Meteor Section        

 
 

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.

Conditions for viewing the Perseids are not favorable this year. The full moon will occur on August 10 and the shower peaks only 3 nights later. Yet I would still make an effort to view meteor activity on the nights of August 12 and 13 despite the less than favorable conditions. The Perseids are a strong shower that produces many bright meteors. Despite the bright moonlight an observer should be able to see at least 20 Perseids per hour between midnight and dawn. These are better rates than 95% of all other nights regardless of lunar conditions. Therefore if your skies are clear these nights, make an effort to see this display of celestial fireworks.

As the sun sets in mid-August, the Perseid radiant lies near the northern horizon for viewers located in mid-northern latitudes. This is certainly not the prime time to view Perseid activity but it may be worth your effort to try and catch some Perseid earthgrazers at this time. This year on the night of August 12/13, the 90% illuminated moon will rise at approximately 21:00 or 9pm local daylight time. With the moon low in the east its brilliance will be diminished by the atmosphere. For an hour or so beginning at the time you can see stars in the dimming skies, you have the opportunity to see Perseid meteors that just skim the upper atmosphere. These are much different than Perseid meteors you see later in the night. With less resistance from air molecules these meteors last much longer and create long trails across the sky, often nearly stretching from horizon to horizon. With the low radiant altitude there will not be many of these meteors to see. Any that you do manage to witness will be memorable. Sky & Telescope magazine has a nice article on these meteors in their August 2014 issue.

As the night progresses the Perseid activity will continue to be low as the moon rises higher in the sky, attaining it full brilliance. Not until after midnight will the Perseid radiant gain sufficient altitude to produce pleasing results. Anytime from midnight to dawn will be the best time to see the most activity. I would suggest facing away from the moon and concentrate your view at approximately one-half the way up in the sky. Most of the faint Perseids will be obscured by the bright moonlight. But the bright meteors you do manage to see will often be colorful and the brightest may leave persistent trains that remain in the sky after the meteor itself has disappeared.

If your skies are cloudy on August 12 or 13, the following nights should also produce decent activity with the moon rising slightly later in the evening. Note that the activity will fall approximately 50% each night after maximum so there will not be much left of this shower by the time the moon is out of the way. The two nights prior to maximum are usually good too but the moon will be closer to full and will lie above the horizon the entire night.

Regardless of what night you view, be sure to share your counts and impressions of the display with us!

 

 
 

These are examples of Delta Aquariid activity seen from 40 degrees north latitude while facing south near 0300 local daylight time on July 30.

These are examples of Delta Aquariid activity seen from 20 degrees south latitude while facing south near 0200 local standard time on July 30.

While the Eta Aquariid meteor shower produces the strongest hourly rates seen from the southern hemisphere, it is the Delta Aquariids (SDA) that produces the most total activity during its entire activity period. The Delta Aquariids (aka Southern Delta Aquariids) can be successfully observed from the northern hemisphere but their numbers are reduced due to the lower radiant altitude.

This shower is active for more than a month stretching from July 21st through August 23rd. Some other studies have stretched this period from July 19th through September 3rd, but shower membership of possible SDA’s at these extremities are dubious at best. Peak rates occur on July 29 or 30 with stated ZHR’s of 15-20. I have personally seen hourly rates of 25 from latitude 33 N. and experienced observers have seen hourly rates as high as 40 from equatorial locations. Of course these rates were seen under near perfect skies where faint meteors made up a majority of the activity.

In 2014, the lunar conditions for viewing the Delta Aquariid maximum is extremely favorable. On July 30th (the predicted maximum date for this year) the moon will be a waxing crescent phase. It will set well before midnight allowing the prime morning viewing hours to be free of interfering moonlight. Moonlight will not encroach on viewing this activity until the second week of August, well past the time of maximum activity.

On the date of maximum activity the radiant for the Delta Aquariids lies at 22:42 -16. This position lies in southern Aquarius just a couple of degrees west of the 3rd magnitude star known as Skat (Delta Aquarii). This area of the sky rises in the east around 22:00 (10pm local daylight time). Serious observations should not begin until after midnight, allowing the radiant to gain sufficient altitude. The radiant lies on the meridian near 0300 LDT when it lies highest above the horizon. This is the best time to view the Delta Aquariids. As seen from latitude 40N the radiant will lie 34 degrees above the southern horizon. At this elevation above the horizon this will allow you to see slightly more than one-half of all the SDA activity. The other half of the SDA activity will occur beyond your line of sight. The best location to view the SDA activity is from latitude 16 S., where the radiant will pass directly overhead.

