5 Famous Comets that Fascinated Earthlings

English astronomer Edmond Halley didn’t discover the famous comet that bears his name, but Halley was the first person to accurately predict a comet’s return. In 1705, Halley made a bold hypothesis—that three bright comets reported in 1531, 1607 and 1682 were actually the same comet on a roughly 76-year orbit of the sun. On Christmas night in 1758, the comet made its dazzling return, proving Halley’s theory to be true.

Halley’s comet was first spotted by ancient sky watchers as far back as 240 B.C. The comet made its most recent pass in 1986 and when it returns in 2061, Halley's comet is predicted to be 12 times as bright.

In astronomy, comets are usually named after their discoverers. This doomed space traveler was first spotted in 1993 by Carolyn and Eugene Shoemaker—a professional astronomer and geologist, respectively—and amateur astronomer David Levy. It was the ninth comet the trio discovered and by far the most famous.

When it was found, the Shoemaker-Levy comet had been captured by Jupiter’s gravity and was on a collision course with the gas giant. Over the next year, it broke apart into 20 fragments, then slammed into Jupiter with a force equal to 300 million atomic bombs.

Each impact produced a massive fireball visible from Earth and left dark scars in Jupiter’s atmosphere, the largest measuring 1,550 miles across.

It takes more than 2,500 years for the Hale-Bopp comet to orbit the sun, part of why its appearance in 1997 was so spectacular. Measuring 37 miles in diameter, Hale-Bopp is a very large comet—five times the size of the space rock that killed off the dinosaurs. Because of its size and its positioning, Hale-Bopp was visible to the naked eye for an unprecedented 18 months, doubling the record set by the Great Comet of 1811.

Sadly, the magnificence of Hale-Bopp's appearance in 1997 was overshadowed by the mass suicide of 39 members of the Heaven’s Gate cult in California. The victims believed that a spaceship hidden behind the comet was going to transport them to another plane of existence. The Hale-Bopp comet isn’t expected to return until 4385 or later.

Discovered in 1996 by Japanese amateur astronomer Yuji Hyakutake using long-range binoculars, the Hyakutake comet became famous for its exceptionally long and colorful tail.

When a comet nears the sun, it heats up and begins releasing frozen gases and dust. The hotter it gets, the larger its head, or “coma,” appears—sometimes brighter in the sky than most planets. Meanwhile, the solar wind blows a stream of gas and dust away from the sun, forming the comet's long tail.

Hyakutake’s tail stretched more than 300 million miles, the longest comet tail ever observed. On March 25, 1996—the comet’s closest approach to Earth—it dazzled sky watchers with streamers of blue, purple and green visible to the naked eye.

In Hawaiian, ‘Oumuamua means “a messenger from afar arriving first.” This small, disc-shaped object made headlines in 2017 as the first known visitor from outside our solar system. Its official name, 1I/‘Oumuamua, indicates it was the first “interstellar” traveler ever discovered.

Astronomers don’t know where ‘Oumuamua came from, but it zipped through the sky at 196,000 miles per hour. It was moving too fast to be captured by the sun’s gravity, though the object's path was bent by the sun's powerful pull.

At first it wasn’t clear whether ‘Oumuamua was a comet or an asteroid. Asteroids are small rocky bodies, while comets are covered in ice. ‘Oumuamua was tiny—about 377 feet long, 364 feet wide and 62 feet thick. Seen through powerful telescopes, it lacked a visible coma or tail, suggesting it was a rocky asteroid rather than an icy comet.

But astronomers also noticed that ‘Oumuamua accelerated as it passed the sun. One explanation is that it was off-gassing hydrogen from an icy surface, propelling it through space. If so, ‘Oumuamua was indeed a comet.

A second interstellar visitor, 2I/Borisov, arrived in 2019 and looked much more like a classic comet. In July 2025, astronomers spotted a third interstellar object, a comet named 3I/ATLAS, which may have come from a region of the universe about 3 billion years older than our solar system.