When Will We See Halley's Comet Next? A Look into Its Past and Future

Introduction

An occurrence so rare and mesmerizing that every one of us might experience it only once in our lifetimes. The star of one such show is Halley's Comet - a dazzling traveler of the cosmos that visits us roughly every 76 years as it orbits the Sun.

Named after the English astronomer Edmond Halley, who accurately predicted its return in the 18th century based on earlier sightings, the comet is composed of dust, ice, and other debris. It last appeared in 1986 and should return in 2061.

As we anticipate its next arrival, let's learn what a comet is, how it travels through our solar system, what impact it has left on our society, and how you can prepare for Halley's next visit.

The Science Behind the Spectacle

What is a Comet?

Before diving deeper into the Halley's Comets saga, let's address a fundamental question: what exactly is a comet? Simply put, a comet is a frozen ball of gas, dust, and rock that orbits around the Sun. Astronomers often call them "dirty snowballs" because of their composition.

Scientists believe they are the remains of the early solar system, which existed over 4.6 billion years ago. That is part of what makes them so fascinating.

You can usually find comets far out in the solar system, and they fall into two categories. Some travel around the sun in a few hundred years, like Halley's Comet, while others take much longer.

The first ones, also called the "short-period comets," take less than 200 years to go a full circle around the Sun. Meanwhile the long-period comets can take hundreds of thousands of years. The comet with the longest known orbit takes over 250,000 years to make one trip around the Sun.

The Journey of Halley's Comet

The story of Halley's Comet is, at its heart, a tale of a journey. This comet swings around the Sun in an elliptical orbit, at an extremely high speed. It spends most of its life in the distant, freezing reaches of the solar system. But every 76 years or so, its orbit brings it close to the Sun.

The Phenomenon of the Comet Tail

Comets are like cosmic ice cubes floating through space. When approaching the Sun, they melt and release gases and dust from their core, creating a glowing envelope known as a coma. The melted materials then create a pair of tails - a dust tail and a gas or ion tail of a comet. These streams of dust and gas each point in slightly different directions.

The dust tail always points away from the sun, no matter its direction. Meanwhile, the ion tail, made of gases, always points along the solar wind's streamline.

A Historical Glance at Halley's Comet

Ancient History

The fascinating tale of Halley's Comet goes back thousands of years. Believe it or not, our ancient ancestors were the first to spot this icy voyager. They might not have known exactly what it was, but they certainly recognized it was something special. People possibly recorded Halley as early as 467 BC, but that is uncertain.

Ancient Greeks documented a comet, likely Halley's, from 468 to 466 BC. Reports also mention a meteorite in Thrace during the same period.

But the first certain appearance of Halley dates back to 240 B.C. The Chinese chronicles mention a comet that appeared in the east and moved to the north.

Two incomplete Babylonian tablets, now in the British Museum, preserve the only documentation of the 164 BC appearance.

Comets in Ancient Beliefs

In many ancient societies, the arrival of a comet was an omen, signaling changes in power or even doom. Halley's Comet's spectacular show, in particular, made it a regular character in the annals of human history. In 1066, the English saw one and thought it was a bad omen. Later that same year, Harold II of England died in battle, and William the Conqueror claimed the throne. 

When Halley's Comet reappeared in 1456, the Ottoman Empire launched an attack on Hungary. The Pope asked for special prayers to protect the city. In 1470, a scholar wrote that when it appeared, people predicted sickness, hunger, and disasters would follow. The Turks and a Sanskrit poet also saw the comet and believed it meant trouble for their leader.

Edmond Halley and His Discovery

Scientists have been studying Halley's appearances since the 16th century. Our comet, however, gets its name from a man who lived much later, in the 17th and 18th centuries: Edmond Halley.

A contemporary of Isaac Newton and gifted English astronomer E. Halley noticed that the descriptions of comets seen in 1531, 1607, and 1682 were very much alike. He hypothesized that it wasn't three different comets but one, returning again and again. Halley wrote to Newton, asking for details about the one seen in 1682. He believed they had seen it three times since 1531 and wanted Newton to get data from Flamsteed.

One challenge was explaining why the comet's orbit changed, taking more time to return between 1531 and 1607 than between 1607 and 1682. Newton theorized that other comets might have caused these delays, but Halley discovered that Jupiter and Saturn were responsible.

Halley thought it moved in an orbit around the sun and predicted it would return in 1758. He didn't live to see it, but when it returned, just as he said, people named it in his honor.

Notable Appearances in Recent History

Fast-forwarding to more recent history, Halley's 1910 passage was a cause for both wonder and dread. Earth passed through its tail, and although it was harmless, the media sparked "comet fever" with claims the event would have catastrophic effects.

