Meteor Section        

 
 

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.

 
 

Examples of Perseid meteors as seen at 4am local daylight time while facing northeast.

Examples of Perseid meteors as seen at 4am local daylight time while facing northeast from mid-northern latitudes.

Unlike last year when the Perseid maximum was subdued by the intense moonlight from the full moon, the Perseids in 2015 peak under ideal conditions with a new moon occurring on August 15th. Another positive note is that astronomers expect an above average display peaking over American longitudes. Another highlight is the possibility of enhanced rates for several hours centered on 19 Universal Time, which is favorable for Asian longitudes.

The Perseids first begin to encounter the Earth near July 13th, when members of this stream who have been perturbed from the main orbit first begin to appear. Rates remain below 5 per hour throughout July but then increase dramatically beginning the second week of August. Rates reach 10 per hour near August 8th and 20 per hour near the 10th. The morning of the 11th should produce rates near 30 per hour and the 12 near 50. On the night of maximum activity rates could peak anywhere from 80-120 per hour. After maximum rates fall rapidly and are back down to 5 per hour by the 17th.
The key to success in viewing the Perseids is to view from skies as dark as possible. This often means travelling to rural sites but the dramatic increase in activity you will experience is well worth it. Observers in the western portion of North America also have an added advantage of transparent skies. The dry air is more transparent compared to hazy conditions therefore fainter meteors can be seen.

On the night of maximum activity the Perseid radiant is located at 3:12 (140.1) +58. This position lies near a point where the constellations of Perseus, Camelopardalis, and Cassiopeia meet. The closest recognizable star is 4th magnitude Eta Persei, which lies 4 degrees to the southwest. The closest bright star is 2nd magnitude Mirfak (Alpha Persei) which lies 7 degrees south of the Perseid radiant. This area of the sky lies at its lowest point at sunset. Therefore the evening hours will produce little Perseid activity. The Perseid meteors you do see at this time are called “Earthgrazers” as they just skim the atmosphere above you. These meteors are few but they last for several seconds and often streak across a long portion of the sky. As the evening progresses the Perseid radiant rises into the northeastern sky and more activity will begin to appear. By midnight, the radiant will have reached a sufficient altitude to begin serious observations. The highest activity will occur between 3:00-4:00am local daylight saving time when the Perseid radiant lies highest in a dark sky. Perseid meteors will appear in any part of the sky but they will all trace back to the radiant. Not all meteors appearing that night will be Perseids. There are several minor showers also active at that time plus you can count on at least a dozen random meteors appearing each hour.

Meteor showers produce activity in “clumps”. This means that there will be periods when no activity is seen followed by periods of intense activity. This is why we urge observers to view for at least an hour so that a good sampling of activity can be seen. If you stand outside and watch for only 15 minutes, you might be watching during one of the lulls and will be disappointed with what you witness. Watching for longer periods of time ensures that you see both the peaks and valleys of activity. For extended watching it is highly suggested that you lie in a comfortable lawn chair. This will save your neck muscles and will produce a much more enjoyable experience compared to standing up.

A majority of the meteor activity seen above will occur in the lower half of the sky. The reason for this is that when viewing lower in the sky you are looking through a thicker slice of the atmosphere. Viewing straight up presents the thinnest slice of air therefore less meteors. One problem with viewing lower in the sky is that the lower portion of your field of view is wasted on the ground. The best strategy would be to view high enough in the sky so that you cannot see the ground, hills, or trees that would prevent you from seeing meteors. Aiming about half-way up in the sky is the best all around compromise for seeing the most activity.
Perseid meteors appear in all ranges of brightness ranging from barely detectable to blinding fireballs. Unfortunately dim meteors are much more numerous than bright ones. This is why we urge observers to view from dark rural locations away from city lights. The brighter Perseid meteors can also exhibit vivid colors. The colors most mentioned for the Perseids are orange and yellow. These colors are most likely produced by sodium present in the meteoroids. The brighter Perseids can also exhibit a phenomenon known as persistent trains. These appear as smoke trails that remain after the meteor has disappeared. These are not really smoke, but a column of gas that glows after the passage of the meteor. If the train lasts long enough it can be seen twisting and turning in the winds of the upper atmosphere.