The Delta Aquariid meteors strike the atmosphere at a velocity of 26 miles per second (42km). This is an average velocity therefore few persistent trains are expected from these meteors. Unfortunately the SDA’s are not known for bright meteors and a majority of the activity is on the dim side. This fact, along with the low radiant altitude, makes it a challenge to view these meteors during the normally hazy July mornings.

A suggested strategy to view this activity would be to watch these meteors on or near the date of maximum activity from a rural site away from city lights. The best time lies between 0200 and 0400 local daylight time. Face southward with your field of view centered approximately one-half high in the sky. SDA meteors will shoot in all directions from the lower portion of your field of view. There will also be other weaker showers active at this time. Most notable will be the well known Perseids that will produce swift meteors entering your field of view from the upper left. The much slower Alpha Capricornids are also active with a radiant in the right portion of your field of view. Of course there will also be random activity with various velocities occurring at this time.

With the Perseids peaking near a full moon in August, the Delta Aquariids will offer the best opportunity to view meteor activity under favorable conditions this summer. Make an effort to see these meteors and be sure to let us know your results!

 
 

P209c

Possible Meteors from P/209 as seen at Maximum Activity from Mid-Northern American Latitudes

On the evening/morning of May 23/24, 2014, the possibility exists that a major meteor display may occur as seen from the North American longitudes of the northern hemisphere. On May 24, between the hours of 6:00 and 8:00 Universal Time, the Earth is expected to encounter numerous trails that were produced by comet P/209 LINEAR as it orbits the inner solar system. These trails were created as far back as 1798. The most recent trail expected to be encountered was produced in 1979. The center of the closest trail is expected to pass within 0.0002 AU (astronomical units) or roughly 18,500 miles from the Earth. This distance in more than 10 times closer than the mean distance from the Earth to the moon. Unfortunately this comet is a very small object and its dust production (as least recently) has been very low. Therefore a meteor storm is not expected, but rather a display on par with the major annual meteor showers for an unknown length of time is more likely. Major annual meteor showers normally produce near 60 meteors per hour as seen from dark rural locations. Although it is not known for certain, we can only hope that dust production was higher in the 18th and 19th centuries.

Some good news is that particles shed by this comet are expected to be larger than normal, therefore producing bright meteors. More good news is that the time of maximum occurs favorably for North America, ranging from 23:30 PDT to 2:30 EDT. The moon will be waning crescent phase and will not be a factor as it rises just before dawn.

These meteors will radiate from the northern portion of the constellation called Camelopardalis, approximately 10 degrees from Polaris (Alpha Ursae Minoris). This is a dim constellation that occupies a large portion of the high northern sky. From most areas of the northern hemisphere this constellation is circumpolar, meaning that it never sets below the horizon. As displayed on the illustration above, at the time of predicted maximum the expected radiant will have roughly the same altitude as the bright star Polaris, located only 10 degrees to the north. Therefore observers are urged to view northward at least between the hours of 6:00 and 8:00 UT on May 24th. This corresponds to 2-4am EDT and 11pm-1am PDT. The best locations to view this display will lie along the northern tier of states up to approximately 50 degrees north latitude. Locations further north will not be in total darkness as twilight will last all night long this time of year. Locations too far south (south of 30N) will see reduced activity due to the lower altitude of the radiant. One advantage for observers in the northern tropics is that many of these meteors may be “earthgrazers”, meteors that skim the upper atmosphere rather than penetrate lower into the more dense portions of the atmosphere. This creates meteors that are very long and sometimes last for several seconds rather than the normal sub-second duration. So while numbers may be lower as seen from the tropics, any activity seen from these regions may be more impressive.

