Major Meteor Showers in 2007
In 2006, the Moon plagued the Perseid maximum, but the rest of the major showers fared much better. The highlight was an unexpected outburst of the Orionids over several mornings with ZHRs approaching 60. My peak hour from a dark-sky site featured 74 Orionids! A brief, well-predicted Leonid outburst was observed from Western Europe.
2007 starts out slow with the Quadrantid maximum washed out by moonlight. April's Lyrids, on the other hand, are Moon-free. The Moon again interferes with the Eta Aquarids in May and the Aquarid complex activity at the end of July, but this means that the Perseids are perfectly placed. The most anticipated event of the year is an anticipated outbust of the usually minor Alpha Aurigids on the morning of September 1. Activity level estimates range widely, and the Moon will wipe out faint meteors, but models suggest that the shower will be rich in bright meteors. Was last year's Orionid display a fluke? We don't know, but the shower is worth watching. The Leonids should be down to low levels, but this "background activity" could produce some surprises. Finally, there are excellent circumstances for the Geminids at the end of the year (weather permitting, of course).
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. Best viewing windows are suggested for each shower. The information about viewing windows is primarily targeted to North American observers.
Vagaries of meteor activity, your personal ability to perceive meteors, and local sky conditions may all dramatically affect 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 observing meteors. More shower meteors are visible from a dark site, and sporadic (random) meteor rates are enhanced greatly.
QUADRANTIDS (maximum January 4, 0h UT [January 3, 4pm PST; 7pm EST])
Moon: Full Moon (major interference)
Best viewing window: None. The brilliant Moon will rise early and set late.
Recommended for: Insomniacs?
Peak Quadrantid rates rival those of the Perseids and Geminids. However, the shower has a very sharp and variable maximum (possibly several hours later or earlier than the predicted time given above), and early January often features unforgiving weather. That makes this a difficult shower to catch at its best. This year, Full Moon adds to the obstacles.
Quadrantids are medium-velocity meteors, and some bright ones are often visible at maximum activity. The radiant is in a rather blank area surrounded by the constellation figures of Bootes, Hercules, Draco and Ursa Major (see radiant drift map). Off-maximum nights only produce a few shower members; the shower has a very short duration from about January 1-5.
LYRIDS (maximum April 22, ~22hUT [3pm PDT; 6pm EDT])
Moon: Waxing Crescent (moderate interference)
Best viewing window: Midnight until morning twilight on Sunday morning, April 22 and again on Monday morning, April 23.
Recommended for: Anyone interested in serious meteor observing.
The Lyrids have produced a few exceptional displays in the past, but on a normal annual basis they are just barely a major shower. Typical maximum rates are 10-20 per hour. The time of maximum is rather variable, as is the shower's full width at half of maximum strength. The predicted time of maximum is not favorable for North America (occurs during daylight hours), so rates of 5-10 per hour may be more realistic. Sometimes the maximum is fairly sharp; in other years, there has been a pronounced plateau of near-maximum rates lasting for many hours. The Moon will be a fat crescent, and is far north so it will set after midnight and interfere somewhat with observing.
Lyrids produce fairly fast meteors with a reputation for being faint on average.
I was able to observe for two hours on the morning of April 23. I saw 41 meteors including 15 Lyrids under good sky conditions. More information is in my observing log.
Moon: Waning Gibbous (major interference)
Best viewing window: The Moon is a major hindrance this year, adding to the difficulties in observing this shower. If you want to try anyway, focus on the last hour or so before twilight gets really bright (depends on your latitude and also on your longitude with respect to the center of your time zone). At latitude 42.6 degrees North, I've had my best results from about 3:40-4:40am local daylight time. At latitude 35 North, you might want to begin 15 minutes earlier and end up to a half-hour later. Sunday morning, May 6 might be the "best" morning, or not...
Recommended for: True die-hards.
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 you could get those conditions for an hour, you might see 10-15 ETAs. However, everything's changing. Before that time, you're seeing fewer shower members because the radiant is lower. After that time, the radiant is higher and rates keep rising, but all too soon the full brunt of twilight wipes out your dark skies. You're fortunate indeed if you see 10 ETAs in an hour, along with about 5 sporadic (random) meteors. This year, the Moon will probably cut these numbers by more than half. Southerners have the radiant above the horizon longer, but also have the Moon higher.
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, low 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. One good thing about the Eta Aquarids is the long duration of the shower: rates near maximum may be maintained for several days. The shower also seems to fluctuate irregularly, so you could easily hit either a spurt or a lull. Try the mornings of May 5, 6 and/or 7 this year, and maybe you'll get lucky.
SOUTH DELTA AQUARIDS (maximum July 29 [broad])
Moon: Full Moon (major interference)
Best viewing window: The last hour before morning twilight on Friday morning, July 27.
Recommended for: Early risers who want to brush up on their meteor observing before the Perseid peak.
