Meteor Section        

 
 
The 2013 Eta Aquarid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, ‘Composite of approximately 50 images containing 26 meteors, meteor train, 17 % moon, zodiacal light and Pilbara desert.
The 2013 Eta Aquarid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, ‘Composite of approximately 50 images containing 26 meteors, meteor train, 17 % moon, zodiacal light and Pilbara desert.

© Colin Legg, 2013, Australia

The eta Aquariids (ETA) are active between April 17 and May 24. The strongest activity is usually seen near May 7, when rates can reach 25-30 meteors per hour as seen from the tropical areas of the Earth. Unlike most major annual meteor showers, there is no sharp peak for this shower, but rather a plateau of good rates that last approximately one week centered on May 7. The eta Aquariids are particles from Halley’s Comet, which last passed through the inner solar system in 1986. The meteors we currently see as members of the eta Aquariid shower separated from Halley’s Comet hundreds of years ago. The current orbit of Halley’s Comet does not pass close enough to the Earth to be a source of meteoric activity.

The eta Aquariids are only visible during the last couple of hours before the start of morning twilight. The reason for this is that the radiant (the area of the sky where these meteors appear to shoot from) is situated approximately 60 degrees west of the sun. Therefore it rises before the sun in the morning hours. The time of radiant rise is between 2:00 and 3:00 local daylight saving time (DST), depending on your longitude. The real key is the latitude. There is an observing window for this shower between the time the radiant rises and the beginning of morning nautical twilight. This window ranges from zero at 60 degrees north latitude to all night in Antarctica. Unfortunately in Antarctica, the radiant never rises very high in the sky and most of the activity is not visible from there. The best combination of a large observing window and a decent radiant altitude occurs between the equator and 30 degrees south latitude. From this area the radiant reaches a maximum altitude of 50 degrees at nautical twilight. The observing window ranges from 3.5 hours at the equator to slightly over 4.0 hours at 30 degrees south latitude. Going further south will increase your observing window but the maximum altitude will begin to fall closer to the horizon.

Since most meteor observers live in the northern hemisphere, here are the conditions at several different latitudes: the observing window for 50N is 1.5 hours with a radiant altitude of 15 degrees. The observing window for 40N is 2.25 hours with a radiant altitude of 25 degrees. The observing window for 30N is 2.75 hours with a radiant altitude of 35 degrees.

Aquarius constellation
Aquarius constellation – “Peace sign”

Near maximum, the radiant may be easily spotted as it lies near the “water jar” in Aquarius. This “Y” shaped pattern of stars is also known as the “peace sign” to some observers. It should be noted that very few meteors are actually seen at the radiant. This position just happens to be the apparent source of the activity. More activity is seen further up in the sky where longer shower members can be seen. That is why it is advised to look half-way up in the sky. Do not look straight up as this is the direction of least meteoric activity. By looking at the zenith you are looking though the thinnest slice of atmosphere possible. This is great for lunar and planetary viewing but not for meteor observing. Have the horizon be at the bottom of your field of view and your center will lie near the optimal forty-five degree altitude zone.

The conditions for viewing the eta Aquariids in 2019 are close to perfect. A new moon will occur on May 4, only a few days before maximum activity. The moon will not start to interfere with viewing these meteors until May 13, when it sets shortly after the radiant rises in the opposite side of the sky.

To best see these meteors you should start viewing near the time the radiant rises. This is between 2:00 and 3:00am for most observers situated at mid-northern latitudes. It would be best to view toward the eastern half of the sky with the radiant in the lower portion of your field of view. This way you can see these meteors shooting in all directions out of the radiant, even downwards. This suggestion is good for all observers no matter your location. These meteors will shoot in all directions, especially low in the northeast and southeastern sky. The best ones will shoot straight upwards through the center of your field of view. The eta Aquariids are swift meteors leaving a high percentage of persistent trains. Unlike the Geminids and Perseids, fireballs from this source are rare.

The graphs below show eta Aquariid and sporadic activity from 2007-2017. Each dot represents a single hourly rate reported by a single observer, corrected for effective time, obstructions, sky conditions, and zenith angle. Reported sporadic rates are also plotted for reference (also corrected for effective time, obstructions, and sky conditions). Each plot is in terms of Solar Longitude, not date, allowing direct comparison between years. The expected maximum for the eta Aquariids each year lies at solar longitude 46.2 Due to the usually low zenith angle of this shower, there is a large amount of data scatter and a broad, ill-defined peak even in a good year without lunar interference.

The graphs are courtesy of James Richardson using data from the International Meteor Organization (IMO). It should be noted that the corrected rate values do not represent rates that anyone will actually see, but are simply a way of combining raw meteor hourly rates from multiple observers in various locations and observing under disparate conditions. The corrected raw data does a good job of showing the ramp up and ramp down of each shower as they occur/occurred, where the actual ZHR will be roughly in the *middle* of the plotted numbers (that is, don’t follow the top of the plot, watch the middle of the plot). Also note that the vertical scale is logarithmic, such that a typical shower will generally ramp up and down in ‘saw tooth’ fashion, forming a triangular peak (sometimes with asymmetrical sides).

