One of these amazing Celestial events involving meteors, meteoroids or meteorites is ‘The Meteor Shower’, and the once considered in many ways to be the best, are the Perseid meteor showers.
So let’s take a look at one of the better-known meteor showers that radiates from our night sky into the Earth’s atmosphere, and is associated with the Constellation Perseus.
The Perseid Meteor Showers
Asteroids, Comets and Meteors are regarded as the leftovers following the formation of our Solar System, some 4.6 billion years ago. They have not changed over time and remain a fossil-like reminder of our planetary evolution.
Before we can describe the facts around meteor showers we need to understand what they are and the difference between a Meteoroid, a Meteor and a Meteorite?
Their similar names can be a little bit confusing, but basically these three names are used to describe the same object depending on where it is. Each is part of a process that occurs when an object from Space falls to Earth, while in orbit they are called meteoroids, as they travel into the Earth’s atmosphere they are called Meteors and if they make contact with Earth they become meteorites:
– Is a small fragment of rock, or iron, from outer Space (that is either a meteoroid or asteroid), which does not disintegrate as it enters the Earth’s atmosphere as a meteor?
When it falls and impacts the surface of the Earth it is called a Meteorite. Meteorites can be Stony meteorites, Iron meteorites or Stony-iron meteorites
– Is a Meteoroid (a space rock) that has entered the earth’s atmosphere and vaporized into a meteor (or shooting star)
As the Meteoroid rapidly travels towards Earth through the Earth’s atmosphere the drag, or resistance, as it passes through the air causes friction making it become very hot.
These bright Meteors, or meteor streaks, that light up the sky as they travel rapidly are what’s known as ‘Shooting Stars’ or ‘Fireballs’. The part of the Shooting Star known as the bright meteor streak or the flaming tail is one of the top sights when stargazing.
It is a common image associated with a shooting star, although is not part of the rock itself, in fact it is the glowing hot air left by the hot rock as it travels through the earth’s atmosphere towards our Planet Earth. When several Meteoroids encounter Earth at the same time it is known as a Meteor Shower.
When this Meteor finally makes contact with the Earth it’s known as a Meteorite.
The ancient names for a Meteor:
- Meteorum – from Latin
- Meteoron – from Ancient Greek
- Metheour – from old English language
- Meteore – from old French Language
The early naming of this astronomical phenomenon involves the combination of the word “meta’ meaning high in the air, and a version of the word ‘aoros’ meaning to lift up.
Ancient civilizations have been seeing Meteors for thousands of years. Some believed the Shooting Stars and Fireballs were powerful and messages of doom, or warnings from their deities (gods).
Our inner Solar System
What is happening in the inner solar system where we live?
Within the inner solar system there is much activity and several of the largest objects regularly orbit the Sun. When a planet like Earth passes the Sun in orbit it is in a fairly circular orbit, however when Comets orbit the Sun the route is often lop-sided.
Not all Planets orbit the Sun, for example Jupiter, which is the largest Planet and has the shortest day in the solar system (of only 10 hours), does not orbit the Sun.
This is confirmed by NASA in its studies using the Juno spacecraft and seen by many scientists using the Earth-orbiting NASA Hubble Space Telescope.
As Comets travel closer to the Sun some of the icy surface melts off and particles of rock and dust are released into orbit. As the Comet continues to travel this space debris is spread along the trail of the Comet littering our inner solar system.
Our Planet Earth orbits the Sun several times a year and when its orbit crosses the orbit of a Comet it crashes into the space debris left by Comets, which form Meteoroids.
Meteoroids are not the largest objects in Space in fact they are usually small, ranging from a small dust particle up to the size of a boulder. It is unlikely that any will actually strike Earth as they usually burn up in the Earth’s atmosphere first.
The Perseid Meteor Showers– Facts in brief:
What is it? –
The Perseid meteor showers are an annual event that takes place when the earth travels through a particular part of it’s annual orbit of the sun. In this region, there is exists the remnants of an old comet and this is what created the meteor shower as debris falls to earth, visible in the direction of the constellation Perseus.
It is possible for sky watchers to see an amazing shooting star event in the middle of the night and through the pre-dawn hours in clear skies.
City lights and pollution can negatively affect the visibility of meteor showers and the brightness of a full moon can dampen the visibility.