The South Delta Aquarids are barely a major shower from 40 degrees N. They are part of a complex of radiants in Aquarius, Capricornus and Piscis Austrinus, all of which combine with sporadic and early Perseid activity to provide a nice display of meteors on moonless mornings in late July. The stream normally produces about 5-10 meteors/hour, with overall activity of about 30/hour under good conditions. This year the Full Moon severely restricts observing near the maximum, but a decent number of meteors should be visible a couple of days beforehand.
The South Delta Aquarids are medium-speed meteors, and tend to be faint on average. Meteors from this stream are easily confused with those of several minor showers with nearby radiants. The Piscis Austrinids have a radiant near the bright star Fomalhaut. A weak, diffuse radiant called the "anthelion" or "eclipticids" is also nearby. Farther west is the Alpha Capricornid radiant, which produces slower, often impressive meteors. You may not be able to assign every shower meteor to its correct radiant, but that doesn't mean you can't enjoy the show!
The faintness of most of this activity and the large number of faint sporadics mean that a dark sky is almost essential to the appreciation of this late-July enhancement of meteor rates. The radiants are higher in their sky for southern observers, but the Moon is still a pain. The best viewing window above reflects a short period between moonset and morning twilight.
PERSEIDS (maximum August 13, 5h UT [August 12 @ 10pm PDT; August 13 @ 1am EDT])
Moon: New (no interference)
Best viewing window: Sunday evening, August 12, from the end of evening twilight until morning twilight on Monday morning, August 13. Sunday morning, August 12 should also be pretty good during the predawn hours.
Recommended for: Anyone interested in meteors.
The Perseids are probably the most-watched annual meteor shower. The shower has a very long duration, from about July 15 through August 25. The shower is most interesting around its peak on August 12 or 13. This year, the Moon is perfectly placed and will not interfere for several days before and after the maximum. The shower's normal peak time favors observers from eastern North America to western Europe, but everyone should get a good show on peak night.
The 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. Evening Perseid rates are low, then, but there are usually enough meteors to be interesting. Serious observers will watch all night long.
Predawn rates for observers with truly dark skies may exceed 80 Perseids per hour, with a nice sprinkling of sporadic and minor shower meteors added to the mix. Adjacent mornings from August 10 through August 15 are well worth watching, although rates will be significantly lower (down to 10 Perseids/hour at the extremes).
Perseids are fast meteors and tend to be fairly bright on average. An occasional fireball is seen.
Note: Perseid reports from August 11-14 are available in my Online Observing Log. Perseid activity was about normal, but sky conditions on the 12th and 13th were excellent leading to high observed rates for me. The morning of the 14th was also enjoyable.
ALPHA AURIGIDS (maximum September 1, 11:33 UT [4:33am PDT; 7:33am EDT]
Note: Aurigid outbust did occur on the morning of September 1 with low to moderate rates (quick ZHR calculation: 68 +/- 14). See my observing log for full report.
Moon: Waning Gibbous (major interference)
Best viewing window: The last couple of hours before morning twilight becomes too bright on Saturday morning, September 1. Strongly favors the West Coast of North America.
Recommended for: Anyone interested in meteors, especially if you live where it's dark and the radiant is above the horizon during the predicted maximum.
The Alpha Aurigids (sometimes referred to as the Theta Aurigids or just the Aurigids) are apparently an annual shower, but usually a minor or irregular one. On several occasions, they have produced memorable outbursts of dozens of bright meteors per hour. Leading meteor experts predict another such outburst in 2007 with potentially very high rates. Besides the uncertainty that always goes with predictions of meteor rates, there are several catches. First, the outburst is likely to be short-lived, lasting perhaps just one hour around 4:33am PDT (correct this for your time zone). Secondly, only areas where the sky is dark and the radiant is (well) above the horizon will see much of the outburst. These factors combine to favor western North America west to Hawaii. Thirdly (wouldn't you know it?) the Moon will be bright and unavoidable. Luckily, the past outbursts were fairly rich in bright meteors.
Rate estimates seem to have been revised downward. The best guess is that a very sharp peak of over 100 per hour could last up to 30 minutes. With the moonlight interference, favored observers might expect to see somewhere between 20 and 100 meteors in a one-hour period. There's a lot of room for variation, but there is general agreement that the outburst will happen.
Aurigids are fast meteors (when the radiant is well above the horizon). Bright ones should leave persistent trains, and there is a history of brightly colored meteors from this stream.
More information:
Aurigid Predictions for 2007 September 1 by Jenniskens and Jeremie Vaubaillon (a very important reference if you can wade through it, as it illustrates the assumptions made in predicting meteor rates)
NASA's Bill Cooke)
ORIONIDS (maximum October 21 [broad and irregular])
Moon: Waxing Gibbous (minor interference)
Best viewing windows: Saturday, Sunday and/or Monday mornings, October 20-22. 2am - 6am local daylight time are the best hours as the radiant is highest then. Other mornings in the period of October 17-25 may also be productive. The Moon sets earlier during the first part of the shower period, allowing more dark-sky time.