Meteor shower rates, as seen by an individual observer, are quite random (following a Poisson distribution), more random than most people intuitively expect, such that wide variations from one hour to the next can occur, or wide variations between two observers at two different locations in the same hour. The plots also point to the importance of observer accuracy in reporting their observations: times, counts, limiting magnitude, sky obscuration, shower member identification. I think it is elucidating for observers to see their raw and minimally corrected (normalized) rates directly, rather than as a averaged, single value with error bars.

 

 
 

The Quadrantids can be one of the strongest displays of the year, yet they are difficult to observe. The main factor is that the display of strong activity only has a duration of about 6 hours. The reason the peak is so short is due to the shower’s thin stream of particles and the fact that the Earth crosses the stream at a perpendicular angle. Unlike most meteor showers which originate from comets, the Quadrantids originate from an asteroid: asteroid 2003 EH1. Asteroid 2003 EH1 takes 5.52 years to orbit the sun once. It is possible that 2003 EH is a “dead comet” or a new kind of object being discussed by astronomers sometimes called a “rock comet.”

The name “Quadrantids” comes from Quadrans Muralis, a former constellation created in 1795 by the French astronomer Jérôme Lalande that is now part of Boötes.

In order to see the Quadrantids at their best they need to reach maximum near 04:00 local standard time so that the radiant lies high in your sky. The early January weather is also a major factor as cloudiness is usually prevalent this time of year. If it is clear then it can also be bitterly cold, making observations uncomfortable at best. In my many years of observing, I have only managed to catch the Quadrantids at maximum once. Despite the strong wind that morning, it was a sight I will never forget as the last two hours before dawn produced in excess of 100 Quadrantids each.

The Earth encounters Quadrantid meteors from December 22 through January 17. Rates are extremely low away from the January 4 maximum. For 2019, the maximum is expected to occur near 02:30 Universal Time (UT) on January 4. This timing favors Europe, Northern Africa, and extreme western Asia. Observers situated in other parts of the world can expect around 25 Quadrantids per hour at best. The moon will not be a factor on January 4th as it is lost in dawn’s glare, too close to the sun to be seen.

The Quadrantid radiant is located in northern Bootes and is best placed highest in a dark sky just before dawn. From mid-northern latitudes the radiant is located low in the northwestern sky at dusk. It’s too low in the sky to bother watching unless you are watching from latitudes 60N or further north. As the night progresses the radiant skims the northern horizon and then begins to rise higher into the northeastern sky. It is best placed during the last hour before dawn when it is located high in the northeastern sky.

These are medium fast meteor comparable to the Lyrids of April. They are slower than the Perseids but faster than the Geminids. While not known to be a fireball source, I have seen Quadrantids as bright as magnitude -10, so the possibility exists that some extremely bright meteors may be seen.

This illustration above depicts the Quadrantid radiant as seen during the morning hours looking northeast. The brilliant star Arcturus is a good guide to this area of the sky. All Quadrantid meteors will trace back to the radiant area located in northern Bootes. From the southern hemisphere the radiant is located much lower in the northern sky therefore rates will be greatly reduced. There are several other minor showers active during this time plus random meteors that will appear in different paths than the Quadrantids with different velocities.

This is your last chance to witness a major meteor display under optimum conditions until early May. If your sky is clear don’t miss this opportunity!

 

 
 

Year in and year out the Geminids are currently the most dependable meteor shower. Unfortunately, they are active in December when temperatures are often cold and skies cloudy in the northern hemisphere. If this shower peaked in August it would be much more popular, but the radiant would then lie much closer to the sun and Geminid meteors would only be visible in the few hours preceding dawn.

These meteors are visible over the entire northern hemisphere and the southern hemisphere down to where it remains light around the clock. The best vantage point lies along the 30th parallel of north latitude, where the radiant passes overhead, usually between 01:00 and 02:00. There is not much change in rates the further north you go until you reach the polar regions. In the southern hemisphere rates fall precipitously the further south you are located due to the lower elevation of the radiant in the northern sky.

In December, the Geminid radiant lies nearly opposite the sun. Therefore, Geminid meteors are visible all night long from the northern hemisphere. In the southern hemisphere the radiant rises much later and is only above the horizon for a limited time (depending on your exact latitude) before the break of dawn.

