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11 Interesting Facts About Comets You Never Knew (2024 Updates)

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Night scene with a comet

Comets are nothing more than frozen leftovers from the creation of our Solar System, but they are wonderful and spectacular to see. Although comets are far away from our planet, we can often view them using telescopes. Occasionally, comets even enter our atmosphere, which causes them to be termed meteors.

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The 11 Interesting Facts About Comets You Never Knew

If you are interested in learning more about comets, you have come to the right place. Here are 11 interesting facts about comets that scientists have discovered over the years:

1. Comets are sometimes called “dirty snowballs” and “cosmic snowballs”

This may sound goofy, but comets are sometimes called “dirty snowballs” or “cosmic snowballs” because they are made up of ice, rock, dust, and gas. This creates a dirty snowball appearance.

Most of the components that go into the comet are remnants of our Solar System’s creation. In other words, comets are sort of like leftovers from our Solar System.

Stars photograph
Image Credit: Piqsels

2. It’s believed that comets are billions of years old

Comets are surprisingly old. In fact, they are ancient. Because comets are made up of the leftovers of our Solar System’s creation, scientists believe that comets are made up of components 4.6 billion years old.

3. Comets follow an elliptical path

Part of what makes a comet a comet is the fact that it follows an elliptical path or orbit. An elliptical path is whenever a large object orbits around the Sun. The Earth and other planets also have an elliptical path.

Because comets follow an elliptical path, comets can be seen time and time again. They follow the same path on a loop, though how fast they orbit the Sun depends on their location. So, scientists are able to predict whenever some comets will be seen again.

Image Credit: Piqsels

4. Some comets have been observed for centuries

Because comets follow an elliptical path, they always come back. Some comets have even been observed for centuries. Halley’s comet, for example, has been observed since 240 BCE, but it may have been observed before and we just don’t know it.

5. Comets are made up of four components

Comets are made up of four components in total, including a nucleus, coma, tail, and an ion or plasma tail.

The nucleus is the center mass made up of ice, dust, and gas. The ice can be made up of different materials, including carbon dioxide, water, methane, and ammonia.

As comets approach the Sun, that ice from the nucleus begins to turn into a gas state. The dust then forms around the nucleus. That surrounding dust is called the coma. Coma materials get swept to the tail, the third component.

The tail is the trail of dust and gas behind the nucleus. There are two different types of tails: the dust tail and the plasma tail. The plasma tail is the fourth component. It often is blue due to how hot it is.

woman watching stars using telescope
Image Credit: Allexxandar, Shutterstock

6. The Sun affects comets drastically

As we’ve already covered in some detail, the Sun affects comets drastically. The comet’s tail is only developed because of the heat from the Sun. The Sun’s heat is so strong that it causes the ice to turn into gas, skipping the liquid stage in between. This is what creates the tail of the comet.

7. Comets are often miles across

In order for us to see comets, they have to be pretty big in comparison to us. Comets are normally anywhere from 1–10 kilometers. That is about 0.6–6 miles in size. Even though these comets may seem big to us, they are actually pretty small in comparison to the entire Solar System.

people watching comet
Image Credit: Jim Cumming, Shutterstock

8. Comets come from different locations

Comets come from different locations in our Solar System. Some comets live within the Kuiper belt of Neptune. These comets are called short-period comets. Short-period comets only take 200 years or less to orbit the Sun.

In contrast, some comets live in the Oort cloud. These comets are called long-period comets. Some comets can take as long as 250,000 years to go around the Sun.

9. Over 3,000 comets have been observed

You might think that comets are rare, but that is not really the case. As of 2022, scientists at NASA have confirmed 3,743 comets, but they predict there are likely billions of comets. Some are either too far away for us to observe or are too small.

Person looking through telescope
Image credit: AstroStar, Shutterstock

10. A meteor is different from a comet

When discussing comets, there are a lot of terms used interchangeably, such as comet and meteor. Although comets and meteors are related, they are not the same. A meteor is a comet that has entered our atmosphere, whereas a comet has not.

Likewise, a meteor shower happens whenever our atmosphere runs into the tail of the comet, creating a snowy-like effect in the sky.

11. Comets are named after the person who discovers them

Comets are named, but they aren’t named randomly. Instead, comets are named after the person who discovers them. Halley’s comet, for example, was discovered by astronomer Edmund Halley.

man watching stars using telescope
Image By: True Touch Lifestyle, Shutterstock

telescope divider 1 How Are Comets Formed?

Unfortunately, we don’t know for certain how comets are formed, but scientists have some theories. Most scientists believe that comets are made up of the dust and gas of protoplanetary disks, which are clouds of debris that surround a new star. These materials are about 4.5 billion years old.

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As these 11 facts show, there’s a lot to learn about comets. Even though we covered some of the most interesting facts here, there is still a lot more to learn. We recommend reading up further on comets so you can fully understand where they are from, how they function, and how you can see one from our planet.

Featured Image Credit: Triff, Shutterstock

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.