Recommended for: Anyone interested in meteors.
The Orionids are capable of producing interesting activity from October 17-25. Maximum rates seen from a dark site may reach 20-25 per hour, but sometimes there are lulls even around the traditional maximum of October 21. 2006 gave us a huge surprise with rates more than double those expected for several mornings around the peak. What, if anything, this means for 2007 is unclear. Any given morning session may be more or less interesting than expected. In any case, clear mornings during the activity period are always good times to look for meteors from dark sites.
The Orionids are fast meteors, perhaps a bit faint on average but capable of producing fireballs. The 2006 outburst featured brighter-than-normal Orionids. 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. Early activity from the Taurids can produce a few nice, slow meteors from radiants farther west. Finally, 5-15 sporadic meteors are usually visible each hour from dark sites.
Note: Another good year for the Orionids; I only got to watch on the morning of the 21st. I saw 100 in about 1.75 hours under good skies with a bit of fog.
LEONIDS (maximum November 18; 3h UT
[November 17; 7pm PST; 10pm EST])
Moon: Waxing Gibbous (minor interference)
Best viewing window: The maximum is not well-defined. The predawn hours of Sunday, November 18 may be the best bet. Morning observing is a must for the Leonids, as the radiant rises late.
Recommended for: Anyone interested in serious meteor observing.
No unusual Leonid activity is predicted this year; it is probable that rates will be low. Even dark-sky observers should expect only 5-15 Leonids per hour (possibly outnumbered by sporadic meteors) on the mornings of November 17-19, although the shower could always have a surprise in store.
The Leonids are very fast meteors. The shower is active at a low "background" level for about a week from November 14-21.
GEMINIDS (maximum December 14, ~17h UT [9am PST; noon EST])
Moon: Waxing Crescent (minor interference)
Best viewing window: Friday morning, December 14 from midnight until morning twilight. (Viewing can be productive even before midnight).
Recommended for: Anybody with clear skies on maximum night!
The Geminids are a beautiful, prolific and reliable shower. While December nights can be bone-chilling, for many areas sky transparency is better than it is during the August Perseids. Unfortunately, I don't live in one of those areas, but I'm not bitter. Really...
The Geminids are also accessible for many Southern Hemisphere locations, unlike the Perseids. The radiant is highest in the sky at around 2am, but from mid-northern latitudes it is at a decent elevation from around 10pm until the beginning of morning twilight. This year, a waxing crescent Moon will set fairly early on peak night and shouldn't be a problem
The Geminids can produce observed rates of up to 100/hour at maximum. The timing of the peak isn't ideal for North America this year, but it still should be a good show. The shower often shows a plateau-like maximum, with near-maximum rates being sustained for many hours before dropping off rather sharply. Decent numbers of sporadic meteors (~10-15/hour from dark sites) will add to the display.
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 proportion of bright meteors and fireballs is higher during and after maximum than on pre-maximum nights. The shower is active from December 7-17. Both December 12/13 and December 14/15 are worth watching in addition to the peak night.
Note: I actually got in two Geminid observing sessions this year. Too bad it was in the middle of a work week, but I'll take what I can get. The last time I observed the peak night of the Geminids from such dark and cloud-free skies was 1993!
Here are a couple of short notes on the sessions. Full reports will come after I'm completely conscious.
The appetizer:
2007 December 12/13; 1239-1341 UT. Teff~1.0h
Skies were really iffy with some fog and cirrus, but managed to stay clear. Average limiting magnitude was 6.0. In one hour, I observed 19 Geminids, 1 Sigma Hydrid and 7 Sporadics. The brightest meteor was a -2 Geminid.
The main dish:
2007 December 13/14; 0744-1021 UT. Teff~2.5h
Skies were remarkably good for peak night with average LM of 6.8. In 2.5 hours, I observed 235 total meteors, including 207 Geminids. There were lots of spurts and lulls. The highlight of the night was a -4 Geminid, very long and vivid blue with a wake. This color was duplicated in a -2 just before I signed on.
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Other Sources of Meteor Activity
The major showers listed here are fairly reliable and occur every year. The "best viewing windows" indicate the local times when the highest rates should be visible. 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 attributed to a common radiant.
There are some periodic, irregular, and hypothetical showers that could produce surprises during 2007. If news updates warrant, synopses of these showers will be added to this page. The meteorobs mailing list is a good way to keep track of these developments.
Other Meteor Shower Info.
Outside Links
General shower attributes, radiant maps and predicted times of maximum are from the International Meteor Organization's 2007 Meteor Shower Calendar. All other on-site text and contents are Copyright 2006, 2007 by Wes Stone and may be reproduced for not-for-profit use so long as credit is given.
