Does the Webb telescope stand still near L2?
在L2附近，韦布望远镜停着不动吗？
介绍韦布空间望远镜时，人们常说它位于L2附近，离地球约一百五十万公里。
Webb is often described as being near L2, about 1.5 million kilometers from Earth.
这个听起来像地址的名字，容易让人以为那里有一个让它静止的停车位。
That address-like name can suggest a parking spot where it stays still.
实际上，韦布一直在运动，L2也不是太空里的一块地面。
In reality, Webb keeps moving, and L2 is not a patch of ground in space.
这里的L2指太阳和地球共同影响下的一个特殊位置。
Here L2 refers to a special position under the combined influence of the Sun and Earth.
韦布在这一带沿着围绕L2的轨道运行，同时跟着地球一起绕太阳走。
Webb follows an orbit around L2 in this region while traveling around the Sun along with Earth.
这并不意味着引力完全消失，也不意味着它可以永远不用调整位置。
This does not mean gravity has disappeared or that the telescope can stay there forever without adjustments.
它仍需要定期使用发动机，修正偏离目标轨道的趋势。
It still needs periodic engine firings to correct its tendency to drift from the intended orbit.
那么，为什么选择这么远的地方？答案与它要接收的红外光有关。
Why choose such a distant location? The answer relates to the infrared light it observes.
温暖的物体会发出红外辐射，望远镜自己太热，就会干扰来自远处的微弱信号。
Warm objects emit infrared radiation; if the telescope is too warm, its own radiation can interfere with faint distant signals.
在L2附近的这种安排，让它可以用同一面遮阳板挡住太阳、地球和月亮方向来的光与热。
This arrangement near L2 allows one sunshield to block light and heat from the directions of the Sun, Earth, and Moon.
观测的一侧保持寒冷，太阳能板则仍然可以获得阳光来供电。
The observing side stays cold, while the solar array can still receive sunlight for power.
这也是为什么它不直接躲在地球的影子里，而是绕着L2运行，避开地球和月亮的阴影。
That is also why it does not simply hide in Earth’s shadow; it orbits L2 while avoiding the shadows of Earth and the Moon.
所谓合适的位置，原来是一种持续运动的安排：既挡热，又取光，还要不断保持轨道。
The right “location” is an arrangement in continuous motion: blocking heat, receiving sunlight, and maintaining an orbit.
