Major Meteor Showers in 2004
2003 was a difficult year for meteor observers, with moonlight impacting most of the major showers. 2004 promises to be different; in particular, the Perseids should be near their best for viewers in western North America. The Geminids, Lyrids and Leonids are also free from moonlight this year. Of course, moonlight interference is only one of the factors that determine the impressiveness of shower rates. Your local observing conditions (weather and light pollution) are perhaps the biggest factor. Expected rates in this article assume a dark-sky site. Also, most of the major showers show a distinct activity peak lasting less than half a day. If this peak occurs during the middle of your daytime hours, you may miss the best rates. While watching near the peak time is advisable, it's also important to note that the elevation of the shower's radiant plays a big role. If the radiant is lower than 30 degrees altitude, expect to see less than half the shower's Zenithal Hourly Rate, even if all other conditions are good. Finally, peak times and intensities are somewhat uncertain for all showers. Unexpected higher or lower activity occurs more often than you might think. I've included a couple of extreme examples in this year's synopsis: the June Bootids and Draconids are periodic showers that usually produce nothing, but might produce something in 2004.
To help you determine the most promising dates and times for meteor observing, here is a rundown of major meteor showers in 2004, with observing prospects for the Pacific Northwest (USA).
QUADRANTIDS (maximum January 4, 6h UT [ Jan. 3, 10:00pm PST])
The "Quads" are one of the strongest annual showers, with peak rates that rival the Perseids and Geminids. Unfortunately, the peak is very sharp and somewhat variable. Add usually poor weather prospects, and this shower is difficult to catch. This year's Quads peak at 10pm PST on January 3, when the radiant is near the horizon and a bright gibbous Moon hangs in the sky. A better time to watch will be after 3am on the morning of Sunday, January 4. The radiant will be satisfactorily high in the sky from then until the beginning of twilight, and the Moon will be sinking lower until it sets at around 5:30. Astronomical twilight begins after 6:00, and a watch can be extended for sometime thereafter until the sky really begins to brighten.
Expect 10-20 Quadrantids and 5-15 sporadic meteors per hour from the best sites.
The Lyrids are active from April 16-25, but only qualify as a major shower for about a day centered around their maximum. While the peak is predicted for the early evening of April 21, watches should probably begin around midnight when the Moon has set and the radiant is higher. Observers may be rewarded with 5-10 Lyrids and a similar number of sporadics each hour on the morning of Thursday, April 22.
I was able to observe the 2004 Lyrids on the morning of April 22. Report is now in my Online Observing Log.
Always a marginal target from mid-northern latitudes, the Eta Aquarids are complicated by a bright Moon this year. Die-hards who want to try to catch a couple of earthgrazing ETAs should watch near the beginning of morning twilight on one of the days around the nominal maximum of Wednesday, May 5.
JUNE BOOTIDS (maximum June 22/23???)
This periodic shower produced an outburst in 1998, and might again in 2004. Or, it might not. We'll just have to see. New dust trail models predict a possible maximum on Tuesday evening/Wednesday morning, June 22/23. If this prediction holds, the crescent Moon will interfere only slightly; the radiant is well above the horizon throughout the very short night.
I was able to observe the June Bootids on the morning of June 23; the shower was more active than usual, but my rates were only 5-7/hour. My experience was typical, but some observers at other longitudes saw significantly higher activity. My report is now in my Online Observing Log.
The South Delta Aquarids are barely a major shower from mid-northern latitudes, but are part of an impressive complex of activity in late July. Near their peak, the SDAs produce 5-10 meteors per hour. Several other radiants in the "Aquarid/Capricornid complex" are active at the same time and produce a handful of meteors per hour between them. Dark sites will also reveal 10-20 sporadic meteors per hour, as well as a few early Perseids. I usually see about 30 total meteors per hour during these morning sessions. This year, a waxing gibbous Moon will confine watches to the last couple of hours before morning twilight (roughly 2-4am) on the most productive mornings of July 27-29 (Tuesday, Wednesday, and Thursday mornings). This is fine, because these are the usually the best hours anyway.
I did a total of 5 hours on these three mornings. On July 27 and 28, the SDAs were at a normal observed rate of 5-7/hour. I only watched for one hour on July 29, and only saw 1 SDA. Hourly total meteor rates on these three mornings ranged from 21 to 28 meteors/hour.
PERSEIDS (maximum August 12, 11h UT [4am PDT])
The Perseids are, without a doubt, the most popular annual shower for NW observers. The often warm and clear weather, combined with the Perseids' reliably high rates and long shower duration, make this stream an ideal if non-representative introduction to meteor observing. This year, the observing prospects for the Pacific Northwest are probably at their best since 1997 with respect to both the Moon and the peak timing. Plan on an all-night session for the night of August 11/12 (Wednesday evening/Thursday morning), with highest rates during the last couple of hours before morning twilight on the 12th. The nights before and after the peak should be decent as well.
A few Perseids are visible starting in mid-July, when the radiant is far from Perseus (see radiant drift map). Moonlight interferes during early August as rates rise gradually. On August 11 a steep increase begins. This year, at least one activity model predicts that there could be an early peak during our midday hours on August 11. Europe will be best-placed to view this if it happens. In any case, you can start observing Perseids as soon as it gets dark on the evening of Wednesday, August 11 (10-10:30pm). Don't expect really high rates then, though, as the radiant is still low. 10-20 Perseids is a typical count for the first hour, but it should just keep getting better as the Thursday morning hours wear on. The radiant will be getting higher and the shower's intrinsic activity should be rising. The waning crescent Moon shouldn't be much of a bother from a dark site; under similar conditions in 1996, my last hour of observations produced 96 Perseids! While the peak strength is certainly variable, I have similarly high hopes for this year's display. Watches can be extended a bit into morning twilight until the sky is markedly brighter. Remember that you'll only see the best rates from a truly dark site; city and suburb dwellers can still see Perseids, but in nowhere near these numbers.
