Tallying The World's Planetarium Attendance by Mark C. Petersen, Loch Ness Productions A periodic posting, prepared 8 March 2010 "In any given year, how many people visit the world's planetaria?" This simple question is an important one, as it reflects upon the very viability and importance of our profession, and the dome theater itself as a media outlet and dispenser of enlightenment -- astronomical and otherwise. Since 1990, I've collected annual attendance figures for planetaria in the Loch Ness Productions database. School shows, public shows, concerts, laser shows, whatever and altogether -- how many humans experience the simulated environment of the starry sky under a planetarium dome? To date I've received responses from about 15% of the world's planetarium facilities, enough to put together a "rough estimate". For some additional observations and disclaimers, please see . A quick explanation about my methods. First, since the United States has nearly as many planetaria than the rest of the world's countries combined, it makes sense to separate out the U. S. responses for observation when counting. Next, I categorize the domes by size (diameter in meters). I add up all the annual attendance figures I received for each category, and average the total. Then, I multiply that average by the number of domes of that size known to exist, to project an annual attendance for each category. Sum them up, and voila, an estimate of total annual attendance. I also calculate for how much of the projection each category accounts. Here's the tally (columns will align when viewed with a fixed-pitch font): Dome size Responses Visitors Average # Domes Projection Percentage U.S. 21m - up 9 2,792,000 310,222 14 4,343,111 14.1% 18 - 20.9 18 1,932,405 107,355 24 2,576,540 8.3% 15 - 17.9 22 2,068,370 94,016 40 3,760,672 12.2% 12 - 14.9 46 1,614,732 35,102 96 3,369,875 10.9% 9 - 11.9 98 1,717,443 17,524 315 5,520,352 17.9% 6 - 10.9 54 525,897 9,738 336 3,272,248 10.6% 1 - 5.9 38 471,351 12,403 634 7,864,119 25.6% unknown 0 0 0 131 0 0.0% ---- --------- ---- ---------- TOTALS 285 18% 11,122,198 1590 30,706,919 International 21m - up 14 3,467,657 247,689 80 19,815,182 24.1% 18 - 20.9 24 4,047,894 168,662 91 15,348,264 18.7% 15 - 17.9 14 1,361,654 97,261 95 9,239,795 11.2% 12 - 14.9 19 909,138 47,849 137 6,555,363 8.0% 9 - 11.9 15 640,003 42,666 224 9,557,378 11.6% 6 - 8.9 30 760,081 25,336 506 12,820,032 15.6% 1 - 5.9 28 452,100 16,146 532 8,589,900 10.4% unknown 0 0 0 245 0 0.0% ---- --------- ---- ---------- TOTALS 144 8% 11,638,527 1910 81,925,917 So the answer for 8 March 2010 is: Each year 112,632,836 people visit the 3500 planetaria of the world. As always, I ask your assistance in providing numbers: an attendance figure over a 12-month period for each of the domes your institution operates. I'll incorporate the information and publish it periodically here, just as I now have. The best way to respond is to fill out an LNP Dome Theater Compendium Update Form at the Loch Ness Productions Web site: This will allow us to "freshen" the data we have about your theater facilities, and fill in any blank fields. The latest version of this article can be always be found in the Reference Library section of the Loch Ness Productions Web site: And if you have already responded, thanks! >> Mark