The Geminids seen during the early evening hours are long and slow moving. The reason for this is that the Earth is just beginning to face toward the incoming meteors. They are just able to skim the upper portions of the atmosphere so they last longer in the thinner air and tend to create long paths in the sky. As the night progresses the Earth turns more directly toward Gemini and the meteors strike the atmosphere more directly creating shorter and quicker meteors, at least to our eyes. In fact, the Geminid meteors strike the Earth with the same velocity no matter what time it is. It’s our perspective from the ground that makes it seems that they change speeds and lengths.

Composite of Geminid Meteors – Dec, 14th, 2015 © Antoni Cladera / Photopills.com
Nikon D4s, 14mm, f2.8, 30s, 5000 ISO

The Geminids are produced by the comet/asteroid known as 3200 Phaethon. This object is classified as an Apollo asteroid but often acts like a comet by ejecting dust when it nears the sun. The Earth is near the orbit of 3200 Phaethon during the first three weeks of December. It comes closest to the core of the orbit on December 14th each year. This is the date most Geminid meteors are encountered and seen. When the Earth is near the edge of the orbital debris of the asteroid, little activity is seen. Unlike most meteor showers, the activity curve is asymmetrical. The climb to maximum activity is slower than the fall. Geminid activity is impressive for several nights prior to maximum but drops off quickly after December 14th.

To best see the Geminids you need to view as close to December 14th as possible. In 2018, the waxing crescent moon will be present in the evening sky. Geminid meteors can be seen with the moon in the sky but it is advised to keep your back to the bright moon so that your eyes can adjust to the darkness. Like all meteors showers, there are many more faint meteors than bright ones. Eyes that had just stared at the moon or just came outside from indoors will not be able to see these fainter meteors. Give your eyes time at adjust to the darkness. It is also advisable to watch for as long as possible as meteor activity waxes and wanes throughout the night. There will be periods when little activity is seen and then other periods when meteors are falling constantly. These periods often last as long as 15 minutes so it is advisable to watch for an hour or more so that you witness several peaks and valleys and get a real feel of the meteor activity.

Radar images of near-Earth asteroid 3200 Phaethon generated by astronomers at the Arecibo Observatory on December 17, 2017. The 2017 encounter was the closest the asteroid will come to Earth until 2093.

In order to view for that long, you need to be comfortable so a lounge chair is recommended. Lie back and view at a 45 degree (halfway up) angle to see the most activity. In the northern hemisphere be sure to have a blanket or two as December nights can be frosty. You can face in any direction as Geminid meteors can be seen in any part of the sky. No matter what part of the sky they appear, they will all trace back to the radiant near the bright star known as Castor (alpha Geminorum). As stated before, if the moon is above the horizon, keep it out of your field of view. You don’t have to know where Castor is located, but you will soon learn as meteor after meteor will shoot forth from that direction. Another item you will discover is that not all meteors will be Geminids. You will see some meteors, both faster and slower than Geminids, travel toward Gemini and in many other directions. Most of these will be random meteors that don’t belong to any recognizable shower. Some of the others will belong to minor showers that produce only a few meteors per hour.

It’s interesting and scientifically useful to categorize these meteors and total the hourly rates you witness from each source. You can share your results by filling out a meteor report form on the website of the International Meteor Organization (IMO) located here: VMDB

Lastly, you may wish to try and photograph the meteor activity. The Geminids are perfect subjects as the brightest meteors are often colorful and their slower speed allows more light to be recorded. You simply need a camera that can take time exposures in the range of 1 to 10 minutes. The darker the sky, the longer the exposure can be without being washed out. Stars will be pinpoints in short exposures but will trail across the frame in parallel paths in exposures exceeding a minute. Meteors will appear as straight streaks across your frame, often crossing star trails.

We hope you will attempt to view the Geminids, one of nature’s best light shows. We encourage all observers, regardless of experience, to share their observations with us!

 
 

The Geminid meteor shower is the favorite of most meteor observers as it usually provides the strongest display of the year. On the peak night (December 13/14) between the hours of 1:00 and 2:00am local standard time (LST), an observer located in mid-northern latitudes under clear skies has the opportunity to view at least 75 Geminid meteors. If you watch from a rural setting far from city lights then your counts could exceed 100. If watching from urban locations you will be limited to around 50 meteors during this period.

The Geminids are one of the few annual meteor showers that are active all night long. The radiant (the area of the sky where the meteors seem to come from) is located near the bright star Castor (alpha Geminorum). This star rises in the northeast near 1700 (5pm) LST as seen from mid-northern latitudes. At the time a few Geminid meteors may be seen streaking slowly upward toward the zenith or shooting parallel to the northern or southeastern horizons. These early Geminids are special as the geometry at this time of night only allows them to skim the top of the atmosphere. Therefore these meteors will last longer and will produced longer streaks in the sky compared to Geminids seen later on in the night. These meteors are referred to as “earthgrazers”. The number of meteors seen at this time will be low, but they will be impressive nonetheless.

Geminids 2017 Radiant

As the night progresses the Geminid radiant will rise higher into the sky. The meteors will seem quicker and shorter than those seen at dusk. Their numbers will also increase with each passing hour. The display really kicks into high gear around 2200 (10pm) LST when the radiant reaches the halfway point between the horizon and the zenith (straight up). The radiant will lie highest above the horizon near 0200 LST. This will be the best time to view activity as the radiant will lie overhead and Geminid meteors will be shooting downward in all directions. This is also the only good time to view the Geminids from the southern hemisphere. As seen from latitude 25S, the radiant will lie 1/3 the way up in the northern sky. Viewers there will only be able to see half the activity compared to mid-northern locations. As the morning progresses past 0200 LST the radiant will set into the western sky and rates will fall with each passing hour. As dawn breaks the radiant will lie low in the west.

Your average Geminid meteor is usually as bright as the brighter stars, 2nd or 3rd magnitude. Of course it all depends on the darkness of your sky. Rural observers will be able to see more faint meteors while urban observers are limited to seeing only the brighter ones. Brighter Geminid meteors can produce a color, usually yellow or orange. Fireballs (extremely bright meteors) occur more often during the Geminids and some of these are intensely green or blue. See the featured picture for a great example!

The Geminids are easy to photograph as they are bright and slower moving than most meteors. Any camera that can expose for a minute or longer can capture meteors. Meteors will appear as straight streaks on your pictures. Star trails will be curved. The best area to aim a camera is not straight up but toward the darkest direction available with the camera aimed half-way up in the sky.

People often ask where to look in the sky for meteors. Meteors will appear in all areas of the sky but are best seen away from bright lights that affect your vision. Also, don’t look straight up, rather look roughly half-way up in the sky, high enough to avoid hills or trees that may block your view. Also important is to be comfortable and don’t stand and watch. Sit in a comfortable chair aimed toward your darkest direction. Meteors will appear in bunches so there will be periods of no activity and times of high activity. This is why we suggest watching for as long as possible. This will assure that you will see both slow and strong activity and not just some short period of inactivity. Even under the darkest skies there will be periods as long a 5 minutes when no activity is seen. Just a quickly though you may see 5 meteors in quick succession. It’s also important to remember that you do not need any optical equipment such as a telescope to see meteors. Your unaided eyes offer a wide field of view which is important in catching these swift streaks of light.

Not all the meteors you see will be members of the Geminid shower. There are also other weaker minor showers active this time of year in Taurus (Taurids), Monoceros (Monocerotids), Vela (Puppid-Velids), Hydra (Sigma Hydrids), and Leo Minor (December Leonis Minorids). These meteors will appear differently than the Geminids as they possess different velocities and will have different tracks across the sky.

If the night of December 13/14 is cloudy don’t despair. The Geminids are strong for several nights, most notably during the couple of nights leading up to maximum activity. So if the forecast is cloudy on the night of maximum try to view on the 11/12 and 12/13. One can also view on the 14/15 but rates will have fallen drastically by then.

The Geminids reappear each year during the first half of December when the Earth passes though stony debris left behind by the asteroid known as 3200 Phaethon. This shower and the Quadrantids of January are the only major showers known to be produced by asteroids. Last year’s Geminid maximum display coincided with a full moon which severely limited the number of meteors visible. This year the moon will be a thin waning crescent phase and will rise during the latter part of the night. Therefore it will not be a problem as long as you view before moon rise or look away from the moon once it clears the horizon. So don’t waste this opportunity to see an impressive display of natural fireworks!

 
 

The Orionids

The Orionids, like all meteor showers, are named after the constellation in which they appear to come from, which in this case is Orion. Remnants from this shower come from Halley’s Comet, officially designated 1P/Halley. Halley’s Comet is the only known short-period comet that is clearly visible to the naked eye from Earth. This comet swings by the sun every 76 years. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061. The current orbit of Halley’s Comet does not intersect the Earth so the Orionid meteors we see today were left behind by the comet many years ago. Meteoroids (meteors orbiting in space) are subject to perturbations when they pass close to the planets. This makes it difficult to predict just how densely populated the meteoroids are when then intersect the Earth. Therefore it is also difficult to predict just how active the Orionids will be year to year. The latest research believes that the Orionids are in a 12 year cycle with a particle resonance with Jupiter, independent of the much longer orbit of Halley’s Comet. The last cycle peaked in 2006, when Orionid activity match the normally stronger Perseids. Rates have been low during the first half of the 2010’s so the hope is that activity will be on the increase the next few years.

Halley_s_Comet

Halley’s Comet © ESA

Where? When? How many?

Current Orionid rates should be currently near 10 per hour during the last few hours before dawn. This should increase to 20-25 meteors per hours near maximum activity, which occurs on October 22. Unlike most major annual showers, the Orionids have a flat maximum where strong rates occur over several nights centered on October 22. Therefore, if you are clouded out on the morning of October 22, don’t despair as good rates will continue for a few more nights. Good rates can be see equally well before the maximum too!

