On March 20, 2025, at 9:00 PM PDT in Torrance, California, Jupiter was prominently visible in the southwestern sky, situated in the constellation Taurus. The planet’s four largest moons—Io, Europa, Ganymede, and Callisto—were observable through a Celestron C11 f/10 telescope.
2025 年 3 月 20 日，太平洋夏令時晚上 9：00，加利福尼亞州托倫斯市，木星在西南天空中顯得格外可見，位於金牛座。這顆行星上最大的四顆衛星——木衛一、木衛二、木衛三和木衛四——可以通過 Celestron C11 f/10 望遠鏡觀測到。
Moon Phase and Sky Conditions
月相和天空條件
At that time, the Moon was in a waning gibbous phase, approximately 72% illuminated. It rose after sunset and was visible in the eastern sky, providing moderate illumination that could slightly affect deep-sky observations but still allowed for clear views of bright objects like Jupiter and its moons. The Nine Planets
當時，月球處於衰落凸月相 ，大約 72% 被照亮 。它在日落後升起，在東方的天空中可見，提供適中的照明，可能會略微影響深空觀測，但仍可以清晰地看到木星及其衛星等明亮天體。 九大行星
Observing Jupiter and Its Moons
觀察木星及其衛星
The Galilean moons orbit Jupiter in a relatively straight line along its equatorial plane. Their positions change noticeably over the course of a few hours due to their rapid orbits. On this particular evening, their arrangement would have been as follows (from west to east):
伽利略衛星沿赤道平面以相對直線繞木星運行。由於它們的軌道速度很快，它們的位置在幾個小時內發生了明顯的變化。在這個特定的晚上，他們的安排如下（從西到東）：
- Callisto: Farthest west of Jupiter
木衛四 ：木星最西端 - Ganymede: Closer to Jupiter on the western side
木衛三 ：靠近西側的木星 - Io: Just east of Jupiter
木衛一 ：木星以東 - Europa: Farther east of Jupiterblissphotographics.com
木衛二 ：木星 blissphotographics.com 以東更遠的地方
*Note: The exact positions can vary based on the time and the observer’s location. For precise real-time positions, you can use tools like TheSkyLive’s Galilean Moons Tracker.
*注意：確切位置可能會因時間和觀察者的位置而異。要獲得精確的即時位置，您可以使用 TheSkyLive 的 Galilean Moons Tracker 等工具。
Tips for Observing
觀察提示
- Telescope Orientation: Depending on your telescope’s optics, the view might be inverted or mirrored. For instance, Newtonian reflectors invert the image vertically, while refractors with a diagonal may mirror it horizontally.
望遠鏡方向 ：根據望遠鏡的光學元件，視圖可能是倒置或鏡像的。例如，牛頓反射鏡垂直反轉圖像，而具有對角線的折射鏡可能會水平鏡像圖像。 - Optimal Viewing: To minimize the Moon’s glare, try observing Jupiter when it’s higher in the sky and the Moon is lower on the horizon.
最佳觀看效果 ：為了盡量減少月亮的眩光，請嘗試在木星在天空中較高而月亮在地平線上較低時觀察木星。 - Recording Observations: Sketching the positions of the moons at different times can be a fun way to track their orbits and understand their motion around Jupiter.
記錄觀測結果：勾勒出衛星在不同時間的位置是跟蹤它們的軌道並了解它們圍繞木星的運動的一種有趣方式。