While the ALPO Meteors Section urges you to view meteor activity, we also wish for you to share your experience with us. This can range from general descriptions to detailed reports on each meteor witnessed. Send your reports via email to: lunro.imo.usa@cox.net.

We look forward to hearing from you!

 

 

 
 

Examples of Lyrid activity seen on April 23, from 40 N latitude, just before dawn while facing north.

After three months of low rates, April ushers in two major showers and a temporary upswing in meteor activity. The first of these showers is the Lyrids, which are active from April 16 through the 25th. Activity for this shower is low away from the peak night which expected to occur on April 22/23. Peak rates are predicted to occur near 4:30 Universal Time on April 23, which corresponds to 0030 EDT and 2130 PDT (on the 22nd). This timing is better for the eastern portion of North America as the Lyrid radiant will lie higher in the sky. Rates seen from the western half should not be that much lower so all of North America is well placed to view this display. Average ZHR’s are eighteen for this shower so visual rates in excess of ten per hour should be seen from North America on the morning of the 23rd.

On the night of maximum activity the Lyrid radiant is actually located in eastern Hercules, seven degrees southwest of the brilliant star Vega (Alpha Lyrae). This area of the sky lies below the horizon during the early evening hours. It attains a decent elevation between midnight and 0100, depending on your latitude. It is best situated high in a dark sky just before the start of morning twilight. While the Lyrids are not the strongest shower, it is notable that shower members will occasionally reach fireball intensity.

On the night of maximum activity the moon will be at its waxing crescent phase and will have set by the time the radiant reaches a decent altitude. Lunar conditions could not be much better for this display. Observers in the Southern Hemisphere will see very little Lyrid activity as the radiant will be located low in the northern sky. All Lyrid meteors will trace back to the radiant area in eastern Hercules. There will be other showers and random activity visible during this period so not all meteors will be members of the Lyrid shower. Lyrid meteors will appear to travel swiftly through the sky unless they are seen near the radiant or near the horizon. Lyrids seen there will move more slowly as they are moving towards you (if seen near the radiant) or away from you (if seen near the horizon).

The Lyrids are particles from Comet Thatcher (C/1861 G1). This comet has an orbital period of 415 years and the last time it was a perihelion was back in 1861. This shower has produced several notable outbursts. These occurred in the years 1803, 1849, 1850, 1884, 1922, 1945, and 1982. The 1803 event seems to the strongest as rates exceeded 500 Lyrids per hour at maximum. The 1982 event was seen from eastern USA where rates were estimated near 100 per hour at maximum. I witnessed the final portions of this outburst as I drove out to dark sky site. Lyrid meteors were seen shooting upward from the northeastern horizon. Once I arrived at my site the outburst was over and very little activity was seen the remainder of the night. The next possible outburst for this shower is predicted to occur in 2040 and 2041.

 
 

Examples of Ursid meteors seen just before dawn while facing north

The week before Christmas is not one usually devoted to meteor observing. That is unfortunate as an obscure shower known as the Ursids reaches maximum activity during this period. It is not a strong display like the Geminids, but is capable of producing 10-15 shower members per hour under ideal conditions. Luckily this year the moon is not a factor. I have seen the Ursids as high as 25 per hour from the low latitudes of southern California. This shower is expected to reach maximum activity near 1600 Universal Time on December 22nd. This corresponds to 11am EST and 8am PST. Obviously locations further west such as Alaska are more favored to see Ursid activity. There also exists the possibility that another small display of activity may also occur later near 0040 UT on the 23rd. This corresponds to 2200 (7:40 pm) EST and 1900 (4:40 pm) PST on the evening of December 22nd. Locations further east are favored for this activity. Don’t expect much from this secondary maximum as the dust trail is over 600 years old. The Ursid radiant, located near the bright orange star Kochab (Beta Ursae Minoris), is also better situated higher in the morning sky during the morning hours. Rates are weak away from maximum so do not expect to see more than 1-2 per hour on any morning other than December 22nd. It would be wise to face toward the northern half of the sky to view these meteors. While some activity can be seen toward the south, more meteors will be shooting downward and sideways out of the radiant and cannot be seen if facing south. These meteors are slightly slower than the Geminids and have a different look to them compared to other showers. It is also unusual to see such activity from such a northern radiant. This also prevents these meteors from being visible from the southern hemisphere.

