Major Meteor Showers in 2011
In 2010, the Perseids and Geminids put on nice shows under mostly moon-free skies. The Orionids had quite a bit of moonlight interference, but rates seemed to be high for the fifth straight year. The Lyrids and Leonids also had a bit of a moon problem, and no unusual activity was reported. The other major showers were so badly moonlit as to be nearly unobservable.
2011 is even worse as far as moonlight is concerned. The only showers that are moon-free are the Quadrantids (good luck with getting clear skies), the Eta Aquarids (marginal except for southern observers), and the South Delta Aquarids (more of a "mid-major" shower). The Perseid peak contends with a Full Moon, and the Geminids have an 85% illuminated waning gibbous moon. The moon is at least bothersome for all of the other showers.
There have been some interesting predictions of enhanced meteor activity for several showers in 2011. The Draconids or Giacobinids are a periodic shower that has produced storms in the past. Several models predict ZHRs of several hundred per hour near 20h UT on October 8. Unfortunately, this is during the middle of the day in North America. If you happen to live where it's nighttime--guess what? The moon is 90% illuminated and will wash out a majority of the meteors.
According to the IMO Meteor Shower Calendar, work by Jeremie Vaubaillon predicts an outburst of the periodic Epsilon Eridanid shower at 19:34 UT on September 12. Once again, this will occur during daylight hours for North America (and there's a Full Moon)!
There is always the possibility of unusual Leonid activity, but this shower also deals with a waning gibbous moon in 2011.
Basic Meteor Observing Information:
Don't forget to consider the effect of radiant elevation when planning an observing session. Even if a shower is near its activity peak, you won't see a thing from it if the radiant is below your local horizon. In the case of a strong shower, you may expect a (very) few long "earthgrazing" meteors when the radiant is near the horizon, but even when the radiant has reached an elevation of 30 degrees you will only see half as many meteors as you would if it were at your local zenith. Most shower radiants are highest during local morning hours, often just before twilight begins. That's usually when you want to observe, although occasionally a rising Moon or a sharp activity peak will suggest an earlier time. See "WHEN TO WATCH" below.
I get quite a few questions about "when to watch" and "where to look". "Where to look" is usually fairly easy: center your field of view high in the darkest, least-obstructed part of your sky. If you have tall trees or an overpowering city light dome in one direction, you probably should face another direction. You don't have to look right at the shower's radiant. Indeed, you'll probably see fewer meteors if you do. But it's also nice and productive to keep the radiant somewhere within the field of view. If there's a bright Moon in the sky, keep it out of your field of view or try to block it with something, like a tree or a car or a chair...
WHEN TO WATCH:
For each shower, I list the shower's name and a "Predicted Maximum". This is when THE SHOWER should be at its maximum activity, whether or not you are in a position to view it. If this maximum time happens to coincide with a time when it's clear and dark and the radiant is high in your sky, you'll probably be a happy camper. However, life usually involves compromises. So, for each shower I've included a paragraph titled "WHEN TO WATCH". This is my take on the best viewing window for each shower. These times are generally valid for all of North America and are given as local time (i.e., you don't have to worry about converting for your time zone). It may be worth looking up the beginning of astronomical twilight for your location on a given date (in an almanac or planetarium program); this will give you an idea of how late you may observe into the prime morning hours.
Disclaimer: Vagaries of meteor activity, your personal ability to perceive meteors, and local sky conditions all have a dramatic effect on the rates you observe. Sky conditions to consider include weather and light pollution. If you can't see the summer Milky Way in Cygnus on a moonless night when this region of the sky is overhead, you probably won't see much from even the strongest annual showers. Clear, dark skies are essential for satisfactory meteor observations. More shower meteors are visible from a dark site, and sporadic (random) meteor rates are enhanced greatly.
QUADRANTIDS
Predicted Maximum: January 4, ~1h UT (= Jan. 3, 5pm PST; = Jan. 3, 8pm EST)
Moon: New Moon (no interference)
WHEN TO WATCH: European and Asian observers should have the best view of this year's Quadrantids, and should focus on the morning of Tuesday, January 4. North American observers will get lower rates, but both the mornings of January 3 and January 4 will produce some activity. Observe during the last couple of hours before twilight on Monday, January 3 (better for West Coast observers) and from about 1am until morning twilight on Tuesday, January 4 (better for East Coast observers). Be aware that these are more of a best guess; the Quadrantids are not very predictable.
