Magicis Stellarum et Plantae
written by Katherine Lutz
Astronomy textbook. - Second edition
Last Updated
05/31/21
Chapters
15
Reads
1,356
Asteroids, Meteors, and Other Celestial Bodies
Chapter 12
There are many celestial bodies besides planets and moons traveling around the Sun. This includes asteroids, filling the space between Mars and Jupiter. There are meteoroids that turn into meteors and rain down to the Earth, putting on a magnificent spectacle. There are comets (giant snowballs whizzing past the Sun), and many other icy objects far away in both the Kuiper belt and Oort cloud. All of this is found without ever having to step foot beyond our Solar System.
10 a. Asteroids
Asteroids are basically big rocks that are orbiting the Sun. They are not large enough to be round, or to clear their neighborhoods of other large bodies, therefore they are not classified as planets. The majority of asteroids are remnants left over from the formation of our Solar System. Asteroids are known to range from less than 1 kilometer to 952 kilometers in width. The largest asteroid is the dwarf planet Ceres. There are over half a million asteroids that have been discovered, and there are most likely many more in our Solar System waiting to be seen. They are usually irregularly shaped, although the more massive asteroids can be nearly round.
10 b. The Asteroid Belt
When our Solar System was still in its early stages, the formation of Jupiter caused all of the small celestial bodies occupying the space in between itself and Mars to collide with one another, and break into millions of pieces. This area became known as the asteroid belt, and it is home to the majority of the asteroids in our Solar System. Sometimes Jupiter’s gravity sends asteroids hurtling out into space, and they have even been known to hit Earth. There are Muggle groups in charge of monitoring asteroids that might cross Earth’s orbit, as a collision can cause huge damage and destruction.
10 c. Meteoroids
Meteoroids are small rocks that range in size from as large as a boulder to as small as a grain of sand. They have been found to be composed of many different substances. Some meteoroids are made of snow or ice, while others are made of dense nickel and iron. Meteoroids travel in orbit around the Sun, and their speed can vary, although most are quite fast; the fastest can travel at 42 kilometers per second.
10 d. Meteors
Once a meteoroid enters the Earth’s atmosphere, it is referred to as a meteor. When meteors enter the mesosphere layer of the Earth’s atmosphere, they leave a visible trail behind themselves as they fly across the sky. Meteors are visible from Earth when they are between 65 and 120 kilometers above the planet.
Meteors are better known as shooting stars, to both wizards and Muggles alike. On an average night, it is possible to see a couple of meteors per hour, assuming that the conditions are clear, and there is no light pollution. To view meteors, it is best to get away from the city, or if you are in the country, to turn off all outside lights. Even glancing at a light source for a second can ruin your night vision for a few minutes, decreasing the probability of seeing that one stray meteor. It is also wise to go meteor watching on nights when a new moon or thin crescent moon is present. The full moon can produce just as much light pollution as having all of the outside lights of your house switched on, which is not ideal for watching meteors. A cloudy sky can also prevent you from seeing any meteors, for obvious reasons.
10 e. Meteor Showers
Even with absolutely perfect conditions outside, is it really worth planning a trip to the country for one or two shooting stars? Maybe not, but you are in luck. Many meteors also travel in groups, called showers. Meteor showers occur when the Earth passes through debris left over from a comet. The meteors all appear to radiate from a specific point in the night sky. There are over 50 meteor showers known to astronomers, some of which occur around the same time every year. Some meteor showers are not much better then what you could see on an average night of sky watching, and some even occur during the day. However, there are other showers where it is possible to see over a hundred meteors in an hour. These are spectacular shows, and definitely worth your time to watch.
Meteor showers are named after the constellation from which they appear to originate. When watching a meteor shower, all of the meteors will appear to come from a certain point, but it is not necessary to know where the constellation is in the sky; all that matters is having a clear view of the sky. Meteor showers are amazing astronomical events that can be appreciated by even the most amateur astronomer. All that you need to take in the sights are your own two eyes. The main meteor showers will be highlighted below, with approximate peak dates. Most meteor showers can last for weeks at a time, but there are usually specific days where the meteors are at their most frequent. The peak dates change every year, so it would be wise to check before going outside, to make sure that you are not a week late or early. Most showers peak for one or two nights.
Picture
In all cases, the largest amounts of meteors are visible in the early hours before dawn, usually about 2 to 4 a.m. local time. In general, the showers to watch for the best displays are the Perseids and Geminids, but surprises are always a possibility.
