在很长的一段时期内,光学望远镜是观测宇宙的无限空间的唯一工具。只有在不久以前,才发明了新的工具,这种工具是利用电磁波谱的其他部分—无线电波区域—来观测的。画在封面上的巨大建筑物,就是最新型的天文仪器——无线电望远镜。在它们里面,没有普通光学望远镜所特有的那些镜筒、凹面镜和物镜。这种望远镜上的碗状栅跟巨大的雷达天线很相像。我们银河系(包括太阳在内)的许多恒星以及银河外的许多天体,都辐射出各种不同波长的电磁波。最强的波是从银河以及从可见的怛星最密集的空间区域发出来 For a long period of time, the optical telescope was the only tool for observing the infinite space of the universe. Only a short time ago, a new tool was invented that was observed using the other part of the electromagnetic spectrum, the radio wave area. The huge building painted on the cover is the latest type of astronomical instrument, the radio telescope. Inside them, there are no lens tubes, concave mirrors, and objective lenses that are unique to ordinary optical telescopes. The bowl grid on this telescope is very similar to the huge radar antenna. Many of our stars in the Milky Way (including the Sun) and many objects outside the Milky Way radiate electromagnetic waves of various wavelengths. The strongest waves are emitted from the Milky Way and from the most densely visible space of comets.