mean sidereal time

简明释义

平均恒星时

英英释义

例句

1.To determine the best time for observation, we need to convert local time to mean sidereal time.

为了确定最佳观察时间，我们需要将当地时间转换为恒星平时。

2.The software automatically adjusts for mean sidereal time to track satellites accurately.

该软件自动调整恒星平时，以准确跟踪卫星。

3.The telescope is aligned with the celestial coordinates using mean sidereal time as a reference.

望远镜使用恒星平时作为参考来对齐天体坐标。

4.Navigators use mean sidereal time to calculate their position at sea.

导航员使用恒星平时来计算他们在海上的位置。

5.The astronomer calculated the position of the stars based on the current mean sidereal time.

天文学家根据当前的恒星平时计算了星星的位置。

作文

Understanding the concept of mean sidereal time is essential for both astronomers and navigators. Essentially, mean sidereal time refers to the average time it takes for the Earth to rotate once on its axis relative to the distant stars. This measurement is crucial because it helps us keep track of celestial movements and ensures accurate positioning in space. Unlike solar time, which is based on the position of the sun, mean sidereal time is based on the stars' positions, making it a more precise method for astronomical observations.The importance of mean sidereal time can be traced back to ancient civilizations that relied heavily on the stars for navigation and agriculture. For instance, the Egyptians used the stars to determine the timing of their agricultural cycles, while sailors depended on the night sky to guide their journeys across the seas. As technology advanced, the need for a more standardized timekeeping method became apparent, leading to the development of mean sidereal time as a reliable reference point.In practical terms, mean sidereal time is measured in hours, minutes, and seconds, just like regular time. However, one key difference is that a sidereal day is approximately 23 hours, 56 minutes, and 4 seconds long. This slight variation is due to the Earth's orbit around the Sun; as the Earth moves along its path, it must rotate a little longer than 360 degrees to bring the Sun back to the same position in the sky. Therefore, if we were to rely solely on solar time, we would lose track of the stars' positions over time.Astronomers utilize mean sidereal time to schedule observations and predict celestial events. For example, when planning to observe a specific star or planet, they must account for the time it will take for that celestial body to rise above the horizon. By using mean sidereal time, they can accurately predict when these events will occur, ensuring that they do not miss important observations.Additionally, mean sidereal time plays a vital role in the field of satellite navigation. Global Positioning System (GPS) satellites rely on precise timing signals to provide accurate location data. These satellites use mean sidereal time to synchronize their clocks with the Earth's rotation, allowing users to determine their exact position anywhere on the planet. Without this synchronization, GPS technology would be significantly less accurate, affecting everything from personal navigation to global logistics.In conclusion, mean sidereal time is a fundamental concept that underpins many aspects of astronomy and navigation. Its significance extends beyond mere timekeeping; it is a critical tool that allows us to understand our place in the universe and navigate our world effectively. As we continue to explore the cosmos and develop new technologies, the relevance of mean sidereal time will only grow, reinforcing its importance in scientific research and everyday applications.

理解平均恒星时的概念对天文学家和导航员来说至关重要。基本上，平均恒星时指的是地球相对于遥远的恒星旋转一次轴的平均时间。这一测量方法至关重要，因为它帮助我们跟踪天体运动，并确保在空间中的准确定位。与基于太阳位置的太阳时不同，平均恒星时是基于恒星位置的，因此它是一种更精确的天文观测方法。平均恒星时的重要性可以追溯到古代文明，这些文明在导航和农业上高度依赖星星。例如，埃及人利用星星来确定农业周期的时间，而水手则依靠夜空引导他们穿越海洋。随着技术的发展，对一种更标准化的计时方法的需求变得显而易见，这导致了平均恒星时作为一个可靠的参考点的发展。在实际应用中，平均恒星时以小时、分钟和秒为单位进行测量，就像常规时间一样。然而，一个关键的区别是，恒星日大约为23小时56分钟04秒。这一微小的变化是由于地球围绕太阳的轨道运动；当地球沿着它的路径移动时，它必须比360度多旋转一点，以将太阳带回天空中的同一位置。因此，如果我们仅依靠太阳时间，我们会随着时间的推移而失去对恒星位置的追踪。天文学家利用平均恒星时安排观测和预测天文事件。例如，在计划观察特定星星或行星时，他们必须考虑该天体升出地平线所需的时间。通过使用平均恒星时，他们可以准确预测这些事件何时发生，确保他们不会错过重要的观察。此外，平均恒星时在卫星导航领域也发挥着至关重要的作用。全球定位系统（GPS）卫星依赖精确的时间信号提供准确的位置数据。这些卫星使用平均恒星时来使其时钟与地球的旋转同步，从而允许用户在地球上的任何地方确定其确切位置。如果没有这种同步，GPS技术的准确性将大大降低，影响从个人导航到全球物流的方方面面。总之，平均恒星时是一个基本概念，支撑着天文学和导航的许多方面。它的重要性超越了单纯的计时；它是一个关键工具，使我们能够理解自己在宇宙中的位置，并有效地导航我们的世界。随着我们继续探索宇宙并开发新技术，平均恒星时的相关性只会增加，进一步强化其在科学研究和日常应用中的重要性。