Major Meteor Showers in 2016
In 2015, both the Perseids and the Geminids were favored by good moon-phase circumstances. The Orionids and Leonids were also relatively free of moonlight interference, and many observers reported good rates. I wasn't able to get out as often as I would have liked, but I did see an excellent Perseid maximum from the dark skies of the Oregon Star Party. My sole Orionid morning was nothing special, and I only got to observe the Geminids through sucker patches in the clouds.
In 2016, most of the major showers have some moonlight interference, but there will be opportunities to observe as well. The Perseids should be the best shower of the year. This is a leap year, so the predicted maxima of regular showers (other than the Quadrantids) are shifted 18 hours earlier on our calendars vs. last year.
Basic Meteor Observing Information
Several factors determine how many meteors you will see from a shower.
* One of the most important is the elevation of the shower's radiant when you're watching. For most showers, the radiant is highest in the morning hours, and that's when you can expect the best rates. If the radiant is near or below the horizon, don't expect to see any shower meteors even if the sky is dark. For each shower, I list a "WHEN TO WATCH" window when the radiant is at a useful elevation. The local times I list in "WHEN TO WATCH" should be broadly valid for most sites in North America, regardless of your time zone or exact location. You may want to look up the beginning of morning astronomical twilight for a given date at your location. This can be found from planetarium software or some weather websites. I find that skies are still good enough for meteor observing for 15-30 minutes after the beginning of morning twilight.
* Clear, dark skies are essential for a rewarding meteor-watching experience. This is why the moon causes so many problems--it's just natural light pollution. Get away from artificial light pollution as best you can--don't expect to see many meteors from an urban or suburban location. The light wipes out the fainter meteors and makes the moderately bright ones less noticeable. Try to get to a location where the Milky Way is obvious on a summer night. Obviously, clouds are a deal-breaker as well.
* The actual activity level of the shower has a big impact, of course. But I put it third on the list of factors because you have little control over it. The year's best showers generally have one night/morning that they are most active. The peak of activity may last for a few hours to many hours, but the exact timing is usually uncertain. Nevertheless, I list the "predicted maximum" time for each shower (based on past observations and the IMO Meteor Shower Calendar) along with conversions to Pacific and Eastern times. If the peak time occurs during your daylight hours (or during the night but before the radiant is high in the sky), pick the productive observing time that is nearest the peak (my "WHEN TO WATCH" gives suggestions).
* Your personal visual perception and experience also factor into how many meteors you see. For best results, make sure your eyes are dark-adapted (don't expose them to any bright or not-so-bright lights for a half-hour or so before you begin observing) and that you are comfortable.
* I get quite a few questions about "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...
Not all the meteors you will see belong to the major shower. Sporadic (random) meteors are visible every night of the year. From dark sites, 5 to 15 or more sporadics may be seen each hour. Sporadics are most numerous in the predawn hours, when the Earth is running head-on into a lot of cometary debris. There are also minor showers active at the same time as most major showers. Most of these produce 0 to 2 meteors per hour even at peak activity.
When a meteor appears, make a note of its path against the stars. Hold a long shoestring or cord up against the sky at arm's length along this path. If you extend the meteor's path *backward* along the cord, does it eventually cross or come close to the shower's radiant as shown on the radiant map for that date? If so, the meteor was probably a shower member. If not, the meteor was not a shower member.
QUADRANTIDS
Predicted Maximum: January 4, ~07:30 UT (= January 3, 11:30pm PST; = January 4, 2:30am EST)
Moon: Waning Crescent (moderate interference)
WHEN TO WATCH: All observers will want to watch on the morning of Monday, January 4th. The radiant is highest just before the beginning of morning twilight, but mid-northern observers might want to start watching as early as 1 or 2 am. Eastern North America is favored by the predicted maximum, but IMO cites a model that predicts an earlier peak time which would favor European observers. You can't be sure of much with the Quadrantids.
The peak of this shower usually doesn't last long, and is notoriously variable in strength and timing and duration. The weather is often horrible as well. The best peaks, such as in 2009, are impressive indeed and produce rates of over 100 per hour.
Quadrantids are medium-velocity meteors. The shower usually produces quite a few fireballs 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 IMO radiant map). In addition to shower members, quite a few sporadics (random meteors not associated with a known shower) are visible from dark sites this time of year.