If you watch the same place in the sky all Orionid meteors will have the same characteristics. They will move in parallel paths and will posses the same velocity. These paths will lead back to the radiant in Orion. These characteristics change if you look somewhere else. In general, Orionid meteors will appear to be swift unless you see them near the radiant or near the horizon. Also the paths will appear shorter near the radiant and near the horizon. Therefore it is advisable to have the Orionid radiant near the edge of your field of view so that you will see longer meteors. There are also minor radiants active in Gemini, Leo Minor, and Aries this time of year.

The radiant, located on the Orion-Gemini border, rises near 2200 (10pm) local daylight saving time. This is not the best time to see them though as some of the activity will occur beyond your line of sight. I would be better to wait until after midnight when this area of the sky has risen higher into the sky. At that time Orionid meteors can be seen shooting in all directions. As is standard for most meteor showers, the best time to watch this shower will be between the hours of midnight and dawn – regardless of your time zone. With the radiant lying just north of the celestial equator, this allows the Orionids to be seen all over the Earth except from Antarctica, where daylight/twilight persists for 24 hours.

This year, the waxing crescent moon sets well before midnight on October 21, leaving the morning hours dark for meteor watching! In the predawn and dawn sky, look for Sirius, the sky’s brightest star as a guide. The bright constellation of Orion lies above Sirius and the Orionid radiant lies just to the upper left of the main part of Orion.

orionids

Orionids’ radiant – SouthEast after Midnight

Meteor Shower?

Most meteor showers have their origins with comets. Each time a comet swings by the sun, it produces copious amounts of meteoroid sized particles which will eventually spread out along the entire orbit of the comet to form a meteoroid “stream”. If the Earth’s orbit and the comet’s orbit intersect at some point, then the Earth will pass through this stream for a few days at roughly the same time each year, encountering a meteor shower.

Because meteor shower particles are all traveling in parallel paths, at the same velocity, they will all appear to radiate from a single point in the sky to an observer below. This radiant point is caused by the effect of perspective, similar to railroad tracks converging at a single vanishing point on the horizon when viewed from the middle of the tracks.

 
 
Most people have heard of the Perseid meteor shower, known for producing celestial fireworks every summer in the northern hemisphere. What they don’t often know is what causes this display and what causes it to produce varying levels of activity year to year. We see Perseid meteors when the Earth intersects the orbits of comet 109P/Swift-Tuttle. I mention “orbits” because the comet does not take exactly the same path each time it passes through the inner solar system. When the Earth happens to pass through the center of one of these paths we witness enhanced activity from the Perseids. Most of the time it passes between these paths. The meteors we seen in our skies are actually tiny particles of ice and dust that are released by the comet each time it passes near the sun. They strike the earth’s atmosphere at high velocity of 37 miles per second. At that speed all Perseid meteors disintegrate while still high in the upper atmosphere. Larger Perseid particles produce fireball class meteors and persistent trains that remain in the sky a few seconds after the meteor has disappeared.
 
The Earth begins to enter the outer edges of the paths of comet 109P/Swift-Tuttle around July 17 and leaves it around September 1st. We are closest to the core around August 12. This is when you will see the most activity. The number of particles in orbit are much greater than for most streams therefore we see more activity from this shower than most others. The closer you view to August 12, the more Perseid activity one will see. There is one other factor that comes into play year to year and that would be the moon. A great majority of the particles the Earth encounters are very tiny and produce meteors so faint that they are invisible to the naked eye. Of course there are Perseid meteors bright enough to be seen but most of these are also faint. If you try and view the Perseids with a bright moon in the sky the moonlight will obscure these fainter meteors. Unfortunately this is the case this year with a full moon occurring on August 7th. By the time the 12th arrives the moon will have waned to approximately 80% illuminated. This is not much better than a full moon and will certainly pose a challenge in viewing the Perseids this year. To alleviate this problem one could try to view the display before the moon rises, which would be approximately 10pm local daylight saving time on the evening of the 11th. Unfortunately at that time the Perseid radiant, the area of the sky that Perseid meteors appear to shoot from, is located low in the northern sky and the number of meteors seen is the lowest. However, these meteors tend to be very long and long-lasting so it is definitely worth trying to see some of them. Once the moon has risen, it would be advisable to face away from it so that you save your night vision and face the darker portions of the sky where more activity can be seen. Perseid meteors can be seen in all parts of the sky. If you focus on one part of the sky then Perseid meteors will all have similar paths and velocities, only the brightness will be different. This gradually changes throughout the night, depending on the position of the radiant in Perseus.
 