What’s special about the Perseids?
There are lots of factors that distinguish The Perseids from the other named annual Meteor showers.
They’re the Best
- The Perseids are considered the best meteor shower in the night sky and are visible in the Northern Hemisphere from as early at 22.00, local time.
They’re the Brightest
- They are also much brighter, displaying an apparent magnitude greater than -3. They are recognized for the way they leave ‘long wakes’ of light and color behind them as they race across the sky.
They’re the most active
- With an average of 50-100 meteors seen per hour this makes them one of the most plentiful showers we can see in the summer night skies. This is indeed a treat for any level of sky watcher.
They exhibit amazing explosions of light and color known as Fireballs.
The Fireballs emitted from The Perseids are larger and last longer than the average meteor streak across the sky as they come from larger pieces of Comet surface shedding.
Where do they come from?
It is the bits of space debris, possibly coming off a Comet that is the source of the Perseids.
The Perseids occur the thanks to floating debris from the Comet 109P/Swift-Turtle. This Comet is large with a nucleus 16 miles across (26 kilometers)
The Perseid association with the Constellation Perseus
It is the Constellation Perseus that gives the Perseid meteor showers their name. The Perseus Constellation is named after Perseus who was a popular character from Greek mythology.
The Perseus Constellation is one of the oldest known constellations, and ranks as the 24th largest Constellation as one of the original 48 Constellations listed by Greek Astronomer Ptolemy, in the 2nd century.
Perseus is one of the official International Astronomical Union (IAU) listed 88 modern constellations as seen in the night sky from Earth.
Perseus (its Latin name) is quite easy to recognize, as it clearly resembles the outline of this Greek Hero holding the severed head of Medusa, the Gorgon Medusa, in his hand.
Where is the Perseus Constellation located? –
Constellation Perseus is positioned in the first quadrant of the Northern Hemisphere, north of the ecliptic. It is sometimes referred to as being located in the NQ1 Quadrant.
FACT: The ecliptic is the imaginary line tracing the route that The Sun, the Moon, and the Planets take across the sky, over the year.
Perseus can be spotted in the Northern Hemisphere, also referred to as the Northern sky. It includes a dense portion of the Milky Way and contains several star clusters and the variable star ‘Algol’.
This is the direction from which the Perseid Meteor showers originate.
The Perseus Constellation is a well-known guide-point in the sky used by astronomers and amateur stargazers to identify certain Deep Sky objects; like the neighboring Andromeda Galaxy.
When to see The Perseid Meteor Showers
The peak month for the Perseid meteor showers associated with Constellation Perseus is August. They are awarded the crown of the best meteor shower of the year, as they are very speedy in action and incredibly bright.
What’s within the Perseus Constellation?
- 2 associated meteor showers known as the ‘Perseid Meteor Showers – ‘The Perseids’ and ‘The September Perseids’.
These Meteor showers are formed by space rocks, (meteoroids), raining towards Earth.
There are 8 well-known major meteor showers, listed from the beginning of the year, as follows:
- January – ‘The Quadrantids’, associated with the old astronomically obsolete Constellation of Quadrans Muralis. It is now often forgotten as a Constellation. Its asteroid/rock comet of origin is 2003EH1
- April – ‘The Lyrids’, associated with the Constellation of Lyra. One of the oldest known meteor showers, being observed for over 2,700 years. Comet of origin is C/1861 G1 Thatcher
- May – ‘The Eta Aquarids’, associated with the Constellation of Aquarius. Known for speed. Its comet of origin is 1P Halley
- July – ‘The Delta Aquarlids’, associated with the Constellation of Aquarius. It is faint and difficult to spot unless especially if there is a full moons it creates bright light which distorts the clarity of the meteor shower. Comet of origin is not known but 96P Machholz is suspected
- August – ‘The Perseids’, associated with the Constellation of Perseus. This is considered to be the best meteor shower of the year. Its Comet of origin is 109P/Swift-Tuttle is sometimes simply referred to as the Comet Swift-Tuttle
- October – ‘The Orionids’, associated with the Constellation of Orion. This is considered to be one of the most beautiful meteor showers in the year. Its comet of origin is 1P/Halley
- November – ‘The Leonids’, associated with the Constellation of Leo. The rates of showers are low compared to other meteor showers. Its comet of origin is 55P/Tempel-Tuttle
- December – ‘The Geminids’, associated with the Constellation of Gemini. Considered to be one of the best and most reliable annual showers. Its origin is uncertain, could be a rock comet, asteroid or 3200 Phaethon
Astronomers and Comets
We have the American astronomer, Lewis Swift to thank for the discovery of 13 comets and 1,248 nebulae that were previously catalogued, and more are being identified all the time. The Comets he discovered all bear his name.