The peak of this shower doesn't last long, and is notoriously variable in strength and timing and duration. The 2009 peak was much longer and stronger than the one in 2008. North American observers with clear skies could see anywhere from 15 to 60 Quadrantids per hour during the windows above. The Quadrantid radiant is highest in the predawn hours. From latitudes above 41N, the radiant is circumpolar (above the horizon all the time), but it is very low during the pre-midnight hours. It is possible to see a few earthgrazing Quadrantids in the evening--a challenge for adventurous observers in the Pacific Northwest this year. An even bigger challenge is the January weather, which is usually awful.
Quadrantids are medium-velocity meteors, and some bright ones are often visible around the time of maximum activity. The radiant is in a rather blank area surrounded by the constellation figures of Bootes, Hercules, Draco and Ursa Major (see the radiant map). Along with the Quadrantids, there are usually quite a few sporadic meteors visible from dark sites.
Note: Skies were cloudy on the morning of the 4th. I did get out for 1.5 hours on the morning of January 3rd and saw 26 Quadrantids and 22 other meteors.
LYRIDS
Predicted Maximum: April 22, ~23h UT (= Apr. 22, 4pm PDT; = Apr, 22, 7pm EDT)
Moon: Waning Gibbous (major interference)
WHEN TO WATCH: Observers in mid-northern latitudes get a brief period when the radiant is above 30 degrees and the moon has not yet risen. For my location in Southern Oregon, this is between about midnight and 1:30am on the morning of Saturday, April 23. Check your local moonrise time; the window gets shorter the farther south you go. Expect between 5 and 15 Lyrids per hour from a dark site, plus a few other meteors.
The Lyrids are another shower with a reputation for variable rates and timing. Usually, they produce about 20 meteors per hour at maximum (under dark skies). Lyrids produce fairly fast meteors with a reputation for being faint on average. However, I've seen my share of Lyrid fireballs, and the 2009 display was uncharacteristically bright.
ETA AQUARIDS
Predicted Maximum: May 6 (broad)
Moon: Waxing Crescent (no interference)
WHEN TO WATCH: The Eta Aquarids have a fairly broad peak. The morning of Friday, May 6 would be the nominal maximum, but if that's clouded out try the adjacent mornings. With no moon, this is a good year to observe this challenging shower.
The Eta Aquarids are better for Southern Hemisphere observers, but are a bit difficult for everyone. The key is to watch during the last hour or so before twilight gets really bright. In terms of local time this depends on your latitude and also on your longitude with respect to the center of your time zone. Check an almanac or planetarium software. At latitude 42.6 degrees North, I've had my best results from about 3:40-4:40am local daylight time.
The Eta Aquarids would produce maximum rates of >50 per hour if we could see them with the radiant high in a dark sky. In the northern temperate latitudes, we don't get close to that. We get just a small taste of them in an intricate dance just before dawn. At 40 degrees North, the radiant is only about 15 degrees up when twilight begins. If I could get those conditions for an hour, I might see 10-15 ETAs. However, everything's changing. Before that time, there are fewer shower members visible because the radiant is lower. After that time, the radiant is higher and rates would keep rising but for the onrush of twilight. You're fortunate indeed if you see 10 ETAs in an hour, along with about 5 sporadic (random) meteors.
The low radiant elevation means that the earliest ETAs you see will be "earthgrazers": long, relatively slow and often tracing paths along the horizon. Bright earthgrazers are spectacular. Unfortunately, because of their greater distance from the observer, earthgrazers tend to be faint. As the radiant gets a bit higher, the ETAs take on more of their typical appearance: fast meteors, bright on average and often leaving a glowing train. You'll only catch a few of them, though, because dawn is approaching. This shower seems to fluctuate irregularly, and you could easily hit either a spurt or a lull during the all-too-brief observing windows.
SOUTH DELTA AQUARIDS
Predicted Maximum: July 28 (broad)
Moon: Waning Crescent (minor interference)
WHEN TO WATCH: This shower's maximum seems to be broad and irregular. Watch during the last couple of hours before morning twilight on Thursday, July 28, or try the adjacent mornings. Remember that twilight comes pretty early for mid-northern latitudes at this time of year (around 4am for my place).
The South Delta Aquarids are barely a major shower from 40 degrees N; southern observers have a somewhat better view, but the maximum ZHR is probably about 20. The real treat is the number of meteors from different sources visible from dark sites on moonless mornings in late July. Along with 5-10 South Delta Aquarids, a mid-northern observer might see at least the same number of sporadic (random) meteors. There will probably also be a couple of meteors from the Antihelion and Alpha Capricornid radiants. The Perseids are just becoming active, and you may see 2 or 3 per hour. This can add up to an impressive number of meteors with a bit of luck. You may not be able to assign every meteor to its correct radiant, but that doesn't keep you from enjoying them! South Delta Aquarids are medium-speed meteors, and tend to be faint on average.