The best time to see Perseid activity is when the radiant lies highest above the horizon in a dark sky. For most potential observers this occurs near 4am local daylight saving time. At this time you should be able to see 20-30 Perseids per hour, depending on the transparency of your sky. These rates are better than most of the major annual showers so it is definitely worth trying to view the display this year despite the moonlight. There will also be other meteors visible besides the Perseids. These meteors will be far less numerous and will possess varying velocities and paths through the sky. If you are clouded out on the evening of August 11 or the morning of the 12th, meteor activity will still be good the following night and for a few nights after. The good news for Perseid observers is that the 2018 display will occur near a new moon, when the moon is located near the sun and not visible at night.
 
We encourage observers to not only view this display but to make scientifically useful hourly counts of the meteors you see.  Helpful hints on how to do this are available at: http://www.imo.net/observations/methods/visual-observation/
 
Clear Skies!
 
 

Eta Aquariid meteors as seen from mid-northern latitudes just before dawn

Eta Aquariid meteors as seen from mid-northern latitudes just before dawn

The Eta Aquariids (ETA) are active between April 19 and May 28. The strongest activity is usually seen near May 7, when rates can reach 25-30 meteors per hour as seen from the tropical areas of the Earth. Unlike most major annual meteor showers, there is no sharp peak for this shower, but rather a plateau of good rates that last approximately one week centered on May 7. The Eta Aquariids are particles from Halley’s Comet, which last passed through the inner solar system in 1986. The meteors we currently see as members of the Eta Aquariid shower separated from Halley’s Comet hundreds of years ago. The current orbit of Halley’s Comet does not pass close enough to the Earth to be a source of meteoric activity.

For most observers, the Eta Aquariids are only visible during the last couple hours before the start of morning twilight. The reason for this is that the radiant is situated approximately sixty degrees west of the sun. Therefore it rises before the sun in the morning hours. The time of radiant rise is between 2:00 and 3:00 local daylight time (LDT), depending on your longitude. The real key is the latitude. There is an observing window for this shower between the time the radiant rises and the beginning of morning nautical twilight. This window ranges from zero at 60 degrees north latitude to all night in Antarctica. Unfortunately in Antarctica, the radiant never rises very high in the sky. The best combination of a large observing window and a decent radiant altitude occurs between the equator and 30 degrees south latitude. From this area the radiant reaches a maximum altitude of 50 degrees at nautical twilight. The observing window ranges from 3.5 hours at the equator to slightly over 4.0 at 30 degrees south latitude. Going further south will increase your observing window but the maximum altitude will begin to fall closer to the horizon.

Since most meteor observers live in the northern hemisphere, here are the conditions at several different latitudes: the observing window for 50N is 1.5 hours with a radiant altitude of 15 degrees. The observing window for 40N is 2.25 hours with a radiant altitude of 25 degrees. The observing window for 30N is 2.75 hours with a radiant altitude of 35 degrees.

In 2016, the moon will be at its new phase when the shower is predicted to peak. These are very favorable conditions as the moon will not be visible at night and will not interfere with viewing this activity. To see the most activity observe after the radiant has risen and look approximately half way up in the sky toward the east. If this direction is heavily lit with light pollution then switch closer to the north or south. If facing east the Eta Aquariid meteors will enter your field of view from the bottom. If facing north then they will enter from the right and facing south they will enter from the left. Meteors moving in any other direction would be sporadic or those belonging to a minor shower active at this time. Near maximum, the radiant may be easily spotted as it lies near the “water jar” in Aquarius. This “Y” shaped pattern of stars is also known as the “peace sign” to some observers. It should be noted that very few meteors are actually seen at the radiant. This position just happens to be the apparent source of the activity. More activity is seen further up in the sky where longer shower members can be seen. That is why it is advised to look half-way up in the sky. Do not look straight up as this is the direction of least meteoric activity. By looking at the zenith you are looking though the thinnest slice of atmosphere possible. This is great for lunar and planetary viewing but not for meteor observing. Have the horizon be at the bottom of your field of view and your center will lie near the optimal forty-five degree altitude zone.

If you would like to contribute more to our knowledge of the Eta Aquariids, then I invite you to get serious about meteor observing and to make an hourly count of the activity you witness. Be certain to at least separate the Eta Aquariids from other meteors. It is also interesting to look for the Anthelion meteors and for members of the Eta Lyrids, both are weakly active during the Eta Aquariids. Other more detailed projects include the estimating the magnitude, velocity, and color of each meteor. Others also note whether there was a persistent train after the meteor has vanished. Meteor watching can be both fun and scientifically useful endeavor. To be scientifically useful you must share your data with an active meteor organization such as the Association of Lunar and Planetary Observers. We accept data from observers with all levels of experience. You can send your data to the Meteors Section recorder via email. Members of the International Meteor Organization can also use their online observing report to share your data.

We look forward to hearing from you!

