One of these amazing Celestial events involving meteors, meteoroids or meteorites is the celestial event known as ‘The Meteor Shower’. 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 Orion. We are of course talking about the Orionid meteor shower.
The Orionid Meteor Shower (The Orionids)
The different names
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 space object depending on where it is on its journey from Space to Earth
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 on their closest approach, if they make contact with Earth, they become meteorites:
– Is a small fragment of space rock, or iron, from outer Space (that is either a meteoroid or asteroid, or extinct Comet), 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 night sky as they travel rapidly are what’s known as ‘Shooting Stars’ or ‘Fireballs’.
FACT: Shooting Stars are not Stars they are in fact space debris left behind from the parent body, Comet or Asteroid.
The part of the Shooting Star known as the bright meteor streak or the flaming tail is one of the top sights for Skywatchers.
It is a common image associated with a Shooting Star, although it 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, in the dark skies, were powerful, and messages of doom, or warnings from their deities (gods).
In the ancient Greek and Roman religions these cultures believed in Helios (Latin name Helius), as the god and personification of the Sun. Any activity involving Helios was feared and respected. It has been depicted over the years in imagery as a horse-drawn chariot racing through the sky.
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, or Rock 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.
FACT: A Rock Comet is actually an asteroid that travels very close to the Sun and as it does so the solar heating it experiences scorches dusty debris off its rocky surface. Rock Comets can even grow tails from the rocky debris.
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, like the Orionids 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 Orionids Meteor Shower– Facts in brief:
What is it? –
The Orionid Meteor showers are named after the Constellation Orion, and appear to radiate from a point close to its Brightest Star Betelgeuse (in the image this point is the tip of the club, or weapon, that the Hunter is holding high in the air).
Visible from both the Northern Hemisphere and the Southern Hemisphere, this meteor shower peaks in late October. Meteor showers originate from a large space object, such as a Comet, or an asteroid or even an extinct Comet.
The name suggests they fall like a shower of rain but this is not the case. They fall intermittently and on average it may only be possible to see between 10-20 per hour in the Orionids. In the case of both the Orionids Meteor Shower and the Eta Aquarids Meteor Shower their parent body is the famous Comet called Halley’s Comet (1P/halley).
The meteor showers in the proximity of the Constellation of Orion occur as annual meteor shower events and are therefore referred to as the ‘Annual Orionids Meteor Showers’, or ‘The Orionids’ for short.
It is possible for sky watchers of the earthsky to see what is considered to be the most beautiful meteor shower of all of the annual meteor showers, when viewed on a dark night in late October.
The Orionids meteor shower peaks annually in mid-October.
City lights causing light pollution can negatively impact the visibility of meteor showers and the brightness of a full moon, or even a new moon, can also affect the visibility, throughout the night until early morning.
What’s special about The Orionid Meteor Shower?
There are many factors that distinguish The Orionids from the other named annual meteor showers.
First find the Constellation of Gemini, and the Constellation of Orion, that’s the best direction in which to see The Orionids, one of the major meteor showers. (Just north of the bright star Betelgeuse in Orion)
Orion is located on the celestial equator but far south of the ecliptic.
This meteor shower is visible from both the Northern Hemisphere and the Southern Hemisphere. When viewed from mid-northern latitudes the point of origin (the radiant) appears to come from a southeastern sky.
The Orionids Meteor Shower is one of the more spectacular sights in the night sky, resembling falling stars as the travel through the Earth’s upper atmosphere.
They originate from a radiant point and they streak in different directions.
FACT: The Earth’s upper atmosphere is a layer of gases held in place by Earth’s gravity. It is a combination of ionized gas, ions and electrons that exist permanently in the atmosphere located around 70km above sea level.
Origin Of The Orionid Meteor Shower
The connection between Shooting Stars and Comets was first made in the 1800s.
The Orionids originate from the famous Comet called ‘Halley’s Comet’, the parent body officially known as 1P/Halley, named after the astronomer Edmund Halley who made the connection.
Halley’s Comet causes much excitement when it passes through the inner Solar System.
They’re considered one of the most abundant showers
- The Orionids are considered to be the most prolific meteor showers in the night sky.
