12P/Pons-Brooks To Reach Its Closest Point to the Sun; Here’s How To See the Cryovolcanic Comet in Its Best and Brightest Appearance

A comet with a rare volcanic eruption is about to reach its closest approach to the Sun, giving its best and brightest appearance in the coming days.

Devil Comet at Its Perihelion

On April 21, 12P/Pons-Brooks will reach its closest point to the Sun, known as perihelion. At this moment, the space rock will be about 144 million miles (232 million kilometers) from our host star.

This position will make the comet significantly brighter and more accessible to observe in the western sky just after sunset. At a magnitude of about 5.9, however, this celestial body may not be visible to the naked eye. The lower the magnitude, the brighter an astronomical object becomes. For comparison, Sirius, the brightest star in the night sky, shines at -1.46.

The best time to watch the comet at its brightest is April 21 and a few nights before and after. A good camera, telescope, or decent pair of stargazing binoculars will be essential. Meanwhile, skywatchers in northern latitudes may struggle to observe the comet since it will be positioned in the glow of sunset.

Comets are usually at their brightest and most accessible to view upon reaching their closest point to Earth. This happens in June, but by then, the comet's trajectory will make it visible only from the Southern Hemisphere. In any case, true darkness is complex to come by in the Northern Hemisphere by early June.

Although 12P/Pons-Brooks will approach its brightest appearance because it is nearest to the Sun, it is still quite distant from our planet, according to astronomy and astrophysics associate professor Frank Maloney from Villanova University in Pennsylvania. Maloney explains that comets can demonstrate significant changes in brightness as they get heated by the Sun. Unless something happens, they will be visible only in a telescope or binoculars.

Horned Comet

The space rock 12P/Pons-Brooks is a comet that orbits around the Sun every 71.3 years. As a Halley-type periodic comet, it is estimated to be 21.13 miles (34 kilometers) long, equivalent to the size of a city.

Jean-Louis Pons discovered this comet on July 12, 1812, and then independently rediscovered it in 1883 by William Robert Brooks. Comet 12P/Pons-Brooks is currently found in the Draco constellation and is considered the parent body that causes the K-Draconid meteor shower.

Since its discovery in the 19th century, the comet has been well-known in the scientific community. However, the space rock was initially not perceived as having huge horn-like emissions of light, which are about 7,000 times wider than the comet itself.

On July 20, 2023, experts from Elek Tamás of Harsona Observatory in Nyiregyhaza, Hungary, discovered a significant outburst from the comet. They saw that 12P/Pons-Brooks was 100 times brighter than the previous day. Currently, the celestial body has developed two horn-like patterns resembling the Millennium Falcon spaceship from Star Wars.

Comet 12P/Pons-Brooks is categorized as a cryovolcanic comet, which means that it contains a high amount of gas and ice build-up and can explode violently. The explosion emits frosty guts called cryomagma, which are released from the large cracks developed in the shell of the nucleus. Unlike the volcanoes on Earth, the magma spewed by cryovolcanic comets is not an actual magma of molten rocks but a mixture of gases and liquid hydrocarbons.