Robert Lunsford

Meteors Section Recorder

Association of Lunar and Planetary Observers

Eta Aquariid meteors as seen from mid-southern latitudes just before dawn

Eta Aquariid meteors as seen from mid-southern latitudes just before dawn

 
 
Quadrantids
Quadrantids radiant seen near 5am EST on Jan 4 from the US East Coast

Ever wonder why the moon is mentioned so often in reports on this website? The reason is simple; the visibility of a meteor shower depends greatly on the phase of the moon. An observer will see many more meteors in a moonless sky than one with a full moon. Contrary to popular belief, most of the meteors we see in the sky are on the faint side, equivalent to 3rd or 4th magnitude stars. These meteors are easily obscured by moonlight, especially if the sky is hazy. While successful meteor watching sessions can be carried out with a moon in the sky, you will see more activity on moonless nights or when the phase is thin.

As for the Quadrantid meteor shower of 2016, this shower is predicted to peak on Monday morning January 4th over North America and the western Atlantic rigion. On that morning the 30% illuminated moon will rise at approximately 0200 (2am) local standard time for most observers in the northern hemisphere. This timing will vary according to your exact location. 30% does not sound like much but if your face toward the moon during your observations it will be a nuisance and will cause you to miss some fainter meteors. If the moon is above the horizon during your Quadrantid observations I would advise you to face toward the northern half of the sky with the moon at your back.

This shower has a very sharp peak that is predicted to occur near 4am AST, 3am EST, 2am CST, 1am MST, and midnight PST. The moon will be above the horizon for the eastern half of North America. While the western half may have darker skies, the radiant (the area of the sky where Quadrantid meteors come from) will be located lower in the sky. This means that there will be less activity. So despite the moonlight, the east half of North America will be favored for this display if it occurs at the predicted time.

As you see from the chart above, the Quadrantid radiant is located in a blank part of the sky. The nearest recognizable star pattern is the Big Dipper, which is part of the constellation Ursa Major. Quadrantid meteors can be seen in all parts of the sky but they will all trace back to this radiant area. These meteors possess medium speeds and the brighter members can produce persistent trains which linger after the meteor itself has vanished. Not all meteors you see on Monday morning will be Quadrantids. There are minor showers and random meteors also active which should add at least 10 meteors per hour to your totals.

A good viewing strategy would be to watch for at least an hour centered on the times above. This prediction is based on returns of this shower for the last 20 years but it may be off by an hour or two. If the maximum occurs earlier then activity will be far less for everyone in North America. If it is late then the entire continent has the opportunity to see an excellent display. This shower has the potential to produce in excess of 100 meteors per hour if viewed from rural locations. Unfortunately these rates are rare and we usually end up seeing a peak of around 25 Quadrantids per hour. If you view from the eastern half of North American and your rates are low at the predicted time then try to stay out longer as the activity may still be on the increase. So if your skies are clear on Monday morning then bundle up and and try your luck at seeing some celestial fireworks!

quad_pic
Long exposure photo with several Quadrantid meteors from Florida Keys – Jan. 2, 2012 © Jeff Berkes.

I should also mention that there is another prediction for an earlier peak that is favorable for European observers. So before you head out you may wish to check the internet to see if strong rates were seen over Europe. If the peak occurs over Europe then there will be little activity left for North American observers.

History

When the first report of the Quadrantids came public (around 1825), the radiant appeared in the constellation Quadrans Muralis, located between the constellations Draco and Boötes. In 1922, the International Astronomical Union formed a list of modern constellations and elected not to include Quadrans Muralis. As the name “Quandrantids” remains, some astronomers suggest the meteor shower could new be called the Boötids,since the radiant falls in the constellation Boötes. However, there is already a meteor shower by that name, which occurs in late June in the Northern Hemisphere.

Quadrans Muralis can be seen at the top left of this 1825 star chart from Urania's Mirror.
Quadrans Muralis can be seen at the top left of this 1825 star chart from Urania’s Mirror (1824).

Parent Body

The Quadrantid meteor shower influx is sharply peaked: six hours before and after maximum, these meteors appear at only half of their highest rates. This means that the stream of particles is a narrow one, possibly derived relatively recently from a small comet. The parent body of the Quadrantids was tentatively identified in 2003 by Peter Jenniskens as the minor planet 2003 EH1, which in turn may be related to the comet C/1490 Y1 that was observed by Chinese, Japanese and Korean astronomers some 500 years ago.

 
 
 
fireball
Fireball over the Mojave Desert (Southern California)- © Wally Pacholka – December 14, 2011.

The Geminid meteor shower is the favorite of most meteor observers as it usually provides the strongest display of the year. On the peak night (December 13/14) between the hours of 1:00 and 2:00am local standard time (LST), an observer located in mid-northern latitudes under clear skies has the opportunity to view at least 75 Geminid meteors. If you watch from a rural setting far from city lights then your counts could exceed 100. If watching from urban locations you will be limited to around 50 meteors during this period.

