41 Satellites Observed without Magnification in Six Nights
Ed Cannon, March 26, 2002
(See also "75 Seen in Nine Nights".)
Many people do not know or believe that artificial Earth satellites can be seen without magnification (i.e., "naked-eye" or "one-power"). This is offered as an example of how many may be seen, even from an area within a fairly large city on moonlit nights. Mike McCants told me long ago that with satellite observing, as with many other things, quality is what matters, not quantity. So, the only point here is to demonstrate that several satellites may be seen without magnification on any given night, and the total number seen can rise quickly over a series of evenