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

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

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 3^rd, 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 3^rd, 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 22^nd. 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 22^nd. This corresponds to 2200 (10pm) EST and 1900 (7pm) PST on the evening of December 21^st. 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 22^nd 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 22^nd. 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

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^st). 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.

This illustration depicts Quadrantid meteors as seen from near 40 degrees north latitude during the last hour before the start of morning twilight on January 4, 2012.

This timing favors North America with local peak times ranging from 02:30am EST on January 4th to 11:30 PST on January 3^rd. The eastern half of North America will be more favorable as the radiant will lie higher in the sky at the time of maximum activity.

The Quadrantids are active from January 1^st through the 10^th but a great majority of their activity is produced during a six hour window on the morning of maximum activity. The radiant for the Quadrantids is located at 15:18 +50. This portion of the sky is located in a sparse area of northern Bootes between the stars Iota Draconis and Beta Bootis. The radiant is circumpolar for locations north of latitude 50N and briefly sets below the northern horizon for locations further south in mid-northern latitudes. The radiant is best placed during the last dark hour before dawn when it lies highest above the horizon in a dark sky. Far northern locations have a small window of opportunity to see Quadrantids just as evening twilight ends. The radiant will then be located low in the northwestern sky. Unfortunately the waxing gibbous moon will interfere this year with any attempts to view activity during the evening hours. The radiant reaches its lowest point near 1900 local standard time and then begins its slow ascent into the northeastern sky as the night progresses.

On the morning of January 4th, the 77% illuminated moon will set between 02:00 and 03:00, depending on your latitude. This coincides with the predicted time of maximum activity in the Eastern Time zone. The moon will be above the horizon for other time zones to the west. Still, the low altitude of the moon and the fact that it lies in the opposite portion of the sky will allow good views of any Quadrantid activity. If the moon is above your horizon be certain to view with it to your back to allow you to face the darkest sky possible.

Maximum rates for this shower are difficult to predict. Most observers across North America can expect to see a maximum of 40 Quadrantids per hour on the morning of January 4^th. If you are lucky it could be several times higher.

A good observing strategy for observers in North America would be to begin observations near midnight. This will allow eastern observers to catch the maximum should it arrive a bit early. Pacific observers may want to start around 2300 (11pm) on the 3^rd. While rates would most likely be low for western observers, any Quadrantid activity would be in the form of earthgrazing meteors, which are long-lasting as produce long trails as they graze the upper atmosphere. Face anywhere in the north to east quadrant, with your field of view half way up in the sky. This will keep the moon at your back. Quadrantid meteors will shoot upward from the northeastern horizon until it gains sufficient when it can produce meteor shooting in all directions.

Observers located in the northern hemisphere other than North American can expect to see approximately 25 Quadrantids per hour between moon set and dawn. Due to the high northern declination (celestial latitude) of the Quadrantid radiant, observers in the southern hemisphere will see very few Quadrantids. As seen from the southern hemisphere the Quadrantid radiant lies low in the north, if it clears the horizon at all before dawn.

This shower is named for the obsolete constellation Quadrans Muralis (Murals Quadrant), which once occupied the area of northern Bootes. Some meteor organizations refer to this shower as the Bootids. It is thought that this shower is related to the recently discovered asteroid 2003 EH1. Peter Jenniskens, who discovered this relationship, states that this object is most likely an extinct comet nucleus that appears to be the remnant of a larger object that broke up about 500 years ago. The Earth intersects the orbit of this object near January 3rd each year. The Earth intersects this orbit at a perpendicular angle, which means we quickly move through any debris produced by this object.

Don’t waste this opportunity to view this elusive shower. The Quadrantids of 2013 will peak with a last quarter moon in the sky. Maximum activity will also occur after daybreak for most of North American so should your skies be clear, do not waste this opportunity to view this shower.

Examples of Ursid Meteors

The Ursids are an obscure shower that is active for a week prior to Christmas. This shower is listed among the annual major showers as its ZHR (Zenith Hourly Rate) averages ten shower members per hour. Actual rates can be quite variable. I have seen years when it has reached 25 per hour and others when the shower is nearly non-existent. 2011 is a favorable year to try and view them as the waning crescent moon will not interfere much with observations.

The Ursids are particles shed from comet 8P/Tuttle. The Earth passes through the debris field of comet 8P Tuttle from December 18 through the 24th. We are situated closest to the center of the comet’s orbit on December 23rd; therefore the Ursids will be most active on this date. Particles from comet 8P/Tuttle strike the Earth at a perpendicular angle far above (north) the ecliptic. As seen from the Earth’s surface these meteors will appear to shoot forth from an area of the sky (the radiant) located near the bowl of the “Little Dipper”, also known as the constellation of Ursa Minor. The bright orange star Kochab (Beta Ursae Minoris) is a good guide to the Ursid radiant. Kochab is a circumpolar (never sets) star for all locations north of latitude 15 north. Therefore from this portion of the Earth, the radiant is in the sky all night long and Ursid activity may be seen at any time of night. For northern tropical areas the radiant is located low in the north during the evening hours. During the morning hours the radiant slowly rises and reaches the same altitude of nearby Polaris (Alpha Ursae Minoris) near 0300 local standard time. The best time to view Ursid activity from anywhere is during the last hour before dawn when the radiant lies highest above the horizon in a dark sky. Due to the high northern declination (celestial latitude), this shower is not visible to observers located south of the equator.

Since the Ursids strike the Earth at a perpendicular angle they will appear to travel slower than the better known Perseids of August or Leonids of November. Entering the atmosphere at 33 kilometers per second, this shower has velocities comparable to the recent Geminid shower.  Most of the Ursid meteors are faint therefore it is important to observe from rural areas away from city lights. Since the radiant lies in the northern half of the sky it would be best to face this general direction to see the most activity. There is no need to stare directly at the radiant, rather it is advised simply to place the radiant somewhere within your field of view so that it will to easy to trace which meteors line up with Kochab (Ursids) and those that don’t (non-Ursids or sporadics). There are two other areas of minor activity active during the Ursids. The antihelion radiant lies in central Gemini and will produce 2-3 slow meteors per hour. While facing north these meteors would enter your field of view from the upper right during the evening hours, from above and behind you near midnight, and from the upper left during the morning hours. The December Leonis Minorid radiant will produce swift meteors from eastern Leo Minor that are only seen from the northeast during the morning hours. If viewing from dark skies one should also be able to count 10-15 sporadic (random) meteors per hour.

If you would like to contribute more to our knowledge of the Ursids, then I invite you to get serious about meteor observing and to make an hourly count of the activity you witness. 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 AMS. We accept data from observers with all levels of experience.

These are examples of Delta Aquariid activity as seen facing south at latitude 40N near 0300 local daylight time on July 30.

The Delta Aquariids (SDA’s) are the strongest southern shower active during the northern hemisphere’s summer months. The Earth encounters these particles from July 21 through August 23 with a broad maximum occurring near July 30. Zenith hourly rates (ZHR’s) average 20 near maximum activity. During July and August this radiant is well placed as it rises near 2200 local daylight time and culminates at 0300 LDT. This shower is visible over most of the Earth but those observers located in the southern tropical areas are best suited as the radiant passes through their zenith. Observers further south may have a lesser zenith angle but they also enjoy a longer night which allows longer observation of this activity.

On July 30, the radiant is located at 22:42 (340) -16. The area of the sky is located in southern Aquarius, three degrees west of the 3rd magnitude star Delta Aquarii. An easier signpost may be the bright first magnitude star Fomalhaut (Alpha Pisces Austrinis), which lies fifteen degrees to the southeast of the SDA radiant. These meteors strike the Earth’s atmosphere with a velocity of 42 kilometers per second. Visually these meteors would appear to possess a medium speed for those shower members seen far from the radiant and high in the sky. Those seen close to the radiant or close to the horizon would appear to move slower. Most members of this shower are faint so rates seen from urban locations would most likely be unimpressive. Only from darker rural locations can this shower really be appreciated.

To view this shower it is advised that you limit your session to the morning hours when the radiant has achieved sufficient altitude. The best rates will occur near 0300 LDT when the radiant lies highest in the sky. You should face toward the southern half of the sky so that you may be able to better distinguish the SDA’s from the other weaker radiants active in this same general portion of the sky. Facing this direction will also allow you to experience the swift Perseids shooting into your field of view from behind. Although not as numerous as the SDA’s in July, the Perseids will provide some memorable bright meteors as you patiently wait for the fainter Aquariids to appear. In late July the moon will be a thin crescent phase and will not interfere with viewing the SDA’s.

While the Perseids provide more activity, their rates will be tempered by a bright moon in August. The Southern Delta Aquariids will provide a good show in impressive dark skies so make it a point to try to view this activity. If you are unable to view on the morning of the 30th, rates will still be good for a few nights before and after this date. Be sure to share your observations with the ALPO Meteors Section!

Examples of Eta Aquariid Meteors as seen from 40N latitude on May 7 near 4:00am LDT

Since the 2011 Lyrids were badly affected by moonlight, the next major meteor shower occurring under favorable conditions are the Eta Aquariids. The Eta Aquariids (ETA) 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 active between April 28 and May 21. 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.

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.

Examples of Eta Aquariid Meteors as seen from 25S latitude on May 7 near 5:00am LST

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 2011, the waxing crescent moon will not interfere at all with viewing this display. 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 Lyrids, then I invite you to get serious about meteor observing and to make an hourly count of the activity you witness. 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. We accept data from observers with all levels of experience. The easiest way to send in observations is to email your data to our operations manager Robert Lunsford. We look forward to hearing from you!