Two other American astronomers, brothers Horace Tuttle and Charles Tuttle, discovered the Comet Temple-Tuttle. This Comet was actually independently identified twice, once in 1865 by the Tuttle brothers and again in 1866 by Ernst Temple. Hence the name awarded to recognise both was the Comet Temple-Tuttle.
Within the Constellation Perseus
The Constellation of Perseus is formed by of a number of different components. The different components housed by the Constellation Perseus are mainly Stars, Deep sky objects and Messier objects (galaxies)
Images of many of the largest objects and smallest debris in Space have been captured using professional Space telescopes, such as the NASA Spitzer Space Telescope, operated by NASA, and the famous Hubble Space Telescope
Nothing stands still in the sky. Planets are continually being discovered and lists updated. The Constellations change their positions throughout the year as the Earth rotates around the Sun.
This means our position in space is forever changing and as a result our view of what’s in space changes too, and will continue to do so.
From children to the elderly, we have had an ongoing fascination, with our solar system and star system. Perhaps it’s because the enormity and variety within it makes us realize just how large and exciting the universe is.
The Perseus celestial pole
The celestial pole defines the poles of the celestial equatorial coordinate system.
An object at the Celestial pole has a declination of 0 degrees.
- The declinations for the north celestial pole is +90 degrees
- The declinations for the south celestial pole is -90 degrees
The celestial poles are not permanently in a fixed position against the background of the stars as everything moves in Space.
Perseus is located in the northern celestial sky at a +40 degree north declination and a 4 hours right ascension.
Historical significance: the legends, and myths surrounding Constellation of Perseus
When it comes to the many recognized constellations in the sky, Perseus is one of the largest Constellations.
However the origins of the earliest Constellations probably date back to prehistory.
Many ancient civilizations have related the Constellations in the sky to suit their beliefs and creations itself. They have been the subject of folklore and experiences for a very long time.
There are many Greek myths and legends surrounding the origin and names of the constellations.
Acrisius, the King of Argos, and father of Danae, was told by the oracle of Apollo that one day he would be killed by his Grandson. He therefore imprisoned his daughter,Danae in a bronze underground chamber so she could not meet anyone to have children with. Zeus however discovered her underground and they had a child named Perseus.
Acrisius was so angry when he discovered the baby that he locked Danae and baby Perseus in a crate and threw them into the sea. The crate floated to the Island of Seriphos that was ruled by King Polydectes. They were washed ashore and rescued by Dictys, the brother of King Polydectes.
King Polydectes fell in love with Danae the moment he saw her, but she rejected him. He decided Perseus was the obstacle, so he needed to get rid of her son, so he brought Perseus a wife and asked for a horse as a bride gift. Perseus was poor so he asked to bring a different gift. So King Polydectes set him a dangerous task and asked him to bring him the head of the gorgon Medusa, assuming she would turn him into stone with one look, and then her would be free to marry his mother Danae.
Perseus accepted the challenge and cut off the head of Medusa and then used her head as a weapon. He turned Polydectes into stone for harassing his mother and accidently killed his grandfather, Acrisius, as per the prophecy.
The Constellation Perseus is identified as the outline of the body of Perseus, the Hero.
The other myth of how Perseus rescued Andromeda
The myth begins with Cassiopeia, the wife of King Cepheus, of Ethiopia, who was a vain queen. Together they had a daughter Andromeda. Cassiopeia boasted that she was more beautiful than all of the 50 Nereids (the Sea Nymphs). The angry Sea Nymphs asked Poseidon, the god of the sea, who was married to a Sea Nymph(Amphitrite), to punish Cassiopeia. He obliged and sent the Sea Monster Cetus to ravage the kingdom.
