 歐羅巴）、木衛三（Ganymede, 加尼美得）和木衛四（Callisto, 卡利斯托）。離木星最近的是木衛一，它有數百座活火山。木衛一火山爆發的主要原因是受到木星引力潮汐效應的 "揉捏"。木衛二的整個表面都被冰覆蓋著。據信，冰層下是液態水海洋，是太陽系除地球外能夠孕育生命的最佳候選者之一。木衛三是太陽系中體積最大的衛星，也是質量最大的，是月球質量的兩倍。木衛四的大小幾乎與水星完全一致，但質量只有水星的三分之一。

這四顆伽利略衛星是伽利略-伽利萊（Galileo Galilei）於 1610 年發現的，是伽利萊使用望遠鏡進行天文觀測的開創性活動中的若干發現之一。伽利萊通過記錄發現，隨著時間的推移，四顆衛星圍繞木星運行，就像一個微型太陽系。這清楚地表明，天體可以圍繞地球以外的中心運行；這一觀測結果在科學界對太陽系的認知轉變過程中發揮了重要作用，從以地球為中心（地心說）轉為以太陽為中心（日心說）。

Related Terms:

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

This is an automated transliteration of the simplified Chinese translation of this term

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".

Related Media

木星的自轉，作者 Vishal Sharma，印度

Caption: 2021 年國際天文學聯合會 (IAU) 天文教育辦公室 (OAE) 天體攝影比賽，伽利略衛星類第三名：《木星的自轉》，作者 Vishal Sharma，來自印度。這幅延時攝影作品精美地展示了木星的自轉，以及畫面右側經過的兩顆伽利略衛星。木星自轉一圈只需不到 10 個小時，我們可以看到大紅斑從左向右移動。在這短短的時間內，兩顆衛星明顯沿著它們的軌道前進了一段距離。這張照片是 2020 年在印度北部拍攝的。
Credit: Vishal Sharma/IAU OAE

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

The planet Jupiter, seen here as a bright disk, is orbited by the four Galilean moons, seen here as bright dots

Jupiter Moons Movie2, by Nicolas Hurez, Paul-Antoine Matrangolo, and Carl Pennypacker, United States of America

Caption: 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).
Credit: Nicolas Hurez, Paul-Antoine Matrangolo and Carl Pennypacker/IAU OAE

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

Jupiter with coloured horizontal bands of clouds. The shadow of the moon Io is seen as a dark circle in the top left

Jupiter, Io and its shadow, by Ralf Burkart, Germany

Caption: 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.
Credit: Ralf Burkart/IAU OAE

License: CC-BY-4.0 Creative Commons 姓名標示 4.0 國際 (CC BY 4.0) icons

伊奧衛星

Caption: 美國國家航空航天局的伽利略號航天器於1999年7月3日獲得了木星衛星木衛一的最高分辨率圖像。木衛一是伽利略-伽利雷 1610 年發現的四顆衛星之一。木衛一的顏色源於硫化物，是大量火山活動存在的證據。木星和鄰近衛星的潮汐力是木衛一火山活動的原因。
Credit: 美國宇航局/JPL/亞利桑那大學 credit link

License: PD Public Domain icons

Europa

Caption: This image taken by NASA's Galileo space probe in September 1996 shows Jupiter's ice-covered satellite, Europa, in approximate natural color. Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth's moon.
Credit: NASA/JPL/DLR

License: PD Public Domain icons

You may also be interested in

The Office of Astronomy for Education is hosted by the Haus der Astronomie on the campus of the Max Planck Institute for Astronomy in Heidelberg. The Office of Astronomy for Education is an office of the International Astronomical Union, with substantial funding from the Klaus Tschira Foundation and the Carl Zeiss Foundation. The Shaw-IAU Workshops on Astronomy for Education
are funded by the Shaw Prize Foundation.