Note: In a 1.5-hour session on the morning of July 27th, I only saw 6 SDAs along with 22 sporadics, 2 Perseids, and 3 members of other showers.
PERSEIDS
Predicted Maximum: August 13, ~6h UT (=August 12, 11pm PDT; =August 13, 2am EDT)
Moon: Full Moon (major interference)
WHEN TO WATCH: The Perseids have a severe moonlight problem this year. The Full Moon will be in the sky all night long, and will wipe out most of the meteors. If you can get high and dry (clean, dry air will scatter less moonlight), you might see as many as 15-30 Perseids per hour on the morning of Saturday, August 13 from midnight until morning twilight. Face away from the moon and keep it out of your field of view for best results.
The Perseids are probably the most-watched annual meteor shower. The shower has a very long duration, from about July 15 through August 25, but is most interesting around its peak on August 13. In recent years, the exact timing of the peak has varied somewhat from the predictions.
The Perseid radiant is above the horizon the entire night for observers north of latitude 32N, but it is fairly low at the end of evening twilight. Rates are better in the morning. Perseids are fast meteors and tend to be fairly bright on average. An occasional fireball is seen. The Perseids aren't the only meteors around: sporadics, minor showers like the Kappa Cygnids, and a few leftover South Delta Aquarids add to the display but will be hard to see due to moonlight in 2011.
Note: I observed Perseids after moonset on August 10 (27 Perseids and 26 other meteors in 1.75 hours) and under full moonlight on August 13 (51 Perseids and 9 other meteors in 2.2 hours). Details are in my observing log.
DRACONIDS (aka Giacobinids)
Predicted Maximum: October 8, 20h UT? (=October 8, 1pm PDT; =October 8, 4pm EDT)
Moon: Waxing Gibbous (major interference)
The Draconids are a periodic shower that produced storms of thousands of meteors per hour in 1933 and 1946. During most years, few or no Draconids are seen, but when the Earth crosses a denser trail of dust left by parent comet 21P/Giacobini-Zinner things get interesting. 2011 should be one of those interesting years, with models suggesting a peak within a few hours either side of 20h UT on October 8. As mentioned above, this is daylight for North America. Rates are very uncertain, but given the shower's stormy history it could be worth watching despite the bright moonlight.
WHEN TO WATCH: If you're in Europe, watch on the evening of Saturday, October 8. If you're in North America, don't expect much (if anything), but watch on the evening of Saturday, October 8. While previous storms have been brief, East Coast observers may have the best chance of seeing something soon after it gets dark. The Draconid radiant is highest in the early evening, and gets very low in the morning hours.
Draconids are notable for being very slow-moving meteors. They are likely to be faint, which means that even favored observing locations may not see much in the moonlight.
ORIONIDS
Predicted Maximum: October 21-24 (broad and irregular)
Moon: Waning Crescent (moderate interference)
WHEN TO WATCH: The moon causes fewer problems later in the activity period this year. From mid-northern latitudes, the Orionid radiant reaches 30 degrees elevation at around 1am. The 36% illuminated moon rises soon after on the morning of the 21st, but then rises later and gets fainter as the week goes on. Even when the moon is in the sky, Orionid observing should be rewarding from otherwise dark sites. You might even explore which conditions yield the most Orionids: early in the morning when the moon is down but the radiant is low, or later in the morning when the radiant is high but the moon is in the sky? All mornings between October 21 and October 24 would be suitable for this experiment. For casual observers, I suggest the mornings of Saturday, October 22 and Sunday, October 23, from 1am until morning twilight.
The Orionids are capable of producing interesting activity from October 17-25. Traditionally, the shower produced maximum rates of about 25 per hour, with occasional enhancements to 50 per hour occurring irregularly. Recently, the shower has been stronger. Very high rates were seen on several mornings in 2006. The last three years have produced a broad maximum of 35-40 per hour, stretching from October 20-24.
The Orionids are fast meteors, perhaps a bit faint on average but capable of producing fireballs. Note that the radiant is north of Betelgeuse and not right in the middle of Orion. A minor shower called the Epsilon Geminids has a nearby radiant that can cause confusion, but usually produces only 1-2 meteors per hour. The South Taurids produce a few nice, slow meteors from a radiant farther west. Finally, 5-15 sporadic meteors are usually visible each hour under dark sites.