Orionids are best seen in the early morning, just before dawn, in late October.
They’re Bright and Beautiful
- The Orionid meteoroids are bright and considered to be one of the most beautiful, sights in a dark night sky.
They are not just visible in the direction of Orion and Gemini as they can actually be viewed throughout the night sky in October, only dimmed by the brightness of a full moon.
They’re Reliable and Fast
- The Orionid Meteor Showers are considered reliable. It has been reported that its meteor shower peak occurs at an average of 50-70 meteors per hour, travelling at a meteor velocity of 41 miles per second (66 kilometers).
They are considered to be one of the major meteor showers with an average peak of 15 meteors per hour, seen is a dark sky.
The Orionids can be seen from many parts of the winter sky, but are only become visible when they are about 30 degrees from their radiant point.
The Orionids is considered to be a spectacular meteor shower, which exhibits amazing explosions of light and color known as Fireballs.
The Fireballs emitted from The Orionids are sometimes viewed as being colorful as they enter the Earth’s. They are especially spectacular during a waxing crescent Moon as you can see the tails and shapes they leave behind as they travel.
This is a treat for any level of sky watcher. In October it is also possible to see other meteor showers such as The Taurids and The Epsilon Geminids.
Where do they come from?
Most meteoroids are formed from the bits of space debris that possibly burn off a Comet as it orbits the Sun and expand along the orbit of the comet forming a meteoroid stream. If the Earth passes through this stream it will encounter a meteor shower.
The parent body of the Orionids is Halley’s Comet, and they appear to radiate from the location of the Constellation of Orion.
It is estimated to take around 76 light years to orbit the Sun.
The Orionids association with the Constellation Orion
The Orion Constellation is named after the Hunter known as Orion from Greek Mythology. The Orion Constellation is one of the oldest known constellations, and ranks as the 26th largest Constellation as one of the original 48 Constellations listed by Greek Astronomer Ptolemy, in the 2nd century.
Orion is one of the official International Astronomical Union (IAU) listed 88 modern constellations as seen in the night sky from Earth.
Orion (its Latin name) is quite easy to recognize, as it resembles the outline of a Hunter holding a large shield in one hand and a raised weapon in the other.
Where is the Orion Constellation located? –
Constellation Orion is positioned in the first quadrant of the Northern Hemisphere. 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.
Where can Orion be seen?
Co-ordinates of a right ascension, or left ascension and their declination are used to locate all of the Constellations, like Orion.
Orion is one of the most prominent and recognizable Constellations and can be viewed throughout the world. Orion’s Belt is a well-known landmark in the night sky, associated with this Constellation.
The Constellation of Orion lies at 5-hour right ascension and the Declination is + 5 degrees.
It’s visible in the Southwestern sky from the Northern Hemisphere, and in a Northwestern sky from a Southern Hemisphere viewpoint.
How can you identify the location of any Constellation?
The simplest method for spotting the location of any particular Constellation from Earth is to first of all locate the brightest star in that Constellation, and then look at the neighboring illuminations, to see if you can identify a recognizable pattern.
Orion, and its associated contents, can be spotted in the Northern Hemisphere, also referred to as the Northern sky. This is the direction from which the Orionids Meteor showers originate.
The Orion Constellation is a well-known guide-point in the sky used by astronomers and amateur stargazers, light pollution permitting. One favourite spot for sky-watchers is the famous asterism ‘Orion’s Belt’.
When to see The Orionid Meteor Shower
The peak month for The Orionid meteor showers associated with Constellation Orion is October. They are one of the more attractive, fast and colorful meteor showers of the year, as they are active in action and bright.
When the Moon is in its waxing crescent phase and setting before midnight, the sky will be dark and therefore the best conditions for viewing the Orionids.
What’s within the Constellation of Orion?
The Orion Constellation is associated with the annual meteor showers known as the ‘ Orionids Meteor Showers – ‘The Orionids’, as the bright meteors appear to radiate from Orion.
These Meteor showers are formed by space rocks, (meteoroids), racing quickly towards Earth.
When any number of meteors enter the Earth’s atmosphere at high speed they catch fire, through friction and look like fireballs or what we know as Shooting Stars (Meteors). If it survives the trip and it finally hits Earth it is then known as a meteorite.