A snippet of a newspaper about the 1910 "comet fever".

During spectroscopic analysis, one of the substances detected in the tail was the poisonous gas cyanogen. Some newspapers wrongly said astronomers warned that this poison would fill the atmosphere and harm life on Earth. Despite scientists' assurances that the gas was not dangerous, the false information led to public alarm. This resulted in panic buying of gas masks and the sale of quack "anti-comet pills" and "anti-comet umbrellas."

Its 1986 visit was even more exciting. For the first time, spacecraft could meet the comet in its cosmic domain. The European Space Agency's Giotto spacecraft succeeded in capturing close-up images of its nucleus.

Halley's Comet and Popular Culture

Literature and Art

Long before the invention of telescopes, Halley graced our skies and sparked the imagination of artists and writers. It has appeared in famous art like the Bayeux Tapestry, which tells the story of the Norman Conquest of England in the 11th century.

A snippet of Bayeux Tapestry with the Halley's Comet embroidered on it.

The early 14th-century Florentine artist Giotto clearly portrays the Bethlehem Star as a comet in his artwork "Adoration of the Magi." Most people believe that Halley was the one who inspired Giotto because it flew by in 1301, just as he started his work.

Giotto's painting "Adoration of the Magi" with Halley's Comet in the background.

Mark Twain, born and died in years when Halley passed by, once famously said, "I came in with Halley's Comet... It is coming again, and I expect to go out with it." Several works of literature also mention it: Robert S. Richardson's 1946 short story "The Blindness," Fred Hoyle's 1985 novel "Comet Halley," and Diana Wynne Jones' 2007 novel "The Game."

In modern times, Halley's Comet has not lost its charm. It has appeared in movies, like the animated film Gulliver's Travels, where Gulliver calms down the panic caused by the comet's passing. It has also appeared in numerous TV shows, such as the popular science-fiction series Doctor Who.

Music hasn't overlooked Halley's Comet, either. Artists like Aimee Mann pay tribute to it in songs like "Patient Zero." Shinedown mentions it in their song "Second Chance," with lyrics like "I just saw Hayley's Comet." Billie Eilish even released a song in 2021 named after it, where she sings, "Halley's Comet comes around more than I do."

Waiting for the Next Appearance

When to Expect Halley's Return

Halley last visited us in 1986 and should next appear in mid-2061. Astronomers are already preparing to observe and study this cosmic celebrity as it swings by.

How to Prepare for the Next Viewing

Now that you know when to expect our cosmic guest, how can you prepare for this celestial spectacle? When the time comes, it will be visible to the naked eye. However, for a better viewing experience, be away from city lights and have a pair of binoculars or a telescope on hand.

This next appearance will likely usher in another wave of scientific discovery, as new technology will allow us to study Halley's Comet with even greater detail. For the layperson, pack your warm socks and some snacks and prepare for a spectacle in the night sky that you'll remember for a lifetime.

Conclusion

1. Comets like Halley's are icy remains from the early solar system, made of gas, dust, and rock, and are over 4.6 billion years old. They come in two main categories based on their orbital periods.
2. Halley follows an elliptical orbit. It spends most of its time in the outer solar system and comes close to the Sun every 76 years. Solar heat melts its icy core during its approach, creating the iconic coma and tails that define its appearance.
3. The tails of comets form when materials in their center evaporate as they come closer to the Sun. These tails, consisting of dust and gas, always point away from the Sun due to the solar wind's influence.
4. Throughout history, people have both revered and feared Halley's Comet. Ancient civilizations saw their appearances as omens of significant events. Its study and observation have inspired artists, writers, and scientists.
5. Halley last appeared in 1986 and should return in 2061.

References

1. Halley, E. (1705). "A Synopsis of the Astronomy of Comets". In Armitage, Angus (Ed.) (1966). John Wiley & Sons.
2. Brandt, J.C., Chapman, R.D., & Yeomans, D.K. (1992). "Introduction to Comets". Cambridge University Press.
3. Delsemme, A.H. (1988). "Comets: Creators and Destroyers". Touchstone.
4. Yeomans, D.K. (1991). "Comets: A Chronological History of Observation, Science, Myth, and Folklore." John Wiley & Sons.
5. "The Bayeux Tapestry and Halley's Comet." (2016). Astronomy & Geophysics, Volume 57, Issue 1.
6. "The Composition of Halley's Comet". (1986). Nature, Volume 321.
7. Wikipedia - "Halley's Comet"
8. Wikipedia - "Edmond Halley"
9. Wikipedia - "List of Halley-type comets"