Scientists discover massive hidden molecular cloud near Earth

Express Tribune

29-04-2025

The molecular cloud was detected 300 light-years from Earth, closer than any other similar, star-forming clouds. PHOTO:Thomas Müller (HdA/MPIA)/Thavisha Dharmawardena (NYU)
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A massive, previously undetected molecular cloud has been discovered surprisingly close to Earth, offering new insights into how stars and planets form.
Named "Eos" after the Greek goddess of dawn, the cloud spans an area roughly 40 times the width of the full moon and carries a mass about 3,400 times greater than the sun, according to a study published Monday in Nature Astronomy.
Located just 300 light-years away, Eos is now recognized as the nearest known molecular cloud to our solar system.
Its discovery was a surprise to astronomers, who believed they had mapped all nearby molecular clouds.
Eos had remained hidden because it contains very little carbon monoxide, the chemical signature typically used to detect such clouds.
Researchers instead spotted Eos by analyzing far-ultraviolet emissions from hydrogen molecules — a method not previously used to find molecular clouds.
The data was gathered by FIMS-SPEAR, a spectrograph onboard the Korean STSAT-1 satellite, and recently made publicly available.
"This cloud is literally glowing in the dark," said lead study author Blakesley Burkhart, an astrophysicist at Rutgers University.
Scientists believe Eos's proximity presents a rare opportunity to directly observe the processes of molecular cloud formation and star birth.
Eos sits along the edge of the Local Bubble, a gas-filled cavity surrounding our solar system.
Researchers estimate the cloud will eventually evaporate within the next 6 million years.
Despite its enormous size and mass, Eos poses no threat to Earth.
Astronomers hope this discovery will open a new chapter in the study of the interstellar medium and the life cycle of stars, using far-ultraviolet techniques to uncover other hidden structures in space.