There is no doubt that Halley’s Comet is the most famous comet.It is so well-know because of its orbital period. Being a periodic comet, it passes across the Earth every 75 years, which makes it possible for every person to witness it at least once in their lifetime.The comet appeared last in 1986 (when scientists got to see the first view of Halley’s surface), and the comet’s return will be again in 2061.Comets were termed as just mere disturbances in the Earth’s atmosphere. A huge group of comets has the name ‘Halley family comets’ as they have the same orbital path features as Halley. They are all also inclined a lot to the Earth’s orbit and also the other solar system’s planets. This family, on the other hand, has a wide variety of inclinations, prompting some astronomers to speculate that they could have various other origins than Halley’s. Sublimating ices such as carbon monoxide, water, and carbon dioxide ice generate an ‘atmosphere’ that could be as large as 62,137.12 mi (100,000 km) across as the comet reaches the Sun, which is astounding considering Halley’s nucleus is only around 9.32 mi (15 km) long, 4.97 mi (8 km) wide, and 4.97 mi (8 km) thick. The solar wind blows away much of this atmosphere, leaving a trail that can be 6.21 million mi (10 million km). The compounds around the comet-like silicates are similar to those found in terrestrial rocks.In 1986, Halley’s comet was captured by Europe’s Giotti spacecraft and the Vega 1 and Vega 2 spacecraft of Russia. Mark Twain, an American writer, was born on November 30, 1835, two weeks after Halley’s Comet appeared. He mentioned in his biography that he would die with Halley’s comet as he was born around that time. Mark Twain died on April 21, 1910, just one day after Halley’s comet appeared.Halley’s Comet is as dark as coal and reflects only 4% of the light it receives. It only shines brilliantly when it gets close enough to the Sun to burn off its dust and vapors. Once, scientists sent a spacecraft to look closely at Halley’s comet when it passed close to Earth.Facts about Comet HalleyNow let’s have a look at some facts about this marvelous comet.The orbit of Halley’s Comet around the Sun takes 75-76 years to complete. Comets orbit the Sun in elliptical orbits, ranging from a great distance away to close proximity (a few million miles). They begin to glow as they come closer to the Sun. As Halley’s Comet approaches the Sun every 75-76 years, it becomes visible in the sky at night, resembling a smudged star.Halley’s Comet is 35 astronomical units from the Sun at its furthest point (aphelion). One astronomical unit is the distance between the Earth and the Sun, which is approximately 93 million mi (150 million km). As a result, 35 astronomical units equal 35 times the distance between the Earth and the Sun. That’s almost as far from the Sun as Pluto is. Halley’s Comet is 0.57 astronomical units from the Sun at perihelion, making it nearer to the Sun as compared to Venus, the second nearest planet to the Sun.As Halley was able to forecast the comet’s reappearance, scientists and academics have been able to study historical astronomy records for previous comet observations. The Chinese chronicle Records of the Grand Historian contains the earliest record of a comet, which is most certainly Halley’s Comet, dating from 240 BC.The Bayeux Tapestry, needlework representing the Norman invasion and the Battle of Hastings in 1066, featured Halley’s Comet. People thought the comet was an omen because it appeared out of nowhere. The tapestry depicts one of King Harold’s attendants informing the King of the sight of the ‘comet star’, suggesting it as a bad omen and possibly a portent of God’s vengeance for King Harold’s unjust claim to the English throne.It’s been suggested that Halley’s Comet is indeed the Star of Bethlehem, seen by the Wise Men around the time of Jesus’ birth. According to records, Halley’s Comet was last seen in 12 BC. However, a record of another probable comet was made in 5 BC. This second object remained in the same spot for 70 days without moving, as though hanging over somewhere, probably Bethlehem.Comet Halley’s discoveryObservations of Halley’s comet have been recorded since 240 BCE by astronomers.The records made at that time did not specify any evidence that this was the comet that appeared again and again.This was the case until 1705 when the English astronomer Edmond Halley presented the justification for the comet’s being periodic. Edmond used the rules of motion given by Newton and applied them to comets.Only in 1705 did he publish the synopsis of the ‘Astronomy of Comets’ in which he justified that the gravitational forces of Saturn and Jupiter have an effect on the comets, making them come back every 76 years. He proved that the comet that was observed in 1607 was the same comet that was observed in 1682.At that time, he couldn’t make a model for it. He paired it with another observation that was made in 1531 and, hence, gave the final conclusion that this comet would return after 76 years. Later, the predictions proved to be absolutely correct as, on Christmas Day, 1758, the same comet was observed by an amateur astronomer and a German farmer named Johann Georg Palitzsh.These predictions not only supported Newton’s laws but also, for the first time, proved that some other object is also in the orbit of the Earth.It was the time when it was proved that comets orbit the Earth. The person who made the discovery, after so much hard work, couldn’t live to witness the return of this comet.It was the French astronomer Nicolas Louis de Lacaille who named the comet after Edmond Halley in 1759. Discovering Halley’s orbit was the first comet observed ever in science. Later, many scientists linked this to meteor showers as well.Comet Halley’s characteristicsHalley’s Comet is one of our solar system’s most well-known comets. It has a very eccentric orbit, and it makes an appearance every 75-76 years. It brings amazing sights with it when it makes its appearance!The most prominent feature of Halley’s comet is its tail. The tail always points away from the sun, and can be up to 62,137.12 mi (100,000 km) long! The gas and dust that make up the tail are constantly being blown off by the sun’s heat.Another interesting feature of Halley’s comet is its nucleus. The nucleus is a small, rocky core that measures only about 9.94 mi (16 km) across. Despite its size, the nucleus contains 99% of the comet’s mass!Halley’s comet is also famous for its ‘dirty snowball’ composition. The comet is made up of water ice, dust, and carbon dioxide gas. When it approaches the sun, the ice on the surface begins to sublimate (turn from a solid to a gas). This leaves behind a dusty trail that can be seen by telescopes on Earth.Because the comet revolves around the sun in the opposite direction to the planets, it moves faster in relation to the Earth’s rotation around the Sun. The comet was measured to be moving at 157838.22 mph (70.56 kph) relative to the Earth during its transit in 1910.It is estimated that Halley’s Comet lost 80–90% of its original mass. Each time it passes close enough to the Sun for us to view it, it will undoubtedly shrink in size.Halley’s comet will make its next appearance in 2061. Make sure to mark your calendars!
There is no doubt that Halley’s Comet is the most famous comet.