10 f. Fireballs
Fireballs are super bright meteors, even brighter than the visible planets. The Leonid meteor shower is well known to have fireballs. Another name for a fireball is a bolide.
10 g. Meteorites
A meteorite is a piece of a meteoroid, a comet, or an asteroid that survives its trip through Earth’s atmosphere, and lands on the ground intact. Meteorites are able to show us the composition of bodies beyond Earth, and apart from some Moon rocks brought back from the Apollo missions, they are our only samples of extraterrestrial substances. Meteorites can be made of many different elements. Larger meteorites can cause huge craters upon impact with the Earth. It is even thought by some Muggle scientists that the impact from an asteroid or comet is what caused the extinction of the dinosaurs 65 million years ago.
10 h. Comets
Comets are celestial snowballs, made of frozen gasses, rocks, and dust. They are often rather large, ranging from 100 meters to more than 40 kilometers across. Sometimes the orbit of a comet can bring it close to the Sun. When this happens, the comet heats up and sends dust and gas spewing in all directions. This forms a large glowing head, bigger than most planets. It also creates a tail that can stretch for millions of kilometers across the sky.
Comets are leftovers from the birth of our Solar System. They consist of a nucleus (made of ice chunks, frozen gases, rocks, and dust), a core of ice, and a coating of a dark, organic substance. Some Muggle scientists think that comets might have brought water and the basic organic compounds necessary for life to the Earth, although this has not been proven. Most comets originate in the Kuiper belt, which is estimated to hold at least a trillion comets. These are called short-term comets, as they only take about 200 years to orbit the Sun. Their paths are fairly predictable. Other comets originate in the Oort cloud. These are called long-term comets, because they have highly eccentric orbits, and can take thousands of years to orbit the Sun.
10 i. The Kuiper Belt
The Kuiper belt is the disk-shaped region filled with icy bodies, located beyond Neptune’s orbit. It is located billions of kilometers away from the Sun, and is home to the majority of known dwarf planets, with most likely hundreds more dwarf planets and other celestial bodies waiting to be discovered. Its distance ranges from about 30 AU to 55 AU from the Sun.
10 j. The Oort Cloud
The Oort cloud is a hypothetical spherical area full of icy bodies that is surrounding our Solar System. It is believed to fill up the space from anywhere between 2,000 AU to 50,000 AU from the Sun. The influence of the Sun on the outer edges is weaker than the influence of other stars. There are possibly 2 trillion icy objects in the Oort cloud. Sometimes passing stars, or interactions with the Milky Way, can cause bodies to be sent flying to the inner part of the Solar System. These are called long-term comets. The Oort cloud marks the outer boundary of our Solar System.
10 a. Asteroids
Asteroids are basically big rocks that are orbiting the Sun. They are not large enough to be round, or to clear their neighborhoods of other large bodies, therefore they are not classified as planets. The majority of asteroids are remnants left over from the formation of our Solar System. Asteroids are known to range from less than 1 kilometer to 952 kilometers in width. The largest asteroid is the dwarf planet Ceres. There are over half a million asteroids that have been discovered, and there are most likely many more in our Solar System waiting to be seen. They are usually irregularly shaped, although the more massive asteroids can be nearly round.
10 b. The Asteroid Belt
When our Solar System was still in its early stages, the formation of Jupiter caused all of the small celestial bodies occupying the space in between itself and Mars to collide with one another, and break into millions of pieces. This area became known as the asteroid belt, and it is home to the majority of the asteroids in our Solar System. Sometimes Jupiter’s gravity sends asteroids hurtling out into space, and they have even been known to hit Earth. There are Muggle groups in charge of monitoring asteroids that might cross Earth’s orbit, as a collision can cause huge damage and destruction.
10 c. Meteoroids
Meteoroids are small rocks that range in size from as large as a boulder to as small as a grain of sand. They have been found to be composed of many different substances. Some meteoroids are made of snow or ice, while others are made of dense nickel and iron. Meteoroids travel in orbit around the Sun, and their speed can vary, although most are quite fast; the fastest can travel at 42 kilometers per second.
10 d. Meteors
Once a meteoroid enters the Earth’s atmosphere, it is referred to as a meteor. When meteors enter the mesosphere layer of the Earth’s atmosphere, they leave a visible trail behind themselves as they fly across the sky. Meteors are visible from Earth when they are between 65 and 120 kilometers above the planet.