To appease the Sea Monster, Cassiopeia tied her daughter Andromedato a rock for him to eat. The hero Perseus, on his winged horse Pegasus rescued Andromeda just in time, from being devoured by Cetus. They married and lived happily ever after. The gods were so happy at the outcome that they placed them in the heaven as stars. However, to show their displeasure with Cassiopeia she was tied to a chair and put in the heavenswhere she revolves around the celestial pole, sometimes in an upside down position.
The Babylonians also recorded details of various bright stars and objects within the constellations in their Babylonian star catalogues before 100BCE.
The Perseid meteor showers – When Do They Occur?
There are 2 annual Perseid meteor showers associated with the Constellation of Perseus; they are known as
- The ‘Perseids’
- The ‘September Perseids’
The Perseids are one of the brightest meteor showers and are associated with its parent body the comet ‘Swift-Tuttle’. Visually, the location of this number of meteors appears to come from within the constellation of Perseus.
The name comes from the Greek word Perseidai meaning the ‘sons of Perseus’
The Perseid meteor showers, containing many bright meteors, occurs between July 23 and August 20 each year.
Peak time for the shower is around August 9-13 every year and they are visible by naked eye in the Northern Hemisphere.
This particularly bright meteors shower is associated with the constellation of Perseus because the point at which they appear is located in that direction.
The Belief in Saint Lawrence
In the Catholic religion the Perseids are referred to as the ‘Tears of Saint Lawrence’.
The religious belief is that he returns to earth every year on August 10, as a shooting star, or fireball (on the date of the Saint’s martyrdom).
It is believed that when the embers from this fireball meteor shower’s peak cool down they appear under plants as earth.
Fun Facts about Meteor Showers– Did you know that?
- The Comet known as Swift-Tuttleis forecast to experience a cosmic near miss collision with Earth in the year 3044. A near miss is considered to be around 1 million miles apart.
- A Perseid Meteor is heated to a temperature of a temperature of around 3,000 degrees Fahrenheit (1,650 Celsius) as it enters the Earth’s atmosphere. At this heat the Meteor vaporizes and forms a shooting star. The larger ones can explode in a brighter flash known as a Fireball, which can sometime be heard from Earth.
- The height of the average shooting star we can see by naked eye is located about 60 miles high.
- Not all Comets visit the inner Solar System.
- The Perseid Meteroids can be between 60 to 100 miles apart in distance as the fall (before they enter the Earth’s atmosphere).
- The next time the Swift-Tuttle is due to return to Earth is 2126, but there is no need to worry as it will not crash into Earth.
- The Comet Swift-Tuttle takes 130 years to orbit the Sun and each time it leaves a trail of Space Debris. This Space Debris continues to drift through Space, roughly in the same direction of the Comet it fell off.
- Constellations like Perseus are not part of our Solar System; they are groups of stars that appear to form shapes that are visible with the naked eye from Earth.
- The Sun does not belong to any constellation.
- A Constellation does not actually exist as a fixed object, it is a group of bright stars that happen to be in a random place and are light years apart and ever moving. We see the pattern of their presence.
Perseid Meteor Showers: Commonly Asked Questions
Q. Why are Meteor Showers, like The Perseids, best seen in pre-dawn hours?
A. When the Earth rotates it is the side facing the Sun at any given time that attracts more Space Debris. As this area of the sky is directly overhead at dawn, it is recommended to view the Perseids before this time or they may be occluded by debris. The same principle applies when viewing random Shooting Stars.
Q. What’s the difference between a Constellation and an asterism
A. The stars that make up a Constellation have a definite position and form, whereas an asterism is a collection of stars without a fixed position.
Q. What prevents us seeing the different meteor showers, meteor streaks, shooting stars and fireballs that usually light up the night sky?
A. Light pollution, fog, city lights and artificial lights all limit our visibility of even the largest objects in the sky at night, or in the pre-dawn hours.
Q. What is the connection between ESO (the Elder Scrolls Online) and Meteor showers?
A. This is connected with a virtual video game for PlayStation and not connected with actual space.com. The ESO: Meteor shower can be seen in the night sky over Tamriel in the Elder Scrolls Online Game
Q. Will the Constellations change over time?
A. The Constellations is continually on the move.
The images we form in our imagination to make objects, shapes and patterns out of the constellations have already shifted over time.
As we view the night skies from Earth they are likely to continue to shift and possibly in time the images may look very different.
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