Weather in my area was not good for the Quadrantid maximum. I went out for a little bit under a hazy, partially obscured sky and saw 9 Quadrantids in 20 minutes (10:33-10:53 UT).
LYRIDS
Predicted Maximum: April 22, ~6:00 UT (= April 21, 11:00pm PDT; = April 22, 2:00am EDT)
Moon: Full Moon (major interference)
WHEN TO WATCH: The Full Moon makes this a washout. Die-hard observers can go out on the morning of Friday, April 22nd between midnight and morning twilight.
The Lyrids are another shower with a reputation for variable rates and timing. Usually, they produce about 10-20 meteors per hour at maximum (under dark skies). There won't be any dark skies this year--expect to see a few Lyrids per hour at best. Lyrids produce fairly fast meteors with a reputation for being faint on average. However, I've seen my share of Lyrid fireballs.
ETA AQUARIDS
Predicted Maximum: May 5-6 (broad)
Moon: New Moon (no interference)
WHEN TO WATCH: The Eta Aquarids are only visible for a short period around the time morning twilight begins. The peak should occur on May 5th or 6th, but the adjacent mornings could be productive as well. The key is to watch during the last bit of darkness and through astronomical twilight (see below for timing).
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 3:30-4:30am local daylight time. Observers from mid-northern latitudes might expect 5-15 Eta Aquarids and a few sporadics during the last hour of not-so-darkness.
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 28-30 (broad)
Moon: Waning Crescent (moderate to minor interference)
WHEN TO WATCH: This shower's maximum seems to be broad and irregular. During the last week of July, the Moon goes from Last Quarter to New, rising later and becoming less of an issue each morning. Start watching at 1 or 2 am and continue through the beginning of morning twilight on any morning between Thursday, July 28th and Sunday, July 31st.
The South Delta Aquarids are barely a major shower from 40 degrees N; southern observers have a somewhat better view. On a clear, moonless morning a North American observer might see 5-10 South Delta Aquarids each hour along with 15-25 meteors from other sources. A number of minor meteor showers are active at this time, and the Perseids are just getting started, producing a couple of meteors per hour in the early morning. The total number of meteors can be very impressive from a dark site.
Most of the activity you'll see will be faint, so get away from light pollution and avoid the moonlight hours. The South Delta Aquarids tend to be faint on average, but I have seen a few fireballs over the years. The nearby Anthelion and Alpha Capricornid minor shower radiants have a reputation for producing some fireballs. It is often difficult to tell which radiant a meteor came from (see The Finer Points of Meteor Shower Observing for more details), but you don't have to know in order to enjoy the show!
I observed for 1.5 hours on the morning of July 30 and 2 hours on July 31. I counted 8 South Delta Aquarids among 41 total meteors on the 30th, and 15 South Delta Aquarids among 53 total meteors on the 31st. Skies were OK with just a little smoke.
PERSEIDS
Predicted Maximum: August 12, ~13h UT (=August 12, 6am PDT; =August 12, 9am EDT)
Moon: Waxing Gibbous (minor to moderate interference)
WHEN TO WATCH: The moon phase means that casual Perseid watchers who go to bed before midnight will probably be disappointed by washed-out skies and few meteors. For serious observers who know that the radiant is highest in the morning hours, this could be a very memorable Perseid year. The absolute best time to watch will be on the morning of Friday, August 12th between about 1am and 5am (or whenever morning twilight becomes too bright at your location). Because the shower's peak is fairly broad, it will also be worthwhile to observe during the last few hours before morning twilight on Thursday morning, August 11th and Friday morning, August 13th.
The Perseids are probably the most-watched annual meteor shower. The shower has a very long duration, from about July 15th through August 25th, but is most interesting around its peak on August 12th or 13th. In recent years, the exact timing of the peak has varied somewhat from the predictions. From dark-sky sites, anywhere between 60 and 120 Perseids per hour is realistic on the morning of the 12th. Perseids aren't the only meteors out there--there are minor showers and random sporadic meteors. These "extras" can add 10-20 meteors per hour to the total seen from dark sites. Even casual observers have the chance to pick out some obvious non-Perseids that can't be traced back to the head of Perseus.
