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 of Gemini (near Castor). Lets take a look at the Geminid meteor showers.
The Geminid Meteor Showers
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 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 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 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.
There is a belief that when the asteroid Phaeton was much younger it got caught up the orbit of Saturn and leaves a trail of debris behind as it passes Earth each year.
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 Geminid 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 Geminid Meteor Showers– Facts in brief:
What is it? –
The Gemini Meteor showers are named after the Constellation of Gemini, which is the closest Constellation to where they appear to be coming from.
The meteor showers originate from a large space object, possibly an asteroid or extinct Comet, known as 3200 Phaethon. This Parent Body is called the asteroid 3200 Phaethon, as it is believed to be a Palladian asteroid although it takes a rock comet orbit.
The meteor showers in the proximity of the Constellation of Gemini (near Castor) occur as annual meteor shower events and are therefore referred to as the ‘Annual Geminid Meteor Showers’, or ‘The Geminids’ for short.
It is possible for sky watchers to see what is considered to be the best meteor shower of all of the annual meteor showers, when viewed in a dark night of December. The Geminid meteor shower peaks mid-December.
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.
What’s special about The Geminids?
There are lots of factors that distinguish The Geminids from the other named annual meteor showers.
Find the Constellation of Gemini, and the Constellation of Orion, that’s the best direction in which to see The Geminids, one of the major meteor showers.
This major meteor shower is visible from both the Northern Hemisphere and the Southern Hemisphere.
Earth passes through many debris streams in a year and the Geminids Meteor Shower is the most massive.
Origin Of The Geminid Meteor Showers
The Geminids and The Quadrantids are the only two meteor showers that do not originate from a Comet.
The Geminids were one of the later meteor showers to be identified, around 1862. This compares with other well-known meteor showers like The Leonids, identified as far back as 902 AD, and The Perseids identified around 36 AD.
They’re considered one of the Best
- The Geminids and The Perseids are considered the 2 best meteor showers in the night sky. Geminids are best seen from 02.00 to 03.00, mid December, and The Perseids are best seen from midnight until the middle of the night local time.
- The Geminid meteoroids are bright and vibrant, displaying an apparent magnitude range of -5 to +1. They are not just visible in the direction of Gemini as they can actually be viewed throughout the night sky any night of December, only dimmed by the brightness of a full moon.
- The Geminid Meteor Showers are considered highly reliable compared with other meteor showers. However they are increasing in intensity every year and are now much more active with an average of 120-160 meteors seen per hour. They are considered to be one of the major meteor showers and reliable.
They can be seen from most parts of a winter skies and give off a yellow hue. This is indeed a treat for any level of sky watcher.
The Geminids is considered one of the most spectacular meteor showers, which exhibits amazing explosions of light and color known as Fireballs.
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 Geminids and The Quadrantids are different from the other meteor showers as their point of origin is not a comet but an asteroid. The parent body of the Geminids is the Geminid asteroid 3200 Phaethon, and they appear to radiate from the location of the Constellation of Gemini.
The 3200 Phaethon asteroid is an unusual rocky object that orbits closer to the Sun than any other asteroid. It is estimated to take around 1.4 light years to orbit the Sun.
The Geminids association with the Constellation Gemini
It is the Zodiacal Constellation of Gemini that gives the Geminid meteor showers their name. The Gemini Constellation is named after the twins, Castor and Pollux who were known characters from both Greek and Roman mythology.
The Gemini Constellation is one of the oldest known constellations, and ranks as the 30th largest Constellation as one of the original 48 Constellations listed by Greek Astronomer Ptolemy, in the 2nd century.
Gemini is one of the official International Astronomical Union (IAU) listed 88 modern constellations as seen in the night sky from Earth.
Gemini (its Latin name) is quite easy to recognize, as it clearly resembles the outline of the twins, which look like 2 stick people with the two brightest stars representing their heads
Where is the Gemini Constellation located? –
Constellation Gemini is positioned in the second quadrant of the Northern Hemisphere, north of the ecliptic. It is sometimes referred to as being located in the NQ2 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 Gemini be seen?
Co-ordinates of a right ascension, or left ascension and their declination are used to locate all of the Constellations, like Gemini.
Gemini is most prominent in the Northern Hemisphere, in wintertime in December.
The Constellation of Gemini lies at 7-hour right ascension and the Declination is + 22 degrees North.
It’s visible in the Northern Hemisphere at latitudes between +90 degrees and -60 degrees and covers an area of 514 square degrees in the Northern sky.
The Geminids are one of the few meteor showers that are visible from both the Northern Hemisphere and the Southern Hemisphere. They also can be found lower in the Earth’s atmosphere than many of the other meteor storms and produce long attractive arcs.
Meet the neighbors
The Constellation of Gemini is bordered by several other Constellations:
- Lynx and Auriga – to the North
- Canis Minor, Monoceros and Orion – to the South
- Taurus – to the East
- Cancer – to the West
Accounting for the distances of all the main star and objects within the Constellation of Gemini, the average distance from Earth is 887 light-years.
This is also the approximate distance of the closest approach to Gemini.
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.
Gemini, 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 Geminid Meteor showers originate. The Gemini Constellation is a well-known guide-point in the sky used by astronomers and amateur stargazers, light pollution permitting.