Meteors are better known as shooting stars, to both wizards and Muggles alike. On an average night, it is possible to see a couple of meteors per hour, assuming that the conditions are clear, and there is no light pollution. To view meteors, it is best to get away from the city, or if you are in the country, to turn off all outside lights. Even glancing at a light source for a second can ruin your night vision for a few minutes, decreasing the probability of seeing that one stray meteor. It is also wise to go meteor watching on nights when a new moon or thin crescent moon is present. The full moon can produce just as much light pollution as having all of the outside lights of your house switched on, which is not ideal for watching meteors. A cloudy sky can also prevent you from seeing any meteors, for obvious reasons.
10 e. Meteor Showers
Even with absolutely perfect conditions outside, is it really worth planning a trip to the country for one or two shooting stars? Maybe not, but you are in luck. Many meteors also travel in groups, called showers. Meteor showers occur when the Earth passes through debris left over from a comet. The meteors all appear to radiate from a specific point in the night sky. There are over 50 meteor showers known to astronomers, some of which occur around the same time every year. Some meteor showers are not much better then what you could see on an average night of sky watching, and some even occur during the day. However, there are other showers where it is possible to see over a hundred meteors in an hour. These are spectacular shows, and definitely worth your time to watch.
Meteor showers are named after the constellation from which they appear to originate. When watching a meteor shower, all of the meteors will appear to come from a certain point, but it is not necessary to know where the constellation is in the sky; all that matters is having a clear view of the sky. Meteor showers are amazing astronomical events that can be appreciated by even the most amateur astronomer. All that you need to take in the sights are your own two eyes. The main meteor showers will be highlighted below, with approximate peak dates. Most meteor showers can last for weeks at a time, but there are usually specific days where the meteors are at their most frequent. The peak dates change every year, so it would be wise to check before going outside, to make sure that you are not a week late or early. Most showers peak for one or two nights.
Picture
In all cases, the largest amounts of meteors are visible in the early hours before dawn, usually about 2 to 4 a.m. local time. In general, the showers to watch for the best displays are the Perseids and Geminids, but surprises are always a possibility.
10 f. Fireballs
Fireballs are super bright meteors, even brighter than the visible planets. The Leonid meteor shower is well known to have fireballs. Another name for a fireball is a bolide.
10 g. Meteorites
A meteorite is a piece of a meteoroid, a comet, or an asteroid that survives its trip through Earth’s atmosphere, and lands on the ground intact. Meteorites are able to show us the composition of bodies beyond Earth, and apart from some Moon rocks brought back from the Apollo missions, they are our only samples of extraterrestrial substances. Meteorites can be made of many different elements. Larger meteorites can cause huge craters upon impact with the Earth. It is even thought by some Muggle scientists that the impact from an asteroid or comet is what caused the extinction of the dinosaurs 65 million years ago.
10 h. Comets
Comets are celestial snowballs, made of frozen gasses, rocks, and dust. They are often rather large, ranging from 100 meters to more than 40 kilometers across. Sometimes the orbit of a comet can bring it close to the Sun. When this happens, the comet heats up and sends dust and gas spewing in all directions. This forms a large glowing head, bigger than most planets. It also creates a tail that can stretch for millions of kilometers across the sky.
Comets are leftovers from the birth of our Solar System. They consist of a nucleus (made of ice chunks, frozen gases, rocks, and dust), a core of ice, and a coating of a dark, organic substance. Some Muggle scientists think that comets might have brought water and the basic organic compounds necessary for life to the Earth, although this has not been proven. Most comets originate in the Kuiper belt, which is estimated to hold at least a trillion comets. These are called short-term comets, as they only take about 200 years to orbit the Sun. Their paths are fairly predictable. Other comets originate in the Oort cloud. These are called long-term comets, because they have highly eccentric orbits, and can take thousands of years to orbit the Sun.
10 i. The Kuiper Belt
The Kuiper belt is the disk-shaped region filled with icy bodies, located beyond Neptune’s orbit. It is located billions of kilometers away from the Sun, and is home to the majority of known dwarf planets, with most likely hundreds more dwarf planets and other celestial bodies waiting to be discovered. Its distance ranges from about 30 AU to 55 AU from the Sun.
10 j. The Oort Cloud
The Oort cloud is a hypothetical spherical area full of icy bodies that is surrounding our Solar System. It is believed to fill up the space from anywhere between 2,000 AU to 50,000 AU from the Sun. The influence of the Sun on the outer edges is weaker than the influence of other stars. There are possibly 2 trillion icy objects in the Oort cloud. Sometimes passing stars, or interactions with the Milky Way, can cause bodies to be sent flying to the inner part of the Solar System. These are called long-term comets. The Oort cloud marks the outer boundary of our Solar System.
