A meteor has a name change once it enters the atmosphere of Earth. It’s then known as a “meteoroid” or a “space rock.” When it flies through the atmosphere it meets the resistance and begins to heat up.
When we see these at night we call them “shooting stars.” Whether the Earth crosses the path of a large group of meteors or a group makes its way to Earth, it’s called a “meteor shower.”
Most meteor showers are the result of a comet passing by or even breaking up. When a comet is doing a fly by it loses some of its mass and the pieces become part of a meteor shower.
Although a lot of comets do have a standard or regular orbit, once it begins to break up it becomes lots of different pieces that are scattered. A comet has a limited life cycle because each time it gets near the sun it loses some of its water, gasses, and dust.
That process can be seen as the comet’s “tail.” Over a period of time the comet will get smaller and smaller until it finally falls apart and the debris is thrown out along its path.
As Earth travels around the sun it often hits areas where there is a lot of leftover debris from comets that have died. During those times we have exciting visual displays in the sky as meteor showers.
Meteor Shower Statistics:
Meteoroids are typically rather small and range in size from a little dust particle all the way to the size of a boulder. A majority of the meteoroids burn up as they enter the atmosphere of Earth and the process of burning up creates the shooting stars that we see at night.
Scientists believe that around 48.5 tons/44,000 kg of materials from meteors fall on the surface of the Earth every day. On any night you can usually look up and see at least a few meteors every hour.
Meteor showers can happen on a regular annual basis when the Earth passes through a path where a comet has left a trail of debris.
Astronomers have made note of the times of the year that meteor showers can occur and a lot of people go out to areas that have very little light from the cities or towns so that they can watch them.
One of the most well-known meteor showers are the Perseids that happen every August. Each piece of the Perseid meteor is a small bit of the Swift-Tuttle comet that passes by the sun every 135 years.
The various pieces of the meteors enter the atmosphere at angles, but when you are looking at them from Earth they appear as if they are all coming from the same point.
This point is referred to as the “radiant,” and it’s called that because the meteor shower looks like it radiates from one point in the sky.
Some of the most intense meteor showers are known as “meteor outbursts and meteor storms,” and these can produce as many as 1,000 or more meteors in an hour.
There are meteor showers that have been known for hundreds of years and various civilizations prepare to watch them from their position on the Earth at the specific times that they will show up in the sky.
Other planets that have a transparent atmosphere can also have meteor showers.
Mars is one planet that we know experiences meteor showers. The meteors that Mars passes through are different than those that the Earth passes through due to the different orbits of the planets.
Meteor Shower Names:
Meteor showers are named after the constellation that they occur in. The Leonids meteor shower is named after the Leo constellation, the Perseids is named after the constellation Perseus, and the Orionides meteor shower is named after the constellation Orion.
Meteor Showers in Ancient Times:
Many ancient cultures kept good records about the things that happened in the sky. Historical texts have been found from China, Korea, and Japan that noted meteor showers.
The first records that have been located that noted a meteor shower observation was in 36 AD in the Han Chinese records for the Perseid meteor shower. The astronomers in China kept their records by writing them in ink on silk.
Early astronomers of the Near East kept incredible records for celestial happenings as well as calendars.
Scientists that have studied ancient Babylonia records called “cuneiform texts” have discovered that the astronomers tracked the planetary movements, comets, and all events of the sky as far back as the first millennium BC.
Throughout history, people thought that objects such as meteors, comets, and even meteor showers were signs of good or bad luck from the gods that they worshipped.
Both the Romans and the Greeks thought that these celestial objects were a kind of prediction about something that was good or bad. They believed that comets was to bring about the birth of someone that would be great.
In 44 BC a comet showed up right after Julius Caesar was killed and the people took it for a sign that he was supposed to be made into a god.
Cassius Dio, a Roman historian, talked about meteor showers as “comet stars” in 30 BC. They are mentioned as omens after Cleopatra, the Queen of Egypt had died.
In the Christian religion, the Perseid meteor shower is associated with the martyrdom of St. Lawrence, a deacon of the early church that died in 258 AD.
When the martyrdom occurred the meteor shower was at its strongest and they thought it was the tears of the saint.
In some circles, they believe that the arrival of the Persian Magi to Bethlehem was due to a comet that they followed in the sky and not an actual star.
Comets are often called “dirty snowballs” because they are made up of ice that can be water, methane, ammonia, or other materials, as well as dust and metals. The “rock” portion can be as small as a piece of dust or as large as a small boulder.