When to see The Geminid Meteor Showers
The peak month for The Geminid meteor showers associated with Constellation Gemini is December. They are one of the more spectacular meteor showers of the year, as they are active in action and incredibly bright.
What’s within the Gemini Constellation?
The Gemini Constellation contains:
- 2 associated meteor showers known as the ‘ Meteor Showers – ‘The Geminids’ and ‘The Rho Geminids’.
These Meteor showers are formed by space rocks, (meteoroids), raining 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, listed from the beginning of the year, as follows:
- January – ‘The Quadrantids’, associated with the old astronomically obsolete Constellation of Quadrans Muralis. It is often forgotten as a Constellation. Its asteroid/rock comet of origin is 2003EH1
- April – ‘The Lyrids’, associated with the Constellation of Lyra, is one of the oldest known meteor showers, being observed for over 2,700 years, and recorded in ancient Chinese texts. Comet of origin is C/1861 G1 Thatcher
- May – ‘The Eta Aquarids’, (or Eta Aquariid), associated with the Constellation of Aquarius. Known for speed. Its comet of origin is 1P Halley
- July – ‘The Delta Aquariids’, associated with the Constellation of Aquarius. It is faint and difficult to spot unless there is a full moon. 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, like the Eta Aquarids.
- 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, or the asteroid 3200 Phaethon.
They range from appearing quite faint Shooting Stars to more vibrant meteor storms, with colorful streaks and the occasional Fireballs.
Within the Constellation Gemini
The Constellation of Gemini is formed by of a number of different components.
The different components housed by the Constellation Gemini 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 Gemini 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.
Gemini is located in the northern celestial sky at a +22 degree north declination and a 7 hours right ascension.
Historical significance: the legends, and myths surrounding Constellation of Gemini
When it comes to the many recognized constellations in the sky, Gemini is one of the larger Constellations and one of the 12 Constellations of the Zodiac.
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.
The Constellation of Gemini is represented as ‘the celestial twins’
Leda was the mother of the twins, Castor and Pollux, but they had different fathers. Leda’s husband Tyndareus, the King of Sparta, was the mortal father of Castor, whereas Pollux was the divine son of Zeus.
Zeus disguised himself as a Swan (Cygnus) to seduce Leda and the twins were later born from an egg. They are sometimes depicted as wearing a part of the eggshell as a helmet on their heads.
The myth describes their involvement in a violent cattle theft dispute with their cousins and as a result Castor was killed. Zeus offered Pollux immortality, but he told him he wanted to share it with Castor.
As a result they were believed to live as gods on alternate days on Olympus, and according to this myth the bright Stars in Constellation Gemini, Pollux and Castor, are not found above the horizon at the same time.
The Babylonians also recorded details of various bright stars within the constellations in their Babylonian star catalogues before 100BCE.
The Geminid meteor showers
There are 2 annual Geminid meteor showers associated with the Constellation of Gemini; they are known as:
- The ‘Geminids’The ‘Rho Geminids’
- The Geminid meteor showers, containing many bright meteors, occurs between December 4 and December 17 each year.
The showers peak, December 14, 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 Gemini because the point at which they appear is located in that direction.
The Geminids are one of the brighter meteor showers and are associated with its assumed parent body, the asteroid 3200 Phaethon. The location of this number of meteors appears to come from within the Constellation of Gemini.
The names from the different cultures
Greek – The name ‘Dioscuri ‘is also used in connection with the heavenly Twins. This word comes from Greek, ‘Dios’ means god, and ‘Kouri’ meaning sons, together they are known as ‘the sons of god’.
They are known as Castor and Pollux, which is also the names of the two brightest Stars in Gemini.
Latin – Gemini means the twins, meaning Pollux and Castor
Indo-European – Gemini, comes from the root ‘Yem’ meaning – to pair
French – Gemeau means twins
Middle Irish – Emon (male)or Emuin (female)
Old Indian – Yamah/Yama (male) or Yami (female), considered to be the Hindu Adam and Eve (who were twins)
Fun Facts – Did you know that?
- The Geminids reach a deeper depth and burn lower into the Earth’s atmosphere than most other meteor storms
- 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
- The Geminids were first observed in 1833, from the Mississippi, in the USA.
- The gravity of Jupiter is responsible for pulling the particles in the Meteor showers closer to Earth over time
- A 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 3200 Phaeton asteroid, space rock is only around 5.8km in diameter
- The height of the average shooting star we can see by naked eye is located about 60 miles high. The Geminid meteors typically disintegrate about 24 miles (38 Km) from the surface of the Earth
- An extinct Comet is one which has lost its ice by coming too close to the Sun
- In 2017, the asteroid 3200 Phaethon, a possible rock Comet, came within 6.4 million miles of Earth (10.2 million km or 26 lunar distances), which believe it or not is quite close for an asteroid.
- The asteroid 3200 Phaeton orbits the Sun every 1.4 years and each time it leaves a trail of Space Debris. At times it passes very close to the Sun, some 0.15 astronomical units distant, and within the orbit of Mercury.
- Constellations like Gemini 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 name of one of the two main Stars representing the outline in Gemini, Castor, means ‘Beaver’ in both Latin and Greek
Commonly Asked Questions
Q. Why are Meteor Showers, like The Geminids, 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 Geminids 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 largestobjects 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.