What is the significance of cosmic background radiation in the study of the universe?

Cosmic background radiation is significant in the study of the universe as it provides compelling evidence for the Big Bang theory. This radiation is a faint microwave signal that fills the universe, remaining from the early moments after the Big Bang, when the universe was still extremely hot and dense. As the universe expanded and cooled, this radiation was released, forming a uniform background that we can still detect today.

The discovery of this radiation in the 1960s supported the Big Bang theory by showing that the universe had a hot, dense origin and has since expanded and cooled. This detection of cosmic background radiation is a critical piece of evidence that aligns with predictions made by the Big Bang model, making it a cornerstone of our understanding of cosmic evolution and the origins of the universe.

In contrast, while other options mention different phenomena, they do not relate to the fundamental role of cosmic background radiation in cosmology. For instance, asteroid collisions and predictions of supernova explosions pertain to specific local astronomical events rather than the overall framework of cosmic history and evolution connected to the Big Bang. The age of Earth is established through different dating methods, such as radiometric dating, rather than cosmic background radiation, which pertains to the wider context of the universe's development.