James E. Richardson, Jr.

Planetary Scientist

Current Visual Meteor Activity

from the Visual Meteor Database of the Internationa Meteor Organization

The purpose of this website is to show interested members of the general public and astronomical community the level of meteor activity observed in the night sky during the last quarter and year. This website will be updated weekly, utilzing data supplied by the observers of the Internaional Meteor Organization (IMO) to their Visual Meteor Database (VMDB). The plots contained on this page do not represent a rigorous scientific analysis, but are instead intended to convey what active observers are reporting with minimal filtering or processing. The legend at right shows the twenty catagories into which this data is divided: (1) the sporadic, or randomly distributed meteors, including the Antihelion source area; (2) the ten most active "major" (M) meteor showers; (3) eight variable (v) meteor showers, some of which occasionally produce outbursts; and (4) all other "minor" meteor showers grouped together. Note that large time gaps in the visual observer data generally indicate either near full Moon or inclement weather conditions.

For more information, including how to conduct meteor observations and contribute to this database,
please visit the websites of the American Meteor Society (AMS) and the Internationa Meteor Organization (IMO).



Contents



Current quarter: uncorrected visual meteor hourly rates

Reported, uncorrected visual meteor hourly rates -- the number of meteors counted divided by the effective time spent actively watching the sky in each 1-hour observation interval -- for the current quarter (past 90 days). Shower identifications are made by the observer tracing the meteor's path back to a known meteor shower "radiant" point in sky and gaging the meteor's angular speed as typical for that known shower. Note the logarithmic scale used for the vertical axis of these plots.

Current quarter: corrected visual meteor hourly rates

Corrected visual meteor hourly rates for the current quarter (past 90 days). The reported hourly rates from Fig. 1 have been corrected for (a) the observers effective field-of-view, as affected by clouds and ground obstruction, (b) the clarity and darkness of the observer's sky, as affected by light pollution and atmospheric haze, and (c) for our selected individual shower meteors, the angular altitude of the shower radiant in the sky. These corrected, standardized rates tend to be a few times higher than the actual, observed rates.

Current year: uncorrected visual meteor hourly rates

Reported, uncorrected visual meteor hourly rates -- the number of meteors counted divided by the effective time spent actively watching the sky in each 1-hour observation interval -- for the current year (past 365/6 days). Each major shower stands out as a separate peak against the constant background of sporadic and minor shower meteors. Note that the number of identified sporadic meteors appears to peak at the same time as each major shower, indicating that a fraction of the shower meteors failed to be properly identified as such, and thus fell into the unassociated, "sporadic meteor" category.

Current year: corrected visual meteor hourly rates

Corrected visual meteor hourly rates for the current year (past 365/6 days). The reported hourly rates from Fig. 3 have been corrected for (a) the observers effective field-of-view, as affected by clouds and ground obstruction, (b) the clarity and darkness of the observer's sky, as affected by light pollution and atmospheric haze, and (c) for reported major shower meteors, the angular altitude of the shower radiant in the sky. Note that although not readily apparent in this data, the sporadic meteors also experience a gentle annual variation, with a high in the norther-hemisphere summer months and a low in the northern-hemisphere winter months.

Individual meteor showers over the past year

The horizontal, time-scale banding / striping in the plots below occurs because most of the IMO's observers are located in Europe, where most meteor observations center on local midnight near 0-1h UT. Meteor counts that occur between these bands are likely from other regions of the world and more distant time zones. The wide, vertical spread in meteor counts that occur at about the same observation time is because although the average meteoroid density in the shower stream undergoes a relatively smooth ramp-up and ramp-down as the Earth passes through it, the meteoroids themselves are randomly spaced, with frequent clusters and voids. As such, one location may experience a much higher than average number of meteors while another location may experience a much lower than average number of meteors in the same hour. Relatively young meteoroid streams will have narrow peaks that occur over a short period of time, while relatively old meteoroid streams will have broad peaks that occur over a longer period of time (although both depend upon the geometry of the intersction of the Earth's orbith with the stream's orbit). Sporadic meteor rates are included to indicate when active observing sessions were in progress.

IMO VMDB observation locations: current and previous year

A map plot of the observation locations used by IMO observers to produce the data contained in these plots. Note the heavy concentration of observatons in the northern hemisphere, particular in Europe and North America, indicating the continuing need for greater world-wide coverage, particularly in the southern hemisphere.

Additional Notes

These figures were produced with the Interactive Data Language (IDL) using a license provided by the Planetary Science Institute (PSI). The code also makes use of functions and procedures contained within the Coyote IDL Program Libraries and the IDL Astronomy User's Libary. Please contact the author for further details: contact information can be obtained from either the Curriculum Vitae or Resume linked to on my home-page (see the link at the top of this page).

Each non-zero count reported by an observer is included in the above plots without data quality filtering or averaging. As such the following limits are placed on the correction factors used:

The author would like to sincerely thank the observers of the International Meteor Orgainzation for their extreme dedication to the field of meteor science, one of the last bastions of naked-eye astronomy.



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