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Explanation: How does a comet tail change? It depends on the comet. The ion tail of Comet 12P/Pons–Brooks has been changing markedly, as detailed in the featured image sequenced over nine days from March 6 to 14 (top to bottom). On some days, the comet's ion tail was relatively long and complex, but not every day. Reasons for tail changes include the rate of ejection of material from the comet's nucleus, the strength and complexity of the passing solar wind, and the rotation rate of the comet. Over the course of a week, apparent changes even include a change of...

Explanation: In dark evening skies over June Lake, northern hemisphere, planet Earth, Comet 12P/Pons-Brooks stood just above the western horizon on March 30. Its twisted turbulent ion tail and diffuse greenish coma are captured in this two degree wide telescopic field of view along with bright yellowish star Hamal also known as Alpha Arietis. Now Pons-Brooks has moved out of the northern night though, approaching perihelion on April 21. On April 8 you might still spot the comet in daytime skies. But to do it, you will have to stand in the path of totality and look away from the...

Explanation: Comet Pons-Brooks has quite a tail to tell. First discovered in 1385, this erupting dirty snowball loops back into our inner Solar System every 71 years and, this time, is starting to put on a show for deep camera exposures. In the featured picture, the light blue stream is the ion tail which consists of charged molecules pushed away from the comet's nucleus by the solar wind. The ion tail, shaped by the Sun's wind and the comet's core's rotation, always points away from the Sun. Comet 12P/Pons–Brooks is now visible with binoculars in the early evening sky toward...

Explanation: Heading for its next perihelion passage on April 21, Comet 12P/Pons-Brooks is growing brighter. The greenish coma of this periodic Halley-type comet has become relatively easy to observe in small telescopes. But the bluish ion tail now streaming from the active comet's coma and buffeted by the solar wind, is faint and difficult to follow. Still, in this image stacked exposures made on the night of February 11 reveal the fainter tail's detailed structures. The frame spans over two degrees across a background of faint stars and background galaxies toward the northern constellation Lacerta. Of course Comet 12P's April...

Scientists are reporting that a “horned” comet three times bigger than Mount Everest is hurtling toward Earth after encountering a large explosion. The blast originated on October 5 from 12P/Pons-Brooks a cryovolcanic — or cold volcano — comet. According to Live Science, the comet, nicknamed the “Devil” due to its apparent horns, measures a colossal 18.6 miles in diameter, or the size of a small city. For reference, Mount Everest, the highest mountain on Earth, is about 5.5 miles high. This marked the second time this interstellar ice cube erupted in the last four months. The Science Times reports that...

A composite image showing Comet 12P/Pons-Brook (left) and a model of the Millennium Falcon spaceship from "Star Wars" (right). (Comet Chasers/Faulkes Telescope Project/Las Cumbres Observatory/Reuters/Insider) Astronomers have spotted a "once-in-a-lifetime" comet shaped like the Millennium Falcon – and sky gazers may soon be able to see it for themselves without a telescope. The comet, known as Comet 12P/Pons-Brooks, abruptly brightened 100-fold on July 20 as plumes of debris and ice were blasted off it into space. This gave it a horseshoe shape, which scientists likened to the Millennium Falcon spaceship from "Star Wars." The comet will make its closest approach...