ephemeris time

简明释义

星历时

英英释义

例句

1.Astronomers often convert Universal Time to ephemeris time for better precision in their calculations.

天文学家通常将世界时转换为历书时间以提高计算的精度。

2.The spacecraft's navigation system uses ephemeris time to ensure accurate positioning during its mission.

航天器的导航系统使用历书时间以确保在任务期间的准确定位。

3.In astrodynamics, the accuracy of trajectory predictions heavily relies on ephemeris time data.

在天体动力学中，轨迹预测的准确性在很大程度上依赖于历书时间数据。

4.When analyzing orbital dynamics, scientists must consider ephemeris time for accurate results.

在分析轨道动力学时，科学家必须考虑历书时间以获得准确结果。

5.The satellite's position is calculated using ephemeris time, which is a precise time scale based on the motion of celestial bodies.

卫星的位置是通过使用历书时间计算的，这是一种基于天体运动的精确时间尺度。

作文

In the realm of astronomy and space exploration, precise timekeeping is essential for navigation, observation, and data collection. One of the fundamental concepts in this field is ephemeris time, which refers to a time scale that is based on the positions of celestial bodies. This concept plays a crucial role in the accurate calculation of the orbits of planets, moons, and artificial satellites. Understanding ephemeris time is vital for astronomers and space scientists as it allows them to synchronize observations and predict celestial events with high accuracy.Historically, the term ephemeris time originated from the need to track the movements of celestial objects. The word 'ephemeris' comes from the Greek word 'ephemeros,' meaning 'lasting only a day.' In astronomy, an ephemeris is a table or data set that provides the positions of astronomical objects at regular intervals. Thus, ephemeris time is intrinsically linked to these calculations, as it provides a framework for understanding how celestial bodies move over time.The development of ephemeris time was largely driven by the limitations of traditional timekeeping methods, which relied on the rotation of the Earth and its position relative to the Sun. These methods were not sufficiently precise for the needs of modern astronomy, especially when considering the vast distances and speeds involved in space travel. As a result, astronomers sought a more reliable time standard, leading to the introduction of ephemeris time as a way to measure time based on the gravitational influences of celestial bodies.One of the significant advantages of ephemeris time is its ability to account for variations in the Earth's rotation and the gravitational effects of the Moon and other planets. This makes it particularly useful for missions that require precise positioning, such as satellite launches and interplanetary travel. For instance, when planning a mission to Mars, scientists must consider the ephemeris time to ensure that the spacecraft arrives at the correct location at the right moment. Any discrepancies in timing could result in mission failure or missed opportunities for scientific observation.Moreover, ephemeris time is also essential for the synchronization of instruments used in astronomical observations. Telescopes and other observational tools must be calibrated to the ephemeris time to ensure that they are pointing at the correct target in the sky at the right time. This level of precision is necessary for capturing images and data that are critical for advancing our understanding of the universe.In conclusion, ephemeris time is a fundamental concept in astronomy that underpins many aspects of space exploration and celestial observation. Its ability to provide a precise and reliable time scale based on the positions of celestial bodies makes it indispensable for astronomers and space scientists alike. As we continue to explore the cosmos, the importance of ephemeris time will only grow, enabling us to unlock the mysteries of the universe and expand our knowledge of the celestial phenomena that surround us.

在天文学和空间探索领域，精确的时间测量对于导航、观察和数据收集至关重要。这个领域的一个基本概念是历书时间，它指的是基于天体位置的时间尺度。这个概念在准确计算行星、月球和人造卫星的轨道中发挥着关键作用。理解历书时间对天文学家和空间科学家至关重要，因为它使他们能够同步观察并高精度地预测天文事件。历史上，历书时间一词源于跟踪天体运动的需要。‘历书’这个词来自希腊语‘ephemeros’，意为‘仅持续一天’。在天文学中，历书是提供天文物体在规律间隔内位置的表格或数据集。因此，历书时间与这些计算密切相关，因为它为理解天体如何随时间移动提供了框架。历书时间的发展主要是由于传统时间测量方法的局限性，这些方法依赖于地球的自转及其相对于太阳的位置。这些方法对于现代天文学的需求不足够精确，尤其是在考虑到太空旅行涉及的巨大距离和速度时。因此，天文学家寻求一种更可靠的时间标准，导致了历书时间的引入，以便基于天体的引力影响来测量时间。历书时间的一个显著优势是它能够考虑地球自转的变化以及月球和其他行星的引力效应。这使其在需要精确定位的任务中尤为有用，例如卫星发射和行星际旅行。例如，在规划前往火星的任务时，科学家必须考虑历书时间，以确保航天器在正确的时间到达正确的位置。任何时间上的差异都可能导致任务失败或错过科学观察的机会。此外，历书时间对于天文观察中使用的仪器的同步也至关重要。望远镜和其他观察工具必须根据历书时间进行校准，以确保它们在天空中正确指向目标。这种精确程度对于捕捉图像和数据至关重要，这些数据对于推动我们对宇宙的理解至关重要。总之，历书时间是天文学中的一个基本概念，它支撑着空间探索和天文观察的许多方面。它能够基于天体位置提供精确可靠的时间尺度，使其对天文学家和空间科学家来说不可或缺。随着我们继续探索宇宙，历书时间的重要性将只会增加，使我们能够解锁宇宙的奥秘，扩展我们对周围天文现象的知识。