Scientists Successfully Detect Light of 'Cosmic Dawn' on Earth for the First Time
Reborn from the Dark Ages: Earthbound Telescopes Unveil the Dawn of Stars
For the very first time, scientists have successfully peered back into the cosmic dawn, an epoch over 13 billion years old when the first stars began sculpting our universe. This groundbreaking feat was achieved by the Cosmology Large Angular Scale Surveyor (CLASS) project, who, using a specially crafted telescope, managed to detect remnants left by the universe's first stars on the background light of the Big Bang.
The residual light from this ancient era is millimeters in width and uncomfortably faint. Although space-based observatories have peered into it, the signal is often drowned out by Earth's atmosphere before ground-based telescopes can detect the primordial light. But with a strategic location and a telescope designed for the task, the CLASS team has triumphantly broken through these barriers.
The CLASS observatory is nestled in the Andes mountains of northern Chile's Atacama desert, at an altitude of 16,860 feet (5,138 meters). The telescope, which first captured the light of the stars in 2016, is finely-tuned to survey the sky at microwave frequencies. This delicate instrument not only allows it to map 75% of the night sky but also boasts an unprecedented sensitivity, permitting it to receive and analyze microwave signals from the cosmic dawn, or the universe's first billion years.
For the first 380,000 years after the Big Bang, the universe was shrouded by an electron cloud that was so dense that light couldn't penetrate it. As the cosmos expanded and cooled, these electrons were captured by protons, forming hydrogen atoms. These hydrogen atoms enabled microwave-wavelength light to move freely, filling the universe with the cosmic microwave background (CMB). In areas where the hydrogen was dense enough, it collapsed under gravity and ignited to form the first stars. The light from these stars then reionized pockets of unclumped hydrogen gas, causing some electrons to collide with light from the CMB and polarize it.
The polarized portion of the CMB forms a crucial part of the cosmic puzzle. Without it, our understanding of the early universe remains hazy. Although past space-based telescopes, such as NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency's Planck space telescope, have filled in some of the gaps, they are unable to tweak and improve their readings once deployed in orbit.
To make these groundbreaking observations, the researchers compared CLASS telescope data with data from the Planck and WMAP missions, carefully isolating a common signal for the polarized microwave light. This endeavor will lead to more precise measurements of the reionization signal and help refine our comprehension of the early universe, shedding light on dark matter and neutrinos, elusive particles that fill the cosmos.
"Astronomy is a field held back by technology," study co-author Tobias Marriage, CLASS project leader and a professor of physics and astronomy at Johns Hopkins University, stated in a release. "Ground-based observations face additional challenges compared to space. Overcoming those obstacles makes this measurement a significant achievement."
So here we are, reaping the rewards of years of tireless research and technological advancement that have culminated in this revolutionary discovery. The dawn of the stars has been unveiled, providing astronomers with a newfound understanding of our universe's early days. As beneficial as this newfound knowledge is, the awe-inspiring journey that lies ahead is equally compelling, inviting us to dig deeper into the mysteries of the cosmos.
- The Cosmology Large Angular Scale Surveyor (CLASS) project, utilizing science, technology, and a specially crafted telescope, successfully detected remnants of the universe's first stars on the background light of the Big Bang, opening a new chapter in space-and-astronomy.
- With a strategic location and a telescope designed for the task, ground-based observations such as the CLASS observatory, despite facing challenges from Earth's atmosphere, have made significant breakthroughs, such as helping refine our comprehension of the early universe by shedding light on dark matter and neutrinos.
