If you want to check on what conditions were like in the universe a few hundred thousand years after the Big Bang, what sort of instrument would it be best to use:

Question

Quizplus · Accepted Answer

The best choice would be a satellite with infrared and microwave telescopes on board as these wavelengths of light are ideal for studying the cosmic microwave background radiation, which is the afterglow of the Big Bang that can provide information on the conditions in the early universe. Gamma-ray or high-energy x-ray telescopes would not be useful for this purpose, and a small visible light refractor or an ultra-violet telescope would not be sensitive enough to detect the faint signals from the cosmic microwave background radiation. A tank of chlorine deep inside the Earth would also not be relevant for studying the early universe.

If You Want to Check on What Conditions Were Like