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. That's why rates are usually better in the morning hours. The bright moon makes things even worse for evening observers this year. Perseids are fast meteors and tend to be fairly bright on average. An occasional fireball is seen, especially around the maximum.
Skies were clear for me during the Perseid maximum. I saw 292 Perseids and 55 other meteors during a 3.25-hour session on the morning of August 12th. Rates had really fallen off by the morning of the 13th--I saw 46 Perseids and 22 other meteors in 83 minutes.
ORIONIDS
Predicted Maximum: October 21? (broad and irregular)
Moon: Waning Gibbous (major interference)
WHEN TO WATCH: This is a bad year for the Orionids. During the maximum, the Moon is a fat waning gibbous not far from the radiant in northern Orion. If you really want to watch, you might want to wait for the end of the activity period, between October 23rd and 25th, and watch from midnight to 2am.
The Orionids are capable of producing interesting activity from October 17th through the 25th. Traditionally, the shower produces maximum rates of about 25 per hour, with occasional enhancements to 50 per hour occurring irregularly. The shower seems to produce spurts and lulls, so one morning (even around the predicted maximum) may be very dull while the next morning is very active. I never know what to expect from this shower. This year, the Moon is bright and in a really awkward position. I suppose you could try to block it behind a tree or tall building and face away from it to see Orionids in other parts of the sky.
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 (see the radiant map). The Orionids are joined by several minor showers (the Taurid complex, the Epsilon Geminids, and the Leonis Minorids) that each typically produce 1-2 meteors per hour.
LEONIDS
Predicted Maximum: November 17, ~10:00 UT (=November 17, 2:00am PST; =November 17, 5:00am EST)
Moon: Waning Gibbous (major interference)
WHEN TO WATCH: The Moon essentially washes out the Leonids this year. If your skies are really clear and dark and you are a die-hard observer who needs to see a few Leonids, your best bet is to go out on the morning of Thursday, November 17th during the last few hours before morning twilight.
The Leonids are very fast meteors. The shower is active at a low "background" level for up to a week before and after the maximum.
GEMINIDS
Predicted Maximum: December 13, ~12h? UT (=December 13, 4am PST; =December 13th, 7am EST)
Moon: Full Moon (major interference)
WHEN TO WATCH: The Full Moon is up all night during the Geminid maximum. The shower is prolific enough and rich enough in bright meteors that if your weather is good you may still want to go out. Just don't expect the 100 meteors per hour that you might see under dark skies. Maybe 10-20 is a better guess if there isn't snow on the ground or haze in the air. If I had to pick a time, I would go out between 2am and 6am on Tuesday, December 13th and face east. Some areas will also get a brief moon-free period right before morning twilight on Monday, the 12th, and there will be over an hour of dark skies on the morning of Sunday, the 11th. These periods could potentially produce Geminid rates as high as those on the 13th.
The Geminids show a broad peak that is somewhat variable in timing. This is often considered the best annual shower, especially in locales where winters are mild. An old rule of thumb is that Geminid rates double on each of the last few mornings leading up to the peak (e.g., 10 per hour on the morning of the 10th; 20 per hour on the 11th; 40 per hour on the 12th; and 80 per hour on the 13th). Rates usually drop precipitously after the peak (down to perhaps 20 per hour on the morning of the 14th). The moon will make a mess of that rule of thumb this year.
Southern Hemisphere observers also enjoy this shower, although with lower rates and a shorter viewing period in the predawn hours.
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.
I got in a couple of short casual Geminid watches during cloud breaks. On the morning of December 12th, I watched for 13 minutes from 5:21-5:34am PDT and saw 4 Geminids, 1 Sigma Hydrid and 1 sporadic. On the morning of the 13th, I watched for 52 minutes from 5:00-5:52am PDT and saw 21 Geminids and 1 sporadic. I saw a couple of fireball-class Geminids on the 13th, both bright white with a violet tinge.
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Other Sources of Meteor Activity
The major showers listed here 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. Rarely, many of the meteors seen may be members of a periodic or previously unknown shower. 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 and predicted times of maximum are adapted from personal data and also from the International Meteor Organization's 2016 Meteor Shower Calendar. Recent data at http://www.imo.net/zhr was also examined. Links to radiant maps direct to http://www.imo.net. All on-site text and contents are Copyright 2015 by Wes Stone and may be reproduced for not-for-profit use so long as credit is given.
