Scientists have successfully used Earth-based telescopes to study the universe’s earliest moments, known as the Cosmic Dawn. By analyzing polarized microwave light from 13 billion years ago, researchers have gained new insights into the formation of the first stars and the Big Bang.
Using high-altitude telescopes in northern Chile’s Andes mountains, a team led by Johns Hopkins University measured the faint signal of cosmic microwaves, which were previously thought to be too difficult to detect from Earth. The achievement is significant, as it confirms that ground-based observations can rival those made in space.
The researchers compared data from the CLASS telescope with that from previous space missions, such as the Planck and WMAP satellites. By identifying common signals, they refined their understanding of the cosmic microwave background and its polarization patterns.
This breakthrough has important implications for cosmology research, allowing scientists to refine their knowledge of dark matter and neutrinos. Further analysis of CLASS data will help push the limits of precision in measuring the universe’s earliest moments.
The project is supported by the National Science Foundation (NSF) and built upon previous research that mapped 75% of the night sky using CLASS telescopes. The NSF’s long-term support has enabled the team to make this significant leap forward, demonstrating the value of ground-based astronomy in understanding the universe.
Source: https://phys.org/news/2025-06-earth-based-telescopes-fresh-cosmic.html