Earth Telescope Just Rewrote Cosmic History!

Unveiling the Dawn: Earth-Based Telescope Achieves Unprecedented Observation of the Early Universe

In a landmark achievement that was once deemed impossible, scientists have successfully used Earth-based telescopes to peer back into the "cosmic dawn" – a pivotal era over 13 billion years ago when the very first stars illuminated our universe. This groundbreaking observation, achieved by the Cosmology Large Angular Scale Surveyor (CLASS) project, opens a new window into understanding the universe's infancy.

Challenges and Triumphs in Cosmic Exploration

The residual light from this ancient epoch exists as faint, millimeter-wavelength signals. Traditionally, these signals have been obscured by electromagnetic radiation in Earth's atmosphere, rendering them undetectable by ground-based telescopes. While space-based observatories have offered glimpses into this era, they come with their own limitations.

However, the CLASS team, led by Tobias Marriage, a professor of physics and astronomy at Johns Hopkins University, defied expectations. They designed and deployed a specialized telescope that could effectively filter out atmospheric noise and detect the subtle traces left by the first stars on the background light of the Big Bang. Their findings were published on June 11 in The Astrophysical Journal.

Overcoming Obstacles: A Testament to Human Ingenuity

“People thought this couldn't be done from the ground," stated Tobias Marriage. "Astronomy is a technology-limited field, and microwave signals from the Cosmic Dawn are famously difficult to measure. Overcoming those obstacles makes this measurement a significant achievement."

Key elements of their success include:

• High-Altitude Location: The CLASS observatory is strategically located at an altitude of 16,860 feet (5,138 meters) in the Atacama desert of northern Chile, a region known for its exceptionally dry and clear atmosphere.
• Microwave Frequency Tuning: The telescope is specifically tuned to survey the sky at microwave frequencies, optimizing its ability to detect faint signals from the cosmic dawn.
• Unprecedented Sensitivity: The telescope's exceptional sensitivity allows it to map a remarkable 75% of the night sky and capture these elusive microwave signals.

Unraveling the Mysteries of Reionization

The first 380,000 years after the Big Bang saw the universe cloaked in a dense cloud of electrons, preventing light from traveling freely. As the cosmos expanded and cooled, these electrons combined with protons to form hydrogen atoms. This transformation allowed microwave-wavelength light to propagate, creating the cosmic microwave background (CMB).

Subsequently, pockets of dense hydrogen collapsed under gravity, igniting the first stars. The light from these stars then reionized clumps of hydrogen gas, causing some to collide with CMB light, resulting in polarization. Detecting this polarized portion of the CMB is crucial for completing our understanding of the early universe.

Complementing Space-Based Observations

Past space-based missions like NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency's Planck space telescope have contributed to our understanding, but they are limited by noise and the inability to be adjusted once in orbit. The CLASS project provides complementary data and a new avenue for refining our knowledge.

A Universe as a Physics Lab

By comparing CLASS data with that from Planck and WMAP, researchers were able to isolate a common signal for polarized microwave light. “For us, the universe is like a physics lab," explained Charles Bennett, a physics professor at Johns Hopkins who led the WMAP space mission. "Better measurements of the universe help to refine our understanding of dark matter and neutrinos, abundant but elusive particles that fill the universe."

Looking Ahead: A Future of Precision Cosmology

The CLASS project's achievement marks a significant leap forward in cosmology. By continuing to analyze CLASS data, scientists hope to achieve the highest possible precision in measuring the reionization signal and further refine our understanding of the universe's fundamental components.

This remarkable feat showcases the power of human ingenuity and the unwavering pursuit of knowledge, proving that even the most seemingly insurmountable challenges can be overcome with dedication and innovative technology. The cosmic dawn is now a little brighter, thanks to the CLASS project.

Tags: Cosmic Dawn, Early Universe, First Stars, Telescopes, Astronomy, Big Bang, Space, Cosmology, Astrophysics, Ground-Based, Microwave Background, Reionization

Source: https://www.livescience.com/space/astronomy/people-thought-this-couldnt-be-done-scientists-observe-light-of-cosmic-dawn-with-a-ground-based-telescope-for-the-first-time-ever