Visual Observing

Two April Lyrid meteors and one sporadic meteor recorded by then novice plotter James Richardson in the early morning hours of April 22, 1990, from Loma Prieta peak, California.

Introduction

Meteor Science is one of the few remaining astronomical fields where amateur astronomers, equipped with only their eyes, can provide a valuable service to the planetary science community. Because bright city lights and cloudy weather often prevent us from viewing the sky, chances are that few observers, if any, are watching meteors on any particular night. Brief meteor outbursts and bright fireballs can occur unnoticed. So, if you watch the sky, you may be the only observer of one of these rare events. When more observers watch each night, there is a better chance of observing and reporting fleeting meteor spectacles. This is the reason we encourage all observers to take advantage of clear skies and to observe meteor activity as often as possible.

Charles Olivier formed the American Meteor Society in 1911. The new organization’s goals were promoting and managing amateur participation in the field of meteor astronomy. Nearly one hundred years later, the society’s visual observers are still scanning the skies for meteoric activity and reporting their observations. Today, global communication is nearly instantaneous and it is far easier to provide activity alerts and to share your meteor data with the world’s observers.

The purpose of this page is to provide (on-line) the forms and instructions used by participants in the AMS Visual Observing Program to record their meteor data collected in the field, as well as presenting periodic reports on the visual meteor activity seen by our observers. Once received by the visual coordinator, copies of these data are then distributed to other interested organizations, such as the International Meteor Organization (IMO), as well to as individual amateur and professional astronomers (both AMS and non-AMS) who are interested in utilzing the data for a particular study. Additionally, this page also contains a number of papers and articles written by present and past AMS affiliates on the topic of techniques for visual meteor observing and data reduction.

For more information and instructions on getting started in this endeavor, please contact our Visual Observing Program coordinator, Robert Lunsford.

Meteor Viewing Basics

We all at one time or another have seen a shooting star zip through the heavens. If you are interested in increasing the odds of seeing this phenomena, there are some important factors you should consider:

On an annual scale, from the northern hemisphere, more random (sporadic) meteor activity will occur during the second half of the year. From the southern hemisphere, almost the opposite is true with the first half being more productive. There are actually two peaks visible from the southern hemisphere, one in January and the other in early July. It was once thought that the angle of the ecliptic during different seasons played a role in this variation. Studies have revealed that there is simply more activity to be seen from weak and unrecognized radiants, producing the sporadic meteors, during these times of year from each hemisphere.

On a daily scale, dusk is the worst time to view meteor activity. The reason for this is that at this time, you are viewing the area of the sky from which the Earth is receding. Therefore any meteor must catch up to the Earth in order to be seen. This is often compared to a vehicle driving through rain or snow. One will see more raindrops or snowflakes hitting the front windshield compared to the rear window. At this time you are looking through the rear window.

As the night progresses the numbers of meteors visible will increase. As the Earth rotates toward the apex (the point in the sky where the Earth appears to be traveling toward), meteors striking the Earth from perpendicular angles and those striking the Earth from head-on will become visible. The best time to see meteor activity would be the period just before the start of morning twilight, when most of the meteors will be striking the Earth from a “head-on” position, much like looking through the front windshield of a vehicle during rain or snow.

There is even a more important factor when trying to see meteor activity; is there an active major meteor shower visible tonight? If there is then you have the opportunity of seeing up to ten times the normal numbers of meteors visible. There are only nine meteor showers than are considered major. They are the Quadrantids (Jan 3-4), Lyrids (Apr 22), Eta Aquarids (May 2-10), Delta Aquarids (Jul 26-30), Perseids (Aug 5-19), Orionids (Oct 18-26), Leonids (Nov 18), Geminids (Dec 10-16), and the Ursids (Dec 22). These major showers vary in intensity but all are best seen during the early morning hours. Viewing the morning sky during these periods will offer much more activity as these showers will combine with the normal sporadic activity to produce a good show. The absolute ten best mornings for viewing meteor activity are: (in order of strength) Dec 14, Aug 12, Dec 13, Aug 11, Aug 13, Jan 3, Dec 12, Oct 22, Aug 10, and Dec 11. Since the Earth encounters these showers every year at the same time, these dates will usually remain the same year after year.

Finally, the sky must be as dark as possible for you to see the most activity. If the moon is above the horizon, it will certainly brighten the sky. There are years when a bright moon will ruin most of the dates above. There is nothing you can do about this coincidence except put up with the moonlight or wait until the next favorable date. December 14 and August 12 (the peak mornings of the Geminids and Perseids) will still produce more activity with moonlight than all the others without. They should not be missed regardless of the conditions.

There are other factors to help you see more activity that are more within your control. The location of your watch is important. Since city lights will obscure the fainter meteors, it would help immensely to watch from darker rural skies. Viewing comfort is also desirable. You should use a reclining lounge chair so that you are comfortable. It is also a good idea to nap before a watch and to be well rested when attempting to observe. You certainly will not see much meteor activity through closed eyelids!

If you consider these factors when planning your observing schedule, you will surely see enough meteors to fulfill all your wishes!

Suggested Observing Strategies

The most popular strategy is to view when meteor activity is strongest. Besides, who wants to be out when one sees only one or two meteors per hour? That’s about as exciting as watching the grass grow! There are approximately ten mornings each year when the meteor activity is exceptional. This is when a majority of the meteor observers are out. This is also when the year round observers get rewarded for their efforts. Wouldn’t you know it though that a majority of these nights have a full moon or are clouded out! Well, it seems that way to a lot of us who have been around for a long time.

What about the other 355 nights per year? Well, these are the nights when real discoveries are made and surprises lie in wait. Yes there are those nights when the activity is so sparse one can barely stay awake. Yet it’s the fact that you might be the only person on earth at that moment concentrating on meteor activity that keeps you going. Who knows, you may witness a rare meteor from the Tau Herculid shower or the start of a flurry of activity from the June Bootids. Sometimes there is an unexpected display of activity from a new or dormant radiant. While the major showers are the most entertaining, real discoveries are made on nights when nothing out of the ordinary is expected.

There is at least one minor shower active each night of the year. There are radiant lists where a hundred or more showers are listed. Recent studies using unbiased video equipment has shown that there are only three dozen radiants active throughout the year that produce enough activity that is easily visible to the unaided eye. Less than a dozen of these produce rates of ten meteors per hour or better. The other two dozen produce rates lower than the sporadic background. These minor showers are often ignored and are in need of constant monitoring.

The American Meteor Society encourages observers to monitor these minor showers so that any abnormal activity may be observed and reported. Occasionally we also ask observers to monitor the skies on selected dates to verify activity reported earlier. For motivated observers, the A.M.S. also encourages observations on nights when little or no activity is expected. It is these observations that alert us to new activity and the prospect of a new shower in years to come.

AMS Visual Meteor Observing Forms and Instructions

Visual Meteor Observing Papers and Resources