Perseids aren't the only meteors out there. Sporadic rates tend to be 10-15/hour, and even higher from really dark sites. The Aquarid complex still produces a few meteors, and the Kappa Cygnid radiant near the head of Draco is a minor source of slow and sometimes bright meteors.
If at all possible, make a trip to clear, dark skies this year for the Perseid maximum!
DRACONIDS (maximum October 8 [October 7 PDT; uncertain]) (radiant map)
The Draconids are absent more often than not, but have produced two major storms in 1933 and 1946, and several other significant outbursts. Recently, they have shown signs of becoming active on an annual basis, although this is not certain. 2004 will be a good year to watch for some activity, as the Moon will be a waning crescent. The best time to watch will be the evening hours of Thursday, October 7, unless a subsequent prediction suggests a better time. Draconids are very slow meteors; keep this in mind when trying to separate them from sporadics that accidentally line up with the radiant.
No unusual Draconid activity was reported in 2004, just the usual few possible shower members.
The Orionids produce rates of 5-15/hour for a week in mid-October, with occasional surges in activity that may reach 25 or even 50/hour. The shower's radiant near Betelgeuse is best-placed just before morning twilight begins. This year, the waxing Moon will be out of the way for most of the interesting period between October 18 and October 25. Only on the last couple of nights does the Moon start to interfere. I generally start Orionid watches at about 1 or 2am PDT. The Orionid activity is quite variable; both exciting and disappointing watches are possible. Watch for slow meteors with radiants near the head of Cetus; these are early members of the Taurid stream.
Orionids seem to have performed normally in 2004, with maximum hourly rates in the 20s. I only got out for one hour due to poor weather.
Strong outbursts of Leonid activity from 1998-2002. In 2003, several smaller outbursts were predicted. At least two of these did in fact occur, with peak ZHRs of about 20 and 70. For 2004, predictions center around November 19. Jeremie Vaubaillon and others say the Earth will encounter the outer portions of a debris trail around 21:49 UT on November 19, with a potential Zenithal Hourly Rate of ~65. Unfortunately, this is during the daylight hours for the continental US. A smaller peak (ZHR~10) that may include some bright fireballs is possible earlier on the 19th, predicted at around 6:40 UT. The eastern US would be in a position to observe around this time (1:40am EST).
A subsequent prediction finds another possible peak of >50/hour on November 8 around 23:30 UT (3:30pm PST, another miss for North America). The Leonid radiant should be noticeably further west during such an early encounter, if in fact it does produce any activity. For details on the above predictions, see
The Leonids have an annual "background" activity with a broad peak of 10-20 meteors/hour, and sporadic activity is generally good as well. A few leftover Taurids also appear from radiants near the Pleiades and Hyades. Any morning between November 16-20 would be a good bet to watch for Leonids. Unless exceptional activity is predicted, Leonid watches should start at about 2am and continue until morning twilight, as the radiant is at a satisfactory altitude during these hours. Luckily, the Moon won't interfere at all this year (OK, slightly as a waning crescent for the November 8 prediction).
It appears that no noticeable Leonid activity was observed on November 8. On November 17, I watched for two hours before morning twilight and saw rather weak but bright Leonid activity (9 per hour, average magnitude 1.6). November 18 was foggy, but November 19 provided nice rates for me (and for many other observers). In 2.5 hours, I saw 43 Leonids, with 30 of these coming in the last half of the session. Interestingly, no enhanced activity was noted by European and Asian observers around the predicted 21:49 UT. On the morning of November 20, my casual 30-minute watch yielded 6 Leonids and 6 sporadics.
The Geminids are possibly the most reliable of the annual showers. While the shower's overall duration is much shorter than that of the Perseids, there is a definite plateau of maximum activity. Therefore, even though this year's maximum occurs during daylight, the Geminids should still put on a strong display for the Pacific Northwest. The predawn hours of Monday, the 13th will showcase the radiant high in the sky, while the rates start to ramp up to maximum. 50-75 Geminids/hour are likely, plus 10-20 sporadics. On the evening of Monday, the 13th, rates should still be near their maximum value. At the end of evening twilight, the radiant lies near the horizon and rates will be fairly low (although a handful of earthgrazers may be seen). By 8pm PST, the radiant is at a decent altitude. Geminid rates should be at about 50/hour; it will be interesting to see how long high rates last before beginning their usual steep decline. 2001 data from the IMO, and my 2003 observations, show the ZHR down to about 40 by 1:00am on the 14th (solar longitude equivalents used). In some earlier years, rates were still >70 at this time. This year's Geminids rival the Perseids as a show not to be missed; the Moon is a thin waxing crescent and won't interfere with the prime viewing hours.
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These are the best meteor observing opportunities in the year 2004, and represent the showers that will be most appealing to novice and intermediate observers. Of course, there is meteor activity every night of the year. Sporadic rates are low from mid-winter through June. In July, rates of random and minor-shower meteors pick up, and are high through the remainder of the year. For more information on meteor observing, check out the links below.
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