semi major axis

简明释义

长半径

英英释义

例句

1.The semi major axis 半长轴 of the Earth's orbit around the Sun is approximately 149.6 million kilometers.

地球围绕太阳的半长轴 semi major axis大约是1.496亿公里。

2.In orbital mechanics, the semi major axis 半长轴 is crucial for calculating the orbit period.

在轨道力学中，半长轴 semi major axis对于计算轨道周期至关重要。

3.The length of the semi major axis 半长轴 of an ellipse determines its size.

椭圆的半长轴 semi major axis的长度决定了它的大小。

4.The semi major axis 半长轴 can be calculated using the formula involving the focal distance.

可以通过涉及焦距的公式计算出半长轴 semi major axis。

5.Astronomers often use the semi major axis 半长轴 to describe the orbits of planets.

天文学家常用半长轴 semi major axis来描述行星的轨道。

作文

In the study of celestial mechanics, the concept of the semi major axis is fundamental to understanding the orbits of celestial bodies. The semi major axis refers to the longest radius of an ellipse, which is a common shape for the orbits of planets, moons, and other astronomical objects. This term is crucial because it helps astronomers calculate various orbital parameters, including the period of revolution and the distance between objects in space.To illustrate, consider the orbit of Earth around the Sun. The path that Earth follows is not a perfect circle but rather an ellipse, with the Sun at one of the focal points. The length of the semi major axis in this case is approximately 149.6 million kilometers, which is also known as an astronomical unit (AU). This measurement is significant because it provides a standard way to express distances within our solar system and beyond.Understanding the semi major axis allows scientists to predict the behavior of celestial bodies. For example, Kepler's laws of planetary motion utilize the semi major axis to describe how planets move in their orbits. According to Kepler's third law, the square of the orbital period of a planet is directly proportional to the cube of the semi major axis of its orbit. This relationship means that if we know the semi major axis, we can determine how long it takes for a planet to complete one full orbit around the Sun.The implications of the semi major axis extend beyond our solar system. Astronomers use this concept when studying exoplanets—planets that orbit stars outside our solar system. By measuring the semi major axis of these distant worlds, scientists can infer their potential habitability. For instance, a planet located within the 'Goldilocks zone,' where conditions might be just right for liquid water to exist, will have a specific semi major axis relative to its star.In addition to its importance in astronomy, the semi major axis has applications in fields such as astrodynamics and satellite communications. Satellites in geostationary orbits, for example, must maintain a specific semi major axis to remain fixed above a particular point on Earth. This requires precise calculations to ensure that the satellite can effectively communicate with ground stations without drifting out of position.In conclusion, the semi major axis is a critical parameter in the study of orbits, with significant implications for astronomy, physics, and engineering. Its role in defining the shape and size of elliptical orbits allows scientists to make predictions about the motion of celestial bodies, assess the potential for extraterrestrial life, and design effective satellite systems. As our understanding of the universe continues to grow, the semi major axis will undoubtedly remain a key concept in unraveling the mysteries of space.

在天体力学的研究中，半长轴的概念对于理解天体的轨道至关重要。半长轴指的是椭圆的最长半径，椭圆是行星、卫星和其他天文物体轨道的常见形状。这个术语非常重要，因为它帮助天文学家计算各种轨道参数，包括公转周期和空间中物体之间的距离。例如，考虑地球绕太阳的轨道。地球所遵循的路径不是一个完美的圆，而是一个椭圆，太阳位于其中一个焦点。此时的半长轴长度约为1.496亿公里，这也被称为天文单位（AU）。这个测量值很重要，因为它提供了一种标准方式来表达我们太阳系及以外的距离。理解半长轴使科学家能够预测天体的行为。例如，开普勒的行星运动定律利用半长轴来描述行星在其轨道中的运动。根据开普勒的第三定律，一个行星的公转周期的平方与其轨道的半长轴的立方成正比。这一关系意味着，如果我们知道半长轴，就可以确定一个行星完成一次完整轨道所需的时间。半长轴的影响超出了我们的太阳系。天文学家在研究系外行星（围绕太阳系外恒星运行的行星）时也使用这个概念。通过测量这些遥远世界的半长轴，科学家可以推断它们潜在的宜居性。例如，位于“适居带”内的行星，其条件可能恰好适合液态水存在，相对于其恒星将有一个特定的半长轴。除了在天文学中的重要性外，半长轴在诸如航天动力学和卫星通信等领域也有应用。例如，处于静止轨道的卫星必须保持特定的半长轴，以便固定在地球的特定位置上。这需要精确的计算，以确保卫星能够有效地与地面站进行通信，而不会偏离位置。总之，半长轴是研究轨道的重要参数，对天文学、物理学和工程学具有重要意义。它在定义椭圆轨道的形状和大小方面的作用使科学家能够对天体的运动做出预测，评估外星生命的潜力，以及设计有效的卫星系统。随着我们对宇宙理解的不断加深，半长轴无疑将继续成为揭示太空奥秘的关键概念。