An unusual volcanic comet flying toward the sun appears to have "grown horns" after it exploded, causing it to shine like a small star and shower supercold "magma" into space. It is the first time this comet has been seen erupting in almost 70 years.
The comet, named 12P/Pons-Brooks (12P), is a cryovolcanic — or cold volcano — comet. Like all other comets, the icy object is made up of a solid nucleus, filled with a mix of ice, dust and gas, and is surrounded by a fuzzy cloud of gas called a coma, which leaks out of the comet's interior. But unlike most other comets, the gas and ice inside 12P's nucleus build up so much that the celestial object can violently explode, shooting out its frosty guts, known as cryomagma, through large cracks in the nucleus's shell.
