Tallying The World's Planetarium Attendance by Mark C. Petersen, Loch Ness Productions A periodic posting, prepared 4 March 2008 "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 14.3% 18 - 20.9 16 1,750,405 109,400 22 2,406,806 7.9% 15 - 17.9 23 2,148,370 93,407 40 3,736,295 12.3% 12 - 14.9 44 1,559,732 35,448 92 3,261,257 10.7% 9 - 11.9 93 1,636,353 17,595 307 5,401,724 17.8% 6 - 10.9 52 510,097 9,809 319 3,129,248 10.3% 1 - 5.9 36 475,438 13,206 602 7,950,379 26.3% unknown 0 0 0 129 0 0.0% ---- --------- ---- ---------- TOTALS 273 18% 10,872,395 1525 30,228,824 International 21m - up 12 3,312,657 276,054 77 21,256,215 26.3% 18 - 20.9 25 3,517,694 140,707 90 12,663,698 15.6% 15 - 17.9 12 1,235,654 102,971 91 9,370,376 11.6% 12 - 14.9 18 796,138 44,229 133 5,882,575 7.2% 9 - 11.9 13 556,872 42,836 212 9,081,297 11.2% 6 - 8.9 29 795,212 27,421 483 13,244,392 16.4% 1 - 5.9 23 420,400 18,278 503 9,193,965 11.3% unknown 0 0 0 227 0 0.0% ---- --------- ---- ---------- TOTALS 132 7% 10,634,627 1816 80,692,520 So the answer for 4 March 2008 is: Each year 110,921,345 people visit the 3341 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