Primordial Gas Clouds
In 2011, astronomers have found clouds of the primordial gas that formed in the first few minutes after the Big Bang. The composition of the gas matches theoretical predictions, providing direct evidence in support of the modern cosmological explanation for the origins of elements in the universe. The researchers discovered the two clouds of gas by analyzing the light from distant quasars, using the spectrometer on the Keck I telescope. They saw absorption of the gas, and that allowed them to measure the composition of the gas.
Cosmic Neutrino Background
The Universe's background particle radiation is called the cosmic neutrino. It is particle radiation composed of neutrinos. They are sometimes known as the relic neutrinos. The cosmic background radiation dates from when the universe was 379,000 years. Since low energy neutrinos interact very weakly with matter, they are very difficult to detect and cosmic neutrino background may never be observed directly. There is, however, indirect evidence for its existence.