Major Meteor Showers in 2003
Part of Astronomy for the People, by Wes Stone

The year 2002 saw the Moon cooperate during the Perseids and the Geminids.  Other major showers were badly affected by moonlight, but lucky observers at cloud-free sites got to see a Leonid storm for the second year in a row.  This year, both the Perseids and the Geminids will struggle to compete with the bright Moon.  The true Leonid storms appear to be over, although several possible outbursts of tens to hundreds of meteors/hour are possible.  The Moon will be a varying hindrance for Leonid observers this year as well.  The Quadrantids are free from lunar interference, but the timing of this typically sharp peak is poor for US observers.  The Lyrids, Eta Aquarids, South Delta Aquarids and Orionids should perform decently this year.  A couple of the other annual showers offer marginal prospects for interested observers.  Here is a rundown of major meteor showers in 2003, with observing prospects for the Pacific Northwest (USA).

QUADRANTIDS (maximum January 4, 0h UT [ Jan. 3, 4:00pm PDT])
(radiant drift map)

The 2002 Quadrantids are favored by a nearly new Moon.  Unfortunately for US observers, the peak time of this short-lived shower is far from optimal.  The Quadrantid radiant skims the northern horizon during the evening hours, so observers in northern North America should be alert for earthgrazers after dusk on January 3.  Rates will probably be low, however, and decrease to near-zero below latitude 40 degrees North.  Observers should also monitor the morning hours on both January 3 and January 4, from 2am until morning twilight, but should expect low rates (~10/hour).  However, the timing, strength and width of the Quadrantid maximum seems to be variable, so there is the potential for a surprise.  Sporadic rates at this time of the year should be 10-15/hour from a dark site, and will further enhance the show.

LYRIDS (maximum April 22, ~22hUT [3:30am PDT])    (radiant drift map)

The Lyrids are active from April 16-25, but only qualify as a major shower for about a day centered around their maximum.  This year's maximum will occur during daylight for West Coast observers, although the exact time of the peak is variable.  Observers may be rewarded with about 10 meteors/hour on the morning of April 22 and/or the late evening/morning of April 22/23.  The nearly Last Quarter Moon will rise after 3am on the morning of the 22nd, which should provide a good interval of darkness. 

The radiant is highest just before twilight, and activity should be rising, so observers may want to continue watching even after moonrise on April 22nd.  Normally, the Lyrids produce a peak ZHR of about 20.  Occasionally, outbursts of up to 100/hour have been observed, but there is currently no way to predict these unusual events.

ETA AQUARIDS (maximum May 6 [broad])     (radiant drift map)

This shower strongly favors the Southern Hemisphere, and although maximum ZHRs usually exceed 40, observers as far north as 45N would be lucky to see 10 meteors/hour from this shower.  At least there is no lunar interference this year.  Because the radiant rises late in the morning, and attains an altitude of only 13 degrees by the beginning of morning twilight (~4:00am), visibility is brief on any single morning.  However, the maximum tends to be broad and irregular, with ZHRs >30 from May 3-10.  In 2002, I observed the Eta Aquarids on two mornings and had my best success between 4:00 and 4:40am even with the encroaching twilight.  I would suggest beginning viewing a bit earlier, maybe at 3:30am, and continuing until twilight reduces the limiting magnitude to magnitude 5.0.  With the radiant low on the horizon, expect hourly rates between 5 and 10, with a roughly equal number of sporadics.  The low radiant favors earthgrazer-type meteors, which often run "low, long and slow" along the horizon.

SOUTH DELTA AQUARIDS (maximum July 28 [broad])  (radiant drift map)

The South Delta Aquarids are the strongest of a large number of radiants in the constellations of Aquarius, Capricornus and Piscis Austrinus during late July and early August.  The combination of all these radiants with sporadics and early Perseids means that mornings at this time of the year are quite meteor-rich.  I often achieve total rates of 30 meteors/hour from a dark site.  It is difficult to impossible for visual observers to distinguish between all the radiants in the "Aquarid/Capricornid complex", as many are diffuse and overlapping.  But take a look at the radiant drift map.  Any slow to mid-speed meteor that can be traced back to this area of the sky can be labeled an "Aquarid".   The South Delta Aquarid radiant produces maximum ZHRs around 20; from our latitudes, observed rates from this radiant alone will probably be 5-10/hour.

PERSEIDS (maximum August 13, 5h UT [August 12, 10pm PDT])
(radiant drift map)

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.  Even compromised by moonlight and an unfavorable peak time, the 2003 Perseids will be one of the best meteor showers of the year.

A few Perseids are visible starting in mid-July, when the radiant is far from Perseus (see radiant drift map).  During the last week of July, my 2001 observations indicated Perseid rates of about 3/hour.  By August 7, ZHRs exceed 10.  On August 11 a steep increase begins.  This year, bright moonlight will compromise observations; the best times to observe pre-maximum Perseids will be right before the beginning of twilight each morning.