Meteor showers are events linked to the nearest Constellation and the particular month of the year in which they peak. There are 8 well-known major meteor showers that take place every year.
They range from appearing quite faint Shooting Stars to more vibrant meteor storms, with colorful streaks and the occasional Fireballs. The Orionids is often regarded as one of the most beautiful annual meteor showers.
Within the Constellation Orion
The Constellation of Orion is formed by of a number of different components.
The different components housed by the Constellation Orion 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, from spotting Saturn to identifying the Polar Star, and seeing Full Moons and New Moons. Perhaps it’s because the enormity and variety within it makes us realize just how large and exciting the universe is.
The Orion 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.
Orion is located in the northern celestial sky at a +5 degree north declination and a 5 hours right ascension.
Historical significance: the legends, and myths surrounding Constellation of Orion
Myths Around Orion & The Orionid Meteor Shower
When it comes to the many recognized constellations in the sky, Orion is one of the larger Constellations, ranking 26th overall and occupying around 1.4% of the sky.
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 even depictions of this strong and bold Hunter in prehistoric cave carvings, in Europe, estimated to date back as far as 38,000 years.
There are many Greek myths and legends surrounding the origin and names of the constellations.
The Constellation of Orion is represented as ‘the bold and very strong Hunter’, born from a Gorgon mother and Poseidon (Neptune) as his father.
The Babylonians also recorded details of various bright stars within the Constellations in their Babylonian star catalogues before 100BCE. They referred to it as ‘Mul Sipa. Zi. An.Na’. This translates as ‘The True Shepherd of Anu’, (the god of Heaven), or ‘The Heavenly Shepherd’.
It is sometimes also represented as a walking Bird.
The Egyptians believed that Orion was actually the god ‘Sah’
Christian and Hebrew teachings
There are also references to Orion in the Christian ‘Bible, and it may have a Hebrew root, referring to hope, as in hope for winter rain.
The Orionid meteor shower
The Orionids meteor showers, containing many bright meteors, are active between October 2 and November 7, each year.
The showers peak, October 21, around 02.00, local time every year, as this is the point at which they are highest in the sky. They are visible by naked eye in the Northern Hemisphere and Southern Hemisphere.
This particularly bright meteors shower is associated with the Constellation of Orion because the point at which they appear is located in that direction.
The Orionids are one of the brighter and prolific meteor showers and are associated with when Earth passes through the stream of debris from its assumed parent body, Halley’s Comet. The location of this number of meteors appears to come from within the Constellation of Orion.
The Orion name association in different cultures
Over time different cultures have looked at the night sky and made images from the random bright objects they viewed. Many myths, beliefs, stories and fears followed those sightings.
Greek and Roman Mythology – Orion meaning ‘Warrier’ or the ‘Hunter’, (the Son of Poseidon – Greek, Son of Neptune Roman belief)
Ancient Egyptians – associated Orion with their god of the afterlife ‘Osirus’
Aboriginal People in Australia, and many South American cultures –see Orion as a large flightless bird “Rhea”
Middle Irish – associated Orion and the female Orianna name with the ‘Golden dawn’
Old English language – associated Orion with ‘a Fool’
Fun Facts – Did you know that?
- Earth passes through many debris streams in a year.
- The most active citing of Halley’s Comet was in 2009, in the early morning of October 21. It wasestimated to have travelled at a speed of 140,000 mile per hour (230,000km/hour)
- In 2020, the Orionid Meteor Shower peaked early on Wednesday morning in October 21.
- The Orionids create prolonged explosions of light
- They are the most colorful meteor shower, with reported sighting describing having seen yellow, red, blues or even green as well as the usual white
- Halley’s Comet was last viewed from Earth in 1986 and is not due to be visible again in the inner solar system until 2061
- The gravity of the Planet Jupiter is responsible for pulling the particles in the Meteor showers closer to Earth over time
- A Meteor is heated to 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.
- An extinct Comet is one which has lost its ice by coming too close to the Sun
- Constellations like Orion 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.
Commonly Asked Questions
Q. Why are Meteor Showers, like The Orionids, 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 Orionids 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.
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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