A volcanic “devil comet” that’s racing toward Earth erupted again on Halloween, causing it to regrow its distinctive “horns.” The most recent outburst, which was the second inside a month and the third since July, is a reminder that the comet is becoming more volcanically lively because it continues its journey toward the center of the solar system.
The comet, named 12P/Pons-Brooks (12P), is a cryovolcanic, or cold volcano, comet. Like other comets, 12P has a solid nucleus — a tough, icy shell stuffed with ice, gas and dirt — that’s surrounded by a fuzzy cloud, or coma manufactured from materials that leak out of the comet’s insides.
But unlike non-volcanic comets, radiation from the sun can superheat 12P’s interior, causing pressure to accumulate until it becomes so intense it cracks the nucleus’ shell from the within and sprays its icy guts into space. These eruptions cause the comet’s coma to expand and brighten because it reflects more sunlight toward Earth.
When the comet erupts, its coma forms iconic devil “horns.” These occur because 12P’s large nucleus, which spans around 10.5 miles (17 kilometers) across, has an unusual “notch” on its surface, which blocks the outflow of cryomagma into space and causes its expanded coma to grow with an irregular shape.
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On July 20, astronomers spotted 12P blow its top for the primary time in 69 years when its misshaped coma grew to greater than 7,000 times wider than its nucleus. Then, on Oct. 5, experts watched because the comet exploded again with even greater intensity.
And last week, on Oct. 31, amateur astronomer Eliot Herman spotted one other outburst as 12P became almost 100 times brighter than usual, Spaceweather.com reported.
“On Halloween, the devil burst forth again with a big outburst that continued into the subsequent day,” Herman told Spaceweather.com. Subsequent observations showed that its coma expanded significantly and regrew its horns, although they weren’t as distinct as they were in previous eruptions, he added.
Approaching Earth
12P has an elliptical orbit, which suggests it gets pulled near the sun before being slingshotted back into the outer solar system, where it slowly drifts before eventually falling back toward the inner solar system. This trajectory could be very just like the orbit of the green comet Nishimura, which pulled off the same slingshot maneuver across the sun in September.
It takes around 71 years for 12P to finish one full trip across the sun, most of which is spent hidden within the outer solar system. In consequence, astronomers can only clearly see the comet because it begins to make its closest approach to the sun, which is occurring now.
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12P will reach its closest point to the sun, or perihelion, on April 24, 2024, when it’ll reach a minimum distance of 72.5 million miles (116.7 million km), which is closer to the sun than Earth but further away than Venus, in keeping with TheSkyLive.com.
After slingshotting across the sun, the comet will reach its closest point to Earth on June 2 next yr when it’ll pass by at a distance of 144.1 million miles (231.9 million km) — or around 1.5 times further away from Earth than the sun — on its way back out into the shadows of the outer solar system. It is going to remain there until 2094, in keeping with TheSkyLive.com.
Comets appear brighter within the night sky as they catch up with to the sun because their comas reflect more sunlight. This implies there may be an honest likelihood it’ll be visible with the naked eye in late May or early June because it flies by Earth.
As 12P gets closer to the sun, it may recurrently showcase its devilish horns because it soaks up more solar radiation that boils its icy guts and makes eruptions more likely.