This year, the Perseid maximum occurs as evening twilight is ending in the Pacific Northwest.  Late on the evening of August 12, at the end of evening twilight, the ZHR should approach 100.  Due to the low radiant elevation and the Full Moon lying low in the SE sky, Perseid rates from otherwise dark sites may peak at 20-40/hour along with a few sporadics.  In 2000, with a Full Moon and bright aurora, I was still able to achieve a limiting magnitude of 5.6.  My Perseid rates for the first two hours after the end of evening twilight were 13 and 34; I would expect similar numbers this year.  Perseid rates are respectable for several days after maximum, but will be dragged down by the continued presence of the Moon.

ORIONIDS (maximum October 21 [broad])    (radiant drift map)

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 waning Moon will be a serious hindrance.  The best Moon-free observing will come between October 21-25, when there are reasonable intervals between midnight and moonrise.  Observers may want to monitor the morning of October 18 as well, as outbursts in 1993 and 1998 occurred on this date.  The Moon will be at First Quarter, and reasonable limiting magnitudes are certainly possible from good sites at this phase.

LEONIDS (several maxima in November?)   (radiant drift map)

Strong outbursts of Leonid activity have occurred every year since 1998.  For 2003, there may or may not be increased rates. During 1996 and 1997, peak ZHRs of 40 - 150 were reported.  Several of the meteoroid stream modelers who have been more right than wrong have forecast possible outbursts due to grazing encounters with dust trails in the complex Leonid stream.

The paper describing these predictions can be found at  Briefly, here are the ranges of predicted maximum times.

November 13; 5:15am-10:20am PST
November 18; 4:25pm PST
November 18; 10:30pm- November 19; midnight PST
November 19; 4:50pm-5:30pm PST
November 22; 1:00pm-2:00pm PST
November 22; 6:56pm PST

The two bold maxma are potentially observable from the Pacific Northwest, though marginally so.  For example, a peak time of 5:15am on November 13 would strongly favor the Northwest, while a peak of 10:20am would occur in daylight.  One group of researchers predicts a broad outburst lasting half a day. In any case, with weather permitting NW observers should attempt to monitor the stream on the morning of November 13.  A bright Moon will interfere, and most of the Leonids are expected to be faint.  Visual rates of even 5-10 Leonids/hour would confirm this outburst, however, which takes place outside the normally accepted date range of Leonid activity.  Be extremely careful with shower association to avoid counting sporadics as Leonids.

The "normal" or annual Leonid maximum is expected on the morning of November 18, with expected ZHRs of between 10 and 20 Leonids/hour.  A last quarter Moon will dog the radiant, although decent sky conditions are attainable in rural areas.  Again, watch if you can, but don't expect anything spectacular.  As always, remember that the Leonids are unobservable early in the evening.  Even though the sky may be dark, the radiant doesn't rise until about 11:00 in the Pacific Northwest.  Even then, rates are very low.  1:00am is a good starting time for watches on the morning of the 18th.

The predicted outburst on November 18/19 is also marginally favorable for the Pacific Northwest.  The radiant is below the horizon at the earliest predicted maximum (10:30pm) and still low at midnight.  Again, it is uncertain how long an outburst might last, or what the rates might be.  There is also disagreement over whether this outburst will include an unusual number of brighter meteors and fireballs (see for details on this prediction by Peter Jenniskens and Hans Betlem).  Watches should probably start around 11pm PST.  Expect low or nonexistent Leonid rates, especially at first.  However, in the best case scenario, the display could be similar to the first hour or so of the 2001 Leonids, with a number of beautiful earthgrazers.  We just don't know, and that's why we'll watch.  One positive is that by this time the Moon will be less of a problem, and out of the sky until about 2am. 

GEMINIDS (maximum December 14, ~16h UT [~8am PST])   (radiant drift map)

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 on the morning of December 14.  Unfortunately, a waning gibbous Moon will take some of the luster off this show, if the clouds don't get to it first.  The Moon will rise around 9:00pm on the 13th, just as the Geminids usually start to get interesting, and hang around for the rest of the night.  Like the Perseids, however, the Geminids are worth observing even under moonlit conditions.  Rates could reach 40-50/hour sometime on the morning of the 14th.  The evening of the 14th could also be a good time to watch.

These are the best meteor observing opportunities in the year 2003, 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.

Other Meteor Shower Info.
What the heck is a ZHR?
The Finer Points of Meteor Shower Observing
My Online Observing Log

Outside Links
The North American Meteor Network
The International Meteor Organization
The American Meteor Society
Gary Kronk's Meteor Shower Page

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