February 23, 2024
3 1 minute read
A stunning comet could set off a total solar eclipse next April
Comet 12P/Pons-Brooks will reach its closest approach to the Sun next April, just after North America experiences a total solar eclipse.
12P/Pons–Brooks is a periodic Halley-type comet with an orbital period of 71 years. It was discovered in 1812 and was later recovered during passes in 1883 and 1954. It is expected to brighten to an apparent magnitude of 4.5 (visible to the naked eye) during its next pass in April 2024.
This article is part of a Special report In a total solar eclipse that will be visible from parts of the United States, Mexico, and Canada on April 8, 2024.
On April 8, a wide area of Mexico, the United States and Canada will see a total solar eclipse, the second such eclipse widely visible in the United States in less than a decade. But this time the comet might spoil the screen.
The dirty ball of ice, officially known as Comet 12P/Pons-Brooks, was discovered in 1812. It takes the comet just over 71 years to orbit the sun on a path that sends it past the orbit of Neptune and then diving back through the planet. Inner solar system. During Comet 12P’s current pass, professional and amateur astronomers have observed a series of outbursts from the hurtling ball of ice that appear to give it horns, earning it nicknames such as the “Millennium Falcon” and “Devil Comet.”
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“This is one of the brightest comets in history,” says Rosita Kokotanikova, a planetary scientist at the Institute of Astronomy and National Astronomical Observatory of the Bulgarian Academy of Sciences.
Comet 12P will reach its closest approach to the Sun on April 21, less than two weeks after the total solar eclipse. The timing means that the comet will appear about 25 degrees from the sun during the total eclipse. (You can use your clenched fist at arm’s length to measure about 10 degrees in the sky.)
Credit: Katie Beck. Source: NASA (Eclipse path data)
The visibility of Comet 12P during its totality remains uncertain. Although the Sun will be eclipsed at that time, the sky will not reach true nighttime hues — it will be more like twilight — and our star’s outer atmosphere, or corona, will be bright as well. Based on current observations, during the entirety of the comet, the comet may be barely visible to the naked eye, or sky watchers may need binoculars to spot it.
“I don’t want people to be disappointed if they don’t see the comet,” Kokotanikova says. “If people expect to see something very bright in a completely dark sky, I think unless we get lucky with an explosion, it will be more difficult than that.”
But if the comet cooperates, it may appear brighter. That’s because comet 12P is known for its dramatic explosions, during which the ice ball loses a large amount of material, whether ice that sublimates into gas or dust that spills into the surrounding space. This causes the comet to appear brighter by increasing the size of the mysterious halo surrounding it.
“It had some amazing explosions,” Kokotanikova says of comet 12P. She adds that scientists are not yet sure of the causes of this phenomenon, as some researchers have assumed that cracks are opening in the comet’s icy body, or that the slopes on its potentially jagged surface are collapsing. “It’s very uncharted territory,” she says. “That’s why we’re interested in every comet that does this.”
Whatever the cause of 12P’s outbursts, their well-timed occurrence can transform Comet 12P’s overall appearance from subtle to stunning. However, our limited records of the comet’s previous approaches to the Sun suggest that its outbursts may have subsided as it approached our star, another mystery that scientists will have to address in the coming months.
Although total solar eclipses and bright comets are relatively rare phenomena, comet 12P will not be the first to appear during a total eclipse. One historian reported the discovery of a different comet during a total solar eclipse over what is now Turkey in 418 AD, for example. Since the late 19th century, observers have often spotted “sun-grazing” comets — which pass about 850,000 miles from the star — during eclipses. It is particularly noteworthy that in 1997, Comet Hale-Bopp made its closest approach to Earth just two weeks after a total solar eclipse. We’ll just need to wait a little longer to see how Comet 12P/Pons-Brooks compares.