When a comet travels in the far distance of space it is cold, however, as soon as it gets near the sun everything starts heating up. Ice can quickly become steam, and the vapor will take pieces of the dust and pebbles along with it as it streams out.
Every time a comet’s orbit swings by the sun a bit of the ice vaporizes and some of the mass will be thrown out with it. The pieces of meteoroid are left in the trail that the comet has taken and this is called a “dust trail.”
Most of these pieces are so small that solar radiation blows them away. Those pieces that stay within the path of the comet can become part of a meteor shower when they enter an atmosphere.
Meteor showers often include what are called “fireballs.” This is a word for an extremely bright meteor which is around the same brightness as the planet Venus when you see it in the night or morning sky.
A “bolide” is a unique form of fireball that ends in a bright explosion in the night sky and usually has pieces falling that you can see.
Schedule of Known Meteor Showers:
- January: Quadrantid maximum is a short but very intense meteor shower, with an average of about 20 sightings per hour. Many of the radiants are spread from ecliptic Cancer to Virgo.
- February through April: The evenings often have an unusual number of “fireballs.”
- Mid-April: The Lyrids occur for several nights.
- May: The Eta Aquariids for the first half of May.
- July: The Delta Aquariids and the Alpha Capricornids occur.
- Late July through Mid-August is one of the best times of the year for meteor showers. This is when Perseid maximum begins and continues through mid-August.
- Mid-September to mid-December: Sporadic meteor showers occur.
- Mid-October to mid-December: Meteor activity is heavy, with the Orionids in the second half of October and the Taurids from October into November. The Taurids often have a number of fireballs each night.
- Mid-November: The Leonids are usually very strong but often unpredictable. However, it gains in strength for a strong show every 33 years.
- Mid-December: The Geminids are the most dependable and the strongest meteor shower of the year, often having 60-70 per hour maximum.
- End of December: The Ursids end the year with an often forgotten but excellent show.
- Some meteor showers occur from what are called “sporadic meteors.” These are meteors that are from random meteors that are flying through space as a result of being a leftover from the creation of the solar system.
- Meteor showers are more active in the northern hemisphere of Earth. People living in the northern hemisphere will see more meteor showers than those in the southern hemisphere.
- When observing a meteor shower from the southern hemisphere (below the equator), the meteors look like they are traveling in an upward direction.
- There are some meteor showers that are viewed better from the southern hemisphere and usually occur in the months of July through September. They include: Alpha Centaurids, Gamma Normids, Pi Puppids, Piscis Austrinids, Delta Aquarids, Alpha Capricornids, Dec Phoenicids, and the Puppid/Velids.
- If anyone sees a “fireball” or a group of fireballs with a meteor shower, the American Meteor Society requests that you report the information to them.
- There are several famous and easy-to-observe meteor showers. The Perseids occur in mid-August when Earth encounters the debris trail from Comet Swift-Tuttle. They appear to radiate from a point in the constellation Perseus. The shower lasts from mid-July to late August, with a peak around August 12th each year.
- The Leonid meteor shower can be a very busy one. It occurs each year in mid-November, and rains debris from Comet 55P/Tempel-Tuttle. In 1833, observers estimated that hundreds of thousands of meteors flared through the sky. Observers wait for it each year, hoping for another spectacular show, emanating from the direction of the constellation Leo.
- The Geminid meteor shower occurs in December, when Earth crosses the path of the asteroid 3200 Phaethon. The meteors appear to come from the direction of the constellation Gemini, and observers have noted that they move more slowly than other meteors.
- In late April, the Lyrids bring pieces of comet C/1861 G1/Thatcher back to Earth, which seem to radiate from the constellation Lyra. The peak of this storm is around April 22. Every 60 years or so this shower becomes more intense.
Facts about Meteor Showers for Kids:
- Most meteor showers are caused by debris from comets. When Earth moves through those debris trails, we see increased numbers of comets.
- Two meteor showers are caused by debris shed by asteroids. The Quadrantids are very likely caused by debris from the minor planet 2003 EH1. The Geminid meteor shower comes from debris shed by asteroid 3200 Phaethon.
- The Orionid Meteor shower (which occurs in late October each year) is created by dust and debris left behind by the passage of Comet 1P/Halley.
- Meteors fall to Earth during the day, although we can’t see them.
- It is very rare that a meteorite will strike a human being. It’s more likely that it will fall into the ocean.
- The best time to view a meteor shower is in the early morning hours, preferably on a dark, moonless night.
- The earliest record of the Perseids meteor shower is found in Chinese annals from 36 AD.