If your skies are clear on Monday, you should try viewing some of this activity!

 
 

Geminid Meteors seen at 7pm

Geminid Meteors seen at Midnight

Geminid Meteors seen at 5am


The Geminid meteor shower is now active and will reach maximum activity on Saturday evening/Sunday morning December 13/14. Activity is currently low with less than 5 meteors per hour appearing from this source. Rates are usually twice this number but the nearly full moon obscures all but the brightest meteors. Activity will increase each night until maximum activity is reached on the 13/14. After maximum, rates will fall swiftly and Geminid meteors will soon disappear.

On the night of December 13/14, Geminid meteors will appear as soon as becomes dark. Activity will be low but the meteors you see will be long and long-lasting. They will shoot from the northeastern horizon in all directions. Most of them will hug the north or southeastern horizon. Occasionally you will see one shooting straight up and these will be a real treat.

As the night progresses the Geminid meteors will become shorter and will move in all directions, including downward toward the eastern horizon. Activity will also increase as the Geminid radiant (the area of the sky Geminid meteors appear to shoot from) climbs higher into the eastern sky. Near 10pm local standard time (LST), the Geminid radiant will lie approximately half-way up in the eastern sky. At this time viewers from the city can expect to see 10-20 Geminids per hour. If you live in the suburbs then hourly rates should be 20-30 Geminids per hour. If you live in rural areas then hourly rates should be 30-40 Geminids per hour. The reason for this difference is that most of the Geminid meteors are faint. Faint meteors, just like faint stars, are obscured by city lights. The darker your environment, the more meteors you will see.

Geminid activity will continue to increase until around midnight, when the half-illuminated moon rises in the east. Rates near 60 Geminid meteors should be seen between midnight and 2am from rural locations. After that, the Geminid radiant begins to set in the western sky and the moon gains altitude in the east. Geminid rates will then begin to fall due to the increased intensity of the moonlight and the declining horizon distance. Geminid meteors, like all shower meteors, will appear in “clumps”. One may see nothing for 5 minutes and then see 5 meteors within the next minute. This is why it is important that observers watch for as long as possible. If you watch for a short time you may be watching during a slump in activity and will be disappointed.

Not all meteors seen this time of year are Geminids. There are other minor showers active which are both faster and slower than the Geminids. There are also random meteors not associated with any known shower. Roughly 80% of the meteors should be Geminids on December 13/14. This percentage will be less on nights away from maximum. Geminid meteors are of medium speed and their average duration is on the order of a half-second. Brighter Geminids will last longer and Geminid fireballs can last several seconds and exhibit brilliant colors such as orange and green.

I would advise potential viewers not the wait until December 13/14, just in case this night is cloudy. The night of December 11/12 is good and the 12/13th is almost as good as the night of maximum activity. Rates will fall by at least 50% each night after maximum.

Viewers all over the world can see this display of meteors. The only continent where the display is invisible is Antarctica. From there the radiant never rises above the horizon plus daylight lasts 24 hours this time of year. Viewers in the northern hemisphere have a distinct advantage as the nights are longer plus the Geminid radiant rises higher into the sky. Observers in Australia, southern Africa, and South America can best see Geminid activity near 0200 LST or 0300 local daylight saving time, when the radiant lies highest in their northern sky.

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