What’s The Difference Between Asteroids, Comets, And Meteors?

Asteroids, comets, meteors, and meteorites are all words that seem interchangeable, but they are not!

What's The Difference Between Asteroids, Comets, And Meteors

Whilst they do have similarities, it’s a good idea to get to know the differences between them when trying to accurately detail or describe the night sky.

So, what’s the difference? Below is a brief description of each, and what the word actually means in terms of the objects themselves.

Asteroid

What's The Difference Between Asteroids, Comets, And Meteors?

An asteroid is a small rocky body orbiting the Sun. There are many different types of asteroids, from the very large (like Ceres) to the tiny ones with diameters less than 1km.

The largest object known to be an asteroid is Ceres which is about 950km across.

The majority of asteroids are made up of rock, iron, and other minerals. They can be as large as several hundred kilometers across, but most are only around 100 meters wide.

Meteor

A meteor is a piece of rock or metal that enters Earth’s atmosphere at high speed and burns up as it falls back down to Earth. It may look like a ‘shooting star’ or ‘fireball’.

The term meteor actually refers to the burning ‘tail’ that we see in the sky. Most meteors burn up before reaching the surface, although some survive long enough to reach the ground.

When a meteor reaches the Earth’s atmosphere, it slows down due to friction with air molecules. This causes its temperature to rise until it becomes incandescent.

As the object continues to fall towards the Earth, the heat from the burning material increases and the resulting pressure pulls the object apart into smaller pieces known as meteorite fragments.

Meteorite

Meteorite

A meteorite is a piece of debris from a meteor that has survived atmospheric entry and landed on Earth. It may contain rocks, dust, metal, glass, ice, organic matter, and even living organisms.

Many meteorites are found deep within Earth’s crust where they were formed over billions of years. Some meteorites are very old, having been created millions of years ago.

Comet

Comet

A comet is a celestial object that orbits the sun in a highly elliptical orbit. Unlike asteroids, comets don’t have any solid surface; instead, they are mostly composed of frozen gases.

Although they appear to move slowly across the sky, comets travel much faster than the planets. Because their orbit takes them close to the sun, comets become extremely hot, causing them to glow brightly.

Like an asteroid, comets can be made of ice and rock, although some comets contain more exotic materials such as carbon, silicon carbide, iron, and even gold.

Some comets can be quite big – Halley’s Comet has been known to reach a diameter of over 2,000 kilometers.

Meteor Shower

Meteor Showers

A meteor shower occurs when many meteors enter Earth’s atmosphere simultaneously. This results in numerous bright streaks of light in the sky lasting for seconds to minutes.

The best time to view one is during the early hours of the morning or late evening.

How Do I Know If I’m Seeing A Meteor?

The easiest way to tell if you’re seeing a meteor is by looking out for the streak of light. You should try to watch the sky for 10–15 minutes before dawn or dusk.

Look towards the horizon where the Moon will set. If you see a streak of light moving away from you then you’ve probably seen a meteor.

What Are The Different Types Of Meteor Showers?

There are three main types of meteor showers – fireballs, bolides, and Orionids. Each type of meteor shower is caused by a particular celestial body.

Fireball

Fireballs occur when a meteorite breaks apart in Earth’s atmosphere and its fragments burn up as they descend.

Fireballs are sometimes mistaken for meteors because they appear similar to falling stars. However, unlike meteorites, fireballs do not leave any trace behind.

Bolide

Bolides are the result of large meteorites breaking apart in Earth’s air. They are very rare events but have been observed several times since the 19th century.

Orionid

The Orionids are produced by the breakup of a comet. They are named after the constellation Orion.

When Will I See A Meteor Shower?

Meteor Shower

You might be lucky enough to witness another meteor shower in your lifetime. Two major meteor showers occur – Perseids and Leonids.

Both of these showers happen around the same time each year (August) and both produce lots of meteors.

Perseids

The Perseids are produced by the comet Swift-Tuttle. It was discovered in 1862 and it returns every 133 years. When it does return, it produces about 50 meteors per hour.

Leonids

The Leonids are produced by the Comet Tempel-Tuttle. This comet was discovered in 1866 and it returns every 33 years. When it does come back it can produce anywhere between 100 and 200 meteors per hour.

There are a lot of other showers that occur so it’s a good idea to be on the hunt for news of it so you can get prepped and ready for these rare events!

What Happens To The Debris From A Meteor?

A meteoroid is a small part of a meteor that burns up in the atmosphere. Most of the material falls into the ocean or lands on land. Sometimes this material gets picked up by satellites and spacecraft.

By the time these small chunks of rock and debris reach Earth (if at all) they are usually as small as a pebble, or a grain of sand and dust.

Where Does All Of The Dust Come From?

Meteor dust comes from space. Space is filled with many different particles including asteroids, comets, and meteoroids. Some of these particles enter our atmosphere at high speeds.

Once they reach the top of the atmosphere they begin burning up. During this process, they release energy and create a trail of debris.

How Do We Know What Causes These Things?

Astronomers study all of this stuff using telescopes. Telescopes help us to understand the universe better and we use them to figure out what happens in space.

The most common way astronomers look at things in space is called spectroscopy. Spectroscopy allows scientists to identify objects based on the light that they emit.

For example, if an object has a red color then it must be made of iron. If it has a green color then it must be oxygen.

Another way astronomers observe things in space is called imaging. Imaging uses telescopes to take pictures of distant objects. Astronomers use these images to learn more about the objects.

What Is A Meteorite And Where Are They Found On Earth?

Meteorite

A meteorite is a solid chunk of rock or metal that comes off another planet or celestial body. They are formed when a meteoroid – a small particle of matter – collides with another object.

This collision creates a crater in the target object, ejecting material into space. Over time this ejected material can fall to Earth as a meteorite.

What Are Meteorites Made From?

Well, they are mostly made of material from the outer parts of the solar system, which means they are mainly composed of rocky elements.

However, some meteorites have been found to contain other types of material, including metals (such as gold) and organic compounds (like amino acids).

Where Do Meteorites Come From?

Most meteorites originate from asteroids. An asteroid is a large rocky body orbiting the sun. Sometimes, asteroids collide with each other, causing fragments to break off and become meteorites.

Other times, asteroids may get hit by larger objects like planets. In either case, the resulting meteorite is very similar to its parent asteroid.

Are All Meteorites Valuable?

No! Not all meteorites are worth anything. There are thousands of different kinds of meteorites, but only a few of them are rare enough to be considered valuable.

For example, the famous Vesta meteorite was discovered in 1807 and it contains minerals that were important to understanding our solar system. It is now valued at around $1 million.

What Makes A Meteorite Rare?

Rareness depends on the type of meteorite. Some are very common, while others are extremely rare.

Most meteorites are not classified as “rare” because there are so many of them. But certain ones are much harder to obtain than others.

Final Thoughts

This is just a basic overview, so do some more research and involve yourself in local astronomy groups to find out more!

If you are lucky enough to live near to a science or space museum, have a look around, as they will have examples of meteorite fragments on display so you can see some space rock firsthand!

Gordon Watts