May nights are not known for high meteor activity as seen from the northern hemisphere. In fact it is one of the least active times of the year with only 2-3 meteors normally being visible each hour during the evening. Morning hours are better with the addition of members of the annual Eta Aquariid meteor shower. Morning hourly rates are normally near 8 in late May. So any activity from comet P/209 should be fairly obvious. Unlike the well known Perseids of August, these meteors will strike the atmosphere at a medium velocity therefore persistent trains will be scarce. The average meteor from this display should last a bit longer (.5-1.0 sec.) on average compared to your average fast Perseid. This will help any observers who wish to try and photograph this display as the combination of bright and slower meteors should show up well on photographic exposures. These meteors may be seen in any portion of the sky but they will all trace back to the constellation of Camelopardalis. Other meteors not belonging to this display will have random directions and velocities. This display will only be visible from American longitudes as daylight will interfere from other areas. These meteors will be nearly invisible from the southern hemisphere as the radiant will lie on or below the northern horizon at the time of the predicted maximum activity.

This is the most favorable circumstance for a meteor outburst since the 2002 Leonids. Any data on this display is extremely important, even if no activity at all appears. Potential observers should provide precise times of observations, limiting magnitude, and other factors affecting your data. Be sure to share your observations with us so that we may forward it to those analyzing this data.1

1 Quanzhi Yand Paul A. Wiegert (2013), Will Comet 209P/LINEAR Generate the Next Meteor Storm?

Detailed Radiant Area

Detailed Radiant Area Looking Northward (the bright star Polaris lies near the “U” in Ursa Minor)

 
 

Examples of Perseid Meteors as seen from Latitude 35N near 4am

Examples of Perseid Meteors as seen from Latitude 35N near 4am

The Persesids are particles released from comet 109P/Swift–Tuttle during its numerous returns to the inner solar system. They are called Perseids since the radiant (the area of the sky where the meteors seem to originate) is located near the prominent constellation of Perseus the hero when at maximum activity. A great majority of these particles are tiny bits of rock and ice with the consistency of ash. They are only visible because of the tremendous velocity (38 miles/sec) as they strike the upper atmosphere. No Perseid meteor is known to have survived intact to the surface of the Earth as they are too fragile to survive their plunge through the atmosphere.

The Earth encounters Perseid meteors from July 13 through August 26 each year. Most of the Perseid activity is seen during the week centered on August 12. This is when the Earth passes closest to the orbit of the Perseid meteors. The greatest difference one year from the next is usually whether the moon is present while the Perseid radiant lies high in the sky during the early morning hours. If the moon is near full or a waning gibbous phase then the bright moonlight will obscure all but the brightest meteors. Most Perseid meteors are faint, therefore moonlight or local sources of terrestrial lights will greatly affect the number of meteor observed.

Luckily in 2013, at maximum activity on August 12, the moon will be a waxing crescent and will set near 2200 (10pm) local daylight time for locations at mid-northern latitudes. This will allow a good look at the show as the Perseid radiant is best placed high in the northeastern sky during the early morning hours

During the weekend of August 10/11, Perseid meteors will be visible near a rate of 20-40 per hour, depending on the time of night and your viewing conditions. On Monday morning August 12, the maximum rates should be near 60 per hour for observers under dark and transparent skies. If your skies are hazy then perhaps 40 per hour may be visible. If viewing from urban skies then expect to see no more than 20 Perseids per hour. By the morning of August 13, rates will have fallen by 50% to near 30 per hour. By the 14th rates will be near 15 per hour and again falling by near 50% each night.

While Perseid meteors can be seen all night long from most locations in the northern hemisphere, the radiant lies so low in the northern sky that only 3-5 meteors per hour are visible. If this is the only time you can watch it may be worth it as Perseids seen during the evening skim the upper atmosphere and are unusually long and long-lasting. If you can watch after midnight then I would suggest waiting until then as the Perseids will be far more numerous.

Perseid meteors can be seen in all parts of the sky. One can tell they are Perseids as their paths will all lead back to the constellation of Perseus. If it doesn’t then you have just witnessed one of the ten or so random (sporadic) meteors that are visible each hour during the morning hours. There are also minor showers active this time of the year from the constellations of Capricornus and Aquarius which will add a few meteors to the scene each hour. It would be best to view toward the darkest available direction. Do not look straight up, rather look halfway up in the sky to see the most meteor activity. The thickest slice of atmosphere lies near the horizon therefore looking straight up is looking through the thinnest slice and the least amount of activity. If one looks toward the horizon then too much of one’s field of view is wasted on the ground so the best compromise is looking half-way up.

