astronomers use a wide variety of technology to explore space and the electromagnetic spectrum; why do you believe it is essential to use many types of equipment when studying space?

It is essential to use a number of telescopes sensitive to different parts of the electromagnetic spectrum to study objects in space. Even though all light is fundamentally the same thing, the way that astronomers observe light depends on the portion of the spectrum they wish to study. Tools are useful, such as detectors that help see the different wavelengths of light. Not all light can get through the Earth's atmosphere, so for some wavelengths we have to use telescopes aboard satellites.

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The universe comprises billions of stars, planets, galaxies, comets, asteroids, and various other distinct kinds of heavenly bodies. These objects discharge radiations of different frequencies. So, in order to examine these distinct types of objects, distinct types of technologies are needed.  

There are different kinds of missions, that is, some orbit the bodies, while some comprise probes that lands on the surface. While some are the space observatories that comprises detectors to examine light from far off objects. Also, there are various detectors for various wavelengths of the electromagnetic spectrum.  

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the answer for sodium is 0.186

the answer for rubidium is 0.251