Astronomers have found a giant interstellar cloud surprisingly close to Earth.
Lurking about 300 light-years from our solar system, this immense cloud of gas and dust is the closest of its kind ever found to Earth, beating the previous record holder by roughly 90 light-years. Despite being some 5,500 times as massive as the sun, the cloud went unnoticed — until now.
That’s because the cloud does not contain much carbon monoxide, the molecule astronomers often use to probe these clouds, called molecular clouds. Astronomers found this cloud by scanning the sky for ultraviolet light coming from a molecular cloud’s main constituent, hydrogen molecules. The results, published April 28 in Nature Astronomy, reveal a crescent-shaped cloud that, if visible, would appear to viewers on Earth as the largest single structure in the night sky — roughly 40 full moons wide.
Read the full article here