For those located south of the equator, the Perseids are strictly a post midnight affair, as the radiant does not clear the horizon until the morning hours. For those located south of 35 degrees south latitude, the Perseids are not visible at all as the radiant never clears the northern horizon. So those situated near 30 degrees north latitude probably enjoy the best combination of high radiant altitude and long nights in which to enjoy the display.

The best Perseid activity, no matter the date or location, is usually seen during the last hour before the start of morning twilight, when Perseus lies highest above the horizon in a dark sky. This is usually between the hours of 0400 and 0500 local daylight time for most of us. While gazing high into the sky, one must be comfortable in order to avoid neck strains and fatigue. A folding lounge chair is the perfect solution. It is easily portable and comfortable. Be sure to also have a blanket or sleeping bag too, even if temperatures seem balmy. It’s surprising how the inactive body can become chilled even though the air temperatures seem warm.

The Earth is predicted to pass closest to the core of the Perseid meteors near 1900 Universal Time on August 12. This timing favors eastern Asia. The morning of August 12 will be the best time to see Perseid activity from North America. If that morning is cloudy the mornings of the 11th and 13th will also offer good activity.

The characteristic Perseid is a bright white or yellow meteor lasting less than a half second. The brighter meteors usually leave a persistent train or “smoke trail” that lasts a second or two after the meteor has vanished. This is not really smoke at all but rather ionized gas created by the meteor passing through the atmosphere at tremendous velocities.

One of the best times to try and photograph meteors is during the Perseid meteor shower. All you need is a camera capable of exposures lasting one minute or longer. Simply aim the camera high enough to clear the horizon and set the focus to infinity. Try to center the camera 30-60 degrees from the radiant so that the meteors are long enough to be easily seen on your photograph. Meteors appearing near the radiant will appear shorter as they are traveling in a direction toward you. It is also advisable to use the fastest film/ ISO setting possible to increase the sensitivity of you camera. Meteors will appear as straight streaks overlapping the curved trails created by the stars moving through the field of view. The length of the star trails will depend on the length of your exposure and the direction you point the camera. Pointing your camera northward will decrease the length of the star trails. Some photographers eliminate the stars trailing by mounting their cameras on motor driven mounts. With this setup the stars remain as pinpoints while meteors are obvious streaks.

While most folks are casual observers of meteor activity, it is also enjoyable and scientifically useful to record the meteor activity you see. Experts in meteor astronomy can reduce your data and compare it to others all over the world if you use certain standards in your reporting. First and foremost is to provide the accurate time of your observing session. It is helpful to time each meteor but not absolutely necessary as long as the start and finish times are provided. The observing conditions are very important to properly record, especially if your field of view is obscured by clouds or trees. These obscurations should be recorded to the nearest ten percent. Once per session is fine for trees but at least every 15 minutes for changing conditions such as cloudiness. The limiting magnitude of the sky in your field of view should also be recorded at least once an hour. The easiest way to do this is to count the number of stars visible in pre-selected areas of the sky. These areas and the resulting limiting magnitudes are available from the IMO web site at: http://www.imo.net/visual/major01.html#table2

It is also necessary to classify each meteor seen. On August 12, a majority of the meteors seen will be Perseids. There is no way that every meteor is a Perseid that night. As stated before. there are on average 10-15 random meteors occurring each hour. These can come from any direction and be of any velocity, usually slower than the Perseids. Perseids will always line up with the radiant in Perseus and will usually be swift unless they occur close to the radiant or close to the horizon.

Other parameters that can be recorded are the magnitudes of each meteor, the color, the velocity (slow, medium, fast) and whether the meteor produced a persistent train. If you do decide to record data, be sure to share it with us by emailing your data to: lunro.imo.usa@cox.net or using online forms available at: amsmeteors.org or imo.net. Note that one must be a registered online member of the AMS in order to post data to their site.

The Perseids will be the last time a major shower is visible under good conditions for 2013. All other major showers for the remainder of the year are spoiled by moonlight. Not until the Quadrantids of 2014 will a major shower be visible under favorable conditions. Also note that the 2014 Perseids will be spoiled by a full moon so not until August 2015 will one have another good view of Perseid ac

Examples of Perseid Meteors as seen from Latitude 25S near 5am

Examples of Perseid Meteors as seen from Latitude 25S near 5am

 
 

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 29 and May 20. The strongest activity may be 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 2013, the waning crescent moon will interfere on the weekend of May 4/5, but next week thinning moon will be less of a problem. 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 Aquarids, 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 Antihelion 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 ALPO Meteors Section. We accept data from observers with all levels of experience. We suggest sharing your observing sessions with us and also Meteorobs, the global meteor network for meteor observing.

We look forward to hearing from you!

Robert Lunsford

ALPO Meteors Section Coordinator

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

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

 
 

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 29 and May 20. The strongest activity may be 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 2013, the waning crescent moon will interfere on the weekend of May 4/5, but next week thinning moon will be less of a problem. 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 Aquarids, 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 Antihelion 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 ALPO Meteors Section. We accept data from observers with all levels of experience. We suggest sending your data to us and to Meteorobs, the global meteor network for meteor observing.

We look forward to hearing from you!

Robert Lunsford

ALPO Meteors Section Coordinator

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

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

 
 

Examples of Quadrantid meteors as seen looking north just before dawn from mid-northern latitudes

The Quadrantids are another obscure winter shower usually lost to cloudy weather or sub-freezing temperatures. If your sky is clear on the morning of January 3, 2013, you should check it out as the Quadrantids have the potential of being the strongest shower of the year. This display is active from January 1-10, but intense activity is limited to only six hours centered on the time of maximum activity. In 2013, the peak time is predicted to occur near 1300 Universal Time, which corresponds to 800am EDT and 500am PST on the morning of January 3rd, 2013. Unfortunately this timing is too late for most sites in North America as sunlight or morning twilight will interfere at this time for all but the western quarter of the USA, the western territories of Canada, and Alaska. If caught at maximum and viewed under rural skies, this display has the potential to produce in excess of 100 shower members per hour. Unfortunately, it is doubtful that these rates will be reached as a bright waning gibbous moon will be in the southern sky. If your sky is transparent it will still be possible to see good activity on the morning of the 3rd, no matter your location. Just be certain to watch as late as possible and to face toward the northern half of the sky with the moon at your back. Areas located in high northern latitudes also have the opportunity to view Quadrantid activity as soon as it becomes dark. This would avoid moonlight that interferes with morning observations this year. Favorable areas for such an attempt in 2013 would be Russia and Kazakhstan. For the rest of us, we will have to put up with moonlight and give it our best shot. This will be the last chance at decent meteor activity until the Lyrids peak in April.

 
 

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. 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 0800 Universal Time on December 22nd. This corresponds to 0300 EST and midnight PST. There also exists the possibility that another small display of activity may also occur earlier near 0300 UT, also on the 22nd. This corresponds to 2200 (10pm) EST and 1900 (7pm) PST on the evening of December 21st. Unfortunately the waxing gibbous moon will be in the sky during the evening hours and will obscure all but the brightest Ursids. Unless you are viewing from Europe, where the moon will have set by this time, it may be best to wait until after the moon has set on the morning of the 22nd to view Ursid activity. 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 faster 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 Saturday morning, 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 Thursday night/Friday morning December 13/14. Activity is currently low with only 1-2 meteors per hour appearing from this source. 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 2am LST, when the Geminid radiant will lie nearly overhead. At this time hourly rates should be near 20-30 for city viewers, 40-50 for suburban viewers, and 60-70 for rural viewers. 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.

After 2am LST the Geminid radiant will drift lower in the western sky. Rates will slowly fall as the radiant altitude decreases.

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 so do not wait until the weekend or you will be out of luck.

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.

Clear Skies!
Robert Lunsford
ALPO Meteors Section

 
 
<a href=”http://www.amsmeteors.org/wp-content/uploads/2012/04/LYR1.jpg”><img title=”Lyrids” src=”http://www.amsmeteors.org/wp-content/uploads/2012/04/LYR1-300×193.jpg” alt=”” width=”300″ height=”193″ /></a>

Examples of Lyrid activity seen on April 22, 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 21/22. Peak rates are predicted to occur near 6:00 Universal Time on April 22, which corresponds to 0200 EDT and 2300 PDT (on the 21<sup>st</sup>). 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 22nd.

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 new phase and invisible at night. Lunar conditions could not be any 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.

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