21 Interesting Comet Facts – As Large as Towns?
Comets are small celestial bodies that orbit around the sun much as planets do. As they orbit the sun, they leave behind a trail of frozen gas or dust. This frozen gas and dust often look like a tail and are visible to the naked eye. People have been watching comets and how they travel for several decades.
There are thousands of comets within our vicinity that we are not aware about. Considering this, here are some interesting comet facts for kids. We’re sure these comet facts will capture your attention and pique your interest in learning more about comets!
What is a comet?
A comet is a cosmic ball of dust, frozen gases, and rocks that orbits the sun like other planets. They can be of varied sizes and can range from a few miles to the size of a small town or a planet. When planets are made, comets are formed from the leftover gases, rocks, and dust particles. In fact, any space rock can become a comet once it starts orbiting the sun.
Parts of a comet
A comet is usually divided into four parts: the nucleus, the coma, the bow shock, and the tails.
- The nucleus: The solid structure of the comet is known as the nucleus. This is made up of rock, dust, water, and gases. In this, both the gases and water are frozen, giving it an icy texture. These make up the majority of the ‘head’.
- The coma: The gas and dust released by the head are called the coma. They help form a thin atmosphere around the comet. In fact, they can be created by the sun’s gravity or solar wind and often point away from the sun. The coma is made up of water and dust particles since they both evaporate rapidly as compared to rocks that make up the comet.
- The bow shock: The bow shock is very similar to a coma. Besides being made up of dust and water, it comprises the other gases present in the nucleus. The bow shock becomes wider as the comet gets closer to the sun.
- The tail: A comet’s tail is the most visible part of the comet. It is left behind after the comet travels and is made up of gases, dust, water, etc. A tail can be as long as 500 million kilometres!
Naming a Comet
Comets were originally named after the year when they were observed. For example, the comet of 1680. However, as comets can reappear, the same comet gets renamed multiple times. For example, a comet that appeared in 1607 and 1682 was given different names even though it was the same comet. This created confusion.
As a result, a new system was adopted. Since the 20th century, comets have been named after the people who discovered them. For example, Halley’s comet, the most popular comet in history, was named by Edmond Halley. The convection is still followed unless the discoverer decides and wishes to give the comet a different name.
The five most famous comets are:
- Halley’s comet: Halley’s comet was among the first comets to be named. This is, in fact, the most well-predicted comet in the world.
- Shoemaker-Levy 9: Shoemaker-Levy 9 is famous for breaking into more than 20 pieces!
- Hyakutake: Hyakutake comet is nothing more than an ice-blue blob with a giant tail. However, it produced X-rays a hundred times more intense than expected.
- Hale Bopp: Hale Bopp is among the largest comets to be seen from earth, almost 40 kilometres in diameter.
- Borrelly comet: Borrelly comet is among the most recent discoveries. The comet is shaped like a bowling pin, and interestingly, the comet is lopsided!
21 Interesting comet facts
- Comets are often called dirty snowballs. Since most comets are made of frozen gases, dust, and rocks, this name has become a common convention. The frozen gases often resemble ‘snow’ that is not pure white because of the rocks present.
- There are over 3,700 comets. According to NASA, there are currently 3,743 comets that have been spotted. Some of these are spotted regularly – like Halley’s comet – while some were last seen when dinosaurs inhabited the earth!
- A comet’s path of orbit around the sun is different from a planet’s. A planet usually orbits the sun in a circular path. However, a comet usually orbits the sun in an elliptical path.
- Most comets come from one of the two regions. Scientists and astrophysicists believe that most comets come from either the Oort Cloud or the Kuiper Belt. These are found beyond Neptune and Pluto.
- Halley’s comet comes every 75 years. Named after Edmond Halley, the comet is seen once every 76 years. In fact, the comet has been spotted and recorded several times. It was seen in 1531, 1607, 1682, and 1758. It is expected to appear next in 2061.
- Many comets don’t need telescopes to be seen. While some comets may pass as far as 500 million kilometres away from the earth, they can still be seen by the naked eye. This is possible if they have a large head that burns rapidly as it moves.
- Meteor showers, or shooting stars, are also caused by comets. When a comet passes close to the earth, it can break down into large pieces. These pieces are pulled by Earth’s gravity, giving us a ‘meteor shower’.
- Shoemaker Levy-9’s comet is most famous because it broke into 21 pieces due to Jupiter’s gravity. This was recorded by various telescopes around the world and the Galileo probe (spacecraft) that orbited around the planet in 1992.
- Comets can be as large as a town. While comets can be of any size, most comets are the size of a small town, with their diameter in kilometres. In fact, small comets usually burn before they are visible, making it impossible to notice them. As a result, they are often characterised as debris.
- The Hyakutake comet is most famous because it passed just 15 million kilometres away from Earth – the closest any comet has come. It was observed in March 1996 and had a tail of at least 570 million kilometres long!
- Comets can die as well. They can become extinct or explode if they lose their volatile material that is responsible for the comet burning. So, if there is no volatile material, then the comet becomes a normal lump of rock.
- The sun can break a comet. The sun’s gravity is strong enough to reduce all the volatile material in the comet. In doing so, the sun can break the comet into many smaller pieces. This often happens if the comet comes close to the sun.
- The first probe to land on a comet was in 2014! The Philae lander accomplished a landing on a comet in November 2014. The lander travelled for 10 years through the solar system before catching up with the comet 67P/Churyumov–Gerasimenko.
- The Hale Bopp comet was seen for two years. Comet Hale Bopp was the closest to Earth in 1997. This planet was last seen near earth in the Bronze Age, i.e., around 2000 BC! In fact, this comet was so large that it was visible to the naked eye for almost 2 years!
- If the same comet had been observed by two people, then the name of the comet involves both of their names. For example, Alan Hale and Thomas Bopp both saw the same comet and named it. As a result, the comet is now called Hale Bopp.
- The surface of the comet is mostly made of ice! When observed, the surface of a comet is covered with ice. However, this ice is usually not made from water. Instead, it is made up of carbon dioxide, ammonia, methane, and other gases.
- No one knows what is inside a comet. While probes have landed on a comet, we do not know what the inner part of a comet consists of. The surface of the comet is so hard that it has not been penetrated yet.
- Most comets have two tails. One of the tails can be seen with the naked eye and is called the dust tail. The second cannot be seen through the naked eye and is called the plasma tail. The plasma tail, however, can be seen in high-definition photographs.
- It is believed that a comet smashed on earth, in the region that is now part of the Sahara desert. This was confirmed by tiny pebbles found in the desert. In fact, scientists believe that these came from the core. However, this incident happened over 28 million years ago.
- Each comet has its own unique atmosphere. Just like the earth’s atmosphere is made from oxygen and nitrogen, each comet’s atmosphere is made from gases. It is unique to each comet. The atmosphere can grow and diminish depending upon the size of the comet and where it’s travelling.
- It is believed that the first comet was seen in 500 B.C., and Greek philosophers named it ‘komotes’, which means ‘long haired’. Comets were first recorded by Chinese astronomers in 239 BC.
After reading all these facts, you may want to see a comet for yourself! Thankfully, you do not always need expensive equipment to see them. Scientists estimate that you can spot at least one comet every year from the earth. These comets can be seen directly, i.e., through the naked eyes. Kids should continue reading more about comets and other celestial bodies in order to develop a keen interest in the science subject.