Astronomers have made a groundbreaking discovery, unveiling the closest known molecular cloud to Earth, named Eos. Located 300 light-years from our planet, this enormous cloud is one of the largest structures in the night sky, spanning about 100 light-years wide. Despite its massive size, it had eluded detection due to its low content of carbon monoxide, a bright chemical signature used to identify molecular clouds.
The discovery was made possible by a novel approach that detected the cloud’s hydrogen molecules through their fluorescent glow. Researchers led by Blakesley Burkhart found Eos while analyzing 20-year-old data from a spectrograph aboard the Korean Science and Technology Satellite-1. The team reported their findings in a paper published April 28 in the journal Nature Astronomy.
Eos is an enormous, crescent-shaped blob of hydrogen gas that has been sculpted into its unique shape by interactions with nearby cosmic features. Its discovery hints at the presence of many previously unseen clouds throughout the galaxy. While it will evaporate in about 6 million years due to incoming photons and high-energy cosmic rays, further research is needed to determine whether it will form stars before dissipating.
The researchers’ novel approach could reveal many similarly hidden clouds, allowing astronomers to uncover previously undetected hydrogen reservoirs and more precisely gauge the amount of material available for star and planet formation. A proposed Eos space telescope would observe in far-ultraviolet wavelengths to measure the molecular hydrogen content in clouds across the Milky Way, enabling a census of its formation and destruction.
Burkhart notes that “there’s still tons of open questions,” but this discovery is a significant step forward in understanding the galaxy. As researchers continue to explore and study Eos, they are answering one of the century’s most pressing questions: where did the oldest gold in the universe come from?
Source: https://www.livescience.com/space/astronomy/its-huge-and-its-been-hidden-for-this-whole-time-gigantic-glow-in-the-dark-cloud-near-earth-surprises-astronomers