Disintegrated.....

Halloween comet’s final moments captured by SOHO spacecraft

By Taylor Nicioli

 A comet nicknamed the “Halloween comet” disintegrated on Monday during its closest approach of the sun, and the European Space Agency and NASA’s Solar and Heliospheric Observatory mission captured footage of its final moments.

Astronomers first discovered Comet C/2024 S1 (ATLAS) on September 27 via an Asteroid Terrestrial-impact Last Alert System in Hawaii, and the glowing celestial body quickly earned its nickname following speculation that it might be visible in the night sky near the end of the month. But as the comet, composed of ice, frozen gases and rock, came closer to its perihelion — the nearest point to the sun in its orbit — over the past few days, it broke apart into chunks until it finally evaporated, according to NASA.

C/2024 S1 was a sungrazer, a comet that passes within a distance of about 850,000 miles (1,367,942 kilometers) from the sun. Sungrazers often vaporize due to the intense, hot solar atmosphere.

“Comets are really hard to predict, and sungrazing comets like this are even harder than most. At discovery time, astronomers were somewhat divided on whether it would survive or not, which just speaks to that uncertainty,” said Karl Battams, a computational scientist based at the Naval Research Laboratory in Washington, DC. Battams is also principal investigator for the Large Angle and Spectrometric Coronagraph instrument suite, a set of three telescopes on the Solar and Heliospheric Observatory, or SOHO, spacecraft that image the sun’s atmosphere.

The comet reached its perihelion on Monday at 7:30 a.m. ET and was completely vaporized after passing within 1% of Earth’s distance from the sun, less than 1 million miles (1.5 million kilometers) away from the star, according to NASA. In comparison, comet C/2023 A3 Tsuchinshan–ATLAS, a comet from the Oort Cloud that survived its perihelion on September 27, did not get closer to the sun than a third of Earth’s distance from the star. (Our planet is about 93 million miles, or 149 million kilometers, away from the sun.)

“Statistically, it’s extremely rare for sungrazing comets to survive (as they fly) past the Sun,” Battams told CNN in an email. NASA’s Sungrazer Project, a citizen science project that discovers previously unknown comets, which Battam is the lead for, has discovered more than 4,000 sungrazing comets and none have survived their perihelion, he added.

A handful of larger sungrazing comets have been observed surviving their close pass by the sun, such as comet C/2011 W3 Lovejoy in 2011. Initially discovered using a ground telescope, C/2011 W3 Lovejoy was the brightest sungrazing comet that SOHO has imaged, but these larger comets are “few and far in between,” Battams said.

Other visible celestial bodies

“Between now and 2030, only three known comets are expected to reach naked eye visibility (C/2024 E1, C/2024 G3 and 22P/Kopff),” said William Cooke, lead of NASA’s Meteoroid Environment Office, in an email. There may also be a comet or two yet to be discovered that could get bright enough to see, he added.

The Halloween comet, C/2024 S1, was a member of the Kreutz family of comets, a population of mostly tiny comet fragments originating from a single parent object that fell apart near the sun presumably thousands of years ago, Battams said. Astronomers captured images of the Halloween comet as it was visible earlier in the month, but never observed it with the naked eye, he added.

C/2023 Tsuchinshan–ATLAS was visible in the night sky without equipment in mid-October but is now fainter and is most likely only visible with a telescope or binoculars, Cooke said. Astronomers originally estimated that the comet would circle back in about 80,000 years, but as of October 14, observational data revealed the comet had a new path that could remove it from our solar system completely.

If the conditions are right, comets can leave debris trails that cause meteor showers if Earth’s orbit encounters their path, such as the October Orionids which are particles from the famous Halley’s comet. The next meteor shower, the Southern Taurids, is expected to peak on the night of November 4 into the early morning of November 5 and also has a comet for a parent body called Comet Encke.

However, any debris from C/2023 Tsuchinshan–ATLAS or C/2024 S1 will not pass near enough to Earth to produce a meteor shower, Cooke said.

How often comets are visible in our skies is variable, with some years offering up a handful of the icy bodies that sky-gazers can spot and others not so fruitful, Battams said.

“Historically, comets have always been a source of fascination to people, in part due to the fact that they are such infrequent occurrences,” he added. “I’m sure back in pre-industrial times when light pollution was no concern, some of the comets that people saw must have been equally awe-inspiring and terrifying!”