The Geminids are one of the few annual meteor showers that are active all night long. The radiant (the area of the sky where the meteors seem to come from) is located near the bright star Castor (Alpha Geminorum). This star rises in the northeast near 1800 (6pm) LST as seen from mid-northern latitudes. At the time a few Geminid meteors may be seen streaking slowly upward toward the zenith or shooting parallel to the northern or southeastern horizons. These early Geminids are special as the geometry at this time of night only allows them to skim the top of the atmosphere. Therefore these meteors will last longer and will produced longer streaks in the sky compared to Geminids seen later on in the night. These meteors are referred to as “earthgrazers”. The number of meteors seen at this time will be low, but they will be impressive nonetheless.

Geminids radiant
Geminids radiant

As the night progresses the Geminid radiant will rise higher into the sky. The meteors will seem quicker and shorter than those seen at dusk. Their numbers will also increase with each passing hour. The radiant will lie highest above the horizon near 0200 LST. This will be the best time to view activity as the radiant will lie overhead and Geminid meteors will be shooting downward in all directions. This is also the only good time to view the Geminids from the southern hemisphere. As seen from latitude 25S, the radiant will lie 1/3 the way up in the northern sky. Viewers there will only be able to see half the activity compared to mid-northern locations. As the morning progresses the radiant will set into the western sky and rates will fall with each passing hour. As dawn breaks the radiant will lie low in the west.

Your average Geminid meteor is usually as bright as the brighter stars, 2nd or 3rd magnitude. Of course it all depends on the darkness of your sky. Rural observers will be able to see more faint meteors while urban observers are limited to seeing only the brighter ones. Brighter Geminid meteors can produce a color, usually yellow or orange. Fireballs (extremely bright meteors) are common during the Geminids and some of these are intensely green.

The Geminids are also easy to photograph as they are bright and slower moving than most meteors. Meteors will appear as straight streaks on your pictures. Star trails are curved. Any camera that can expose for a minute or longer can capture meteors. The best area to aim a camera is not straight up but toward the darkest direction available with the camera aimed half-way up in the sky.

People often ask where to look in the sky for meteors. The first thing I tell them is to be comfortable and don’t stand and watch. Sit in a comfortable chair aimed toward your darkest direction. Meteors will appear in all areas of the sky but are best seen away from bright lights that affect your vision. Also, don’t look straight up, rather look roughly half-way up in the sky, high enough to avoid hills or trees that may block your view. Meteors will appear in bunches so there will be periods of no activity and times of high activity. This is why we suggest watching for as long as possible. This will assure that you will see both slow and strong activity and not just some short period of inactivity.

stargazers
The Dark Sky Viewing Area offers a night sky experience very similar to what was available more than 100 years ago. (photo © Terence Dickinson)

Not all the meteors you see will be members of the Geminid shower. There are also other weaker minor showers active this time of year in Orion (Anthelions), Monoceros (Monocerotids), Vela (Puppid-Velids), Hydra (Sigma Hydrids), and Leo Minor (December Leonis Minorids). These meteors will appear differently than the Geminids as they possess different velocities and will have different tracks across the sky.

If the night of December 13/14 is cloudy don’t despair. The Geminids are strong for several nights, most notably the weekend of the 12/13. So if Sunday night/Monday morning look to be cloudy then watch earlier. Monday night/Tuesday morning will be good too but weaker than rates seen over the weekend.

The Geminids reappear each year in mid-December. Unfortunately the display in 2016 will occur with a full moon in the sky, severely limiting the number of meteors seen next year. Not until December 2017 will the Geminids appear under favorable conditions again. So don’t waste this opportunity to see an impressive display of natural fireworks!

 
 

taurids2

Taurids radiants

Every October and November the two branches of the Taurid meteor shower become active. The Taurids are not known for their high numbers, rather they are known more for the fireballs they produce. Occasionally there are more Taurid fireballs than normal. 2015 may be such a year. These increased numbers of fireballs are due to the fact that the Earth encounters larger than normal particles shed by comet 2P/Encke, the parent comet of the the Taurids. These fireballs are thought to be active between October 29 and November 10. Luckily, this at time of year the area of which these meteors appear to come from lies above the horizon all night long. During the evening hours Taurid meteors will shoot upwards from the eastern sky. Near midnight they sill shoot from an area high in the southern sky (as seen from mid-northern latitudes). In the late morning hours they will shoot upwards from the western sky. Unlike most meteors, the Taurids are not fast. The fireball class meteors are usually vividly colored and may fragment before they completely disintegrate. Not every meteor or fireball will be a Taurid as there are other minor showers active plus random activity.

We encourage you to report any fireballs you may witness. If you happen to see one of these bright meteors, we invite you to fill out a fireball report at: fireball report.

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