Note: I observed the Orionids for 1.4 hours on the morning of October 22nd and experienced very low activity with only 16 Orionids and 6 other meteors. The morning of the 23rd was somewhat better--I observed for 2.5 hours and saw 47 Orionids and 29 other meteors.
LEONIDS
Predicted Maximum: November 18?
Moon: Last Quarter (major interference)
Who knows what to expect from the Leonids? The IMO Meteor Shower Calendar summarizes some of the predictions, including a possible strong outburst of faint meteors on November 16 that favors Eastern Europe and parts of Asia. The moon will be brighter on the 16th, and then nearer the radiant on the 17th and 18th, so it's not an especially good year to observe this shower.
WHEN TO WATCH: The Leonids are best observed from about 2am until the beginning of morning twilight. Try the mornings of Thursday, November 17 and/or Friday, November 18. If the timing of 22:36UT is correct for the November 16 outburst, it will happen many hours before the radiant rises in North America. I wouldn't expect more than 5-10 Leonids per hour even under favorable conditions.
The Leonids are very fast meteors. The shower is active at a low "background" level for about a week from November 14-21.
GEMINIDS
Predicted Maximum: December 14, ~17h UT (=Dec. 14, 9am PST; =Dec. 14, 12noon EST)
Moon: Waning Gibbous (major interference)
This isn't a very good year for the Geminids. For mid-northern latitudes, the bright moon rises at around 8pm on the evening of the 13th while the radiant is still low, and will be in the sky all night long. There is an additional hour of moon-free evening time on the 14th, but note that Geminid rates usually drop off quickly after the peak. If you choose to watch while the moon is in the sky, either face away from the moon or make sure you block it with something to keep the direct light out of your eyes. The Geminids produce some bright meteors, so quite a few will be visible despite the moonlight if your skies are otherwise clear and transparent.
WHEN TO WATCH: Late Tuesday evening, December 13 through morning twilight on Wednesday, December 14. Also Wednesday evening, December 14, around 8-9pm local standard time.
The Geminids show a broad peak. When moonlight doesn't interfere, peak rates may exceed 100/hour from dark northern hemisphere sites, and rates of 60/hour may persist for 24 hours or more. Southern hemisphere observers also enjoy this shower, although with lower rates and a shorter viewing period in the predawn hours. The radiant is highest in the sky at around 2am.
Geminids are medium-speed meteors. Most of them don't leave glowing trains, but the brighter ones are often colored (yellow, green and blue are most common). The Geminids seem to produce quite a few fireballs. Often, more bright meteors are seen during and after the maximum than before the maximum. A good number of sporadic and minor-shower meteors add to the show.
Note: I did a brief, casual watch on the evening of the 13th before the moon rose and saw about a dozen Geminids in an hour. On the morning of the 14th, I started counting at 3:40am under bright moonlight. Skies were perfectly clear when I started, but there was a brief period during my watch when clouds moved in and covered as much as half the sky. After the clouds departed, there was still some high haze. In spite of all this, the Geminids put on a good show. I saw 70 Geminids and 7 sporadics in 1.82 hours of observing time. The mean Geminid magnitude was +1.2, and I didn't see any fireballs but saw a good number of -1 and -2 Geminids.
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Other Sources of Meteor Activity
The major showers listed here (except the Draconids) are fairly reliable and occur every year. However, meteor activity is visible on any clear night. Random sporadic meteors, minor showers, and major showers near the beginning or end of their activity period all contribute to this "background". For the Northern Hemisphere, there is a general pattern of lower rates during the first half of the year and higher rates during the second half, but rates vary greatly from hour to hour, day to day, and observer to observer. Occasionally, unexpected high activity occurs. It is up to the observer to objectively describe what was seen. In many cases, high activity may be ascribed to randomness. At other times, many of the meteors seen may be part of a periodic or previously unknown shower.
There are some periodic, irregular, and hypothetical showers that could produce surprises during 2011. The meteorobs mailing list is a good way to keep track of predictions and developments "beyond the majors".
Other Meteor Shower Info.
Outside Links
General shower attributes, radiant maps and predicted times of maximum are adapted from the International Meteor Organization's 2011 Meteor Shower Calendar as well as personal data. Recent activity profiles were characterized from http://www.imo.net/zhr. All on-site text and contents are Copyright 2010, 2011 by Wes Stone and may be reproduced for not-for-profit use so long as credit is given.
