A comet with horns? Believe it. On July 20th, something on the surface of Comet 12P/Pons-Brooks exploded, increasing its brightness 100-fold. Debris from the outburst looks like this:
Comet 12P/Pons-Brooks
"Here is a quick view of Comet 12P/Pons-Brooks taken last night between some high clouds," reports Thomas Wildoner of Weatherly, PA. "Just in the last several days, this comet has gone from a star-like appearance to brightening by five magnitudes and now sporting a coma in the shape of two horns."

Comet 12P/Pons-Brooks is famous for exploding. Discovered in 1812 by Pons and discovered again in 1883 by Brooks, the bursty comet visits the inner solar system every 71 years. Since the 19th century at least 7 significant outbursts have been observed, suggesting that it might be a cryovolcanic comet like 29P/Schwassmann-Wachmann.

Comet 12P/Pons-Brooks
The comet is currently beyond the orbit of Mars, but falling toward the sun for a close encounter in April 2024. At that time it is expected to become a naked-eye object at 4th or 5th magnitude. Given its history of outbursts, however, the moment of easy visibility could come sooner.

Amateur astronomers are encouraged to monitor developments. Comet 12P is currently crossing the head of Draco not far from the north celestial pole. With an astronomical magnitude of +11, it is an easy target for mid-sized backyard telescopes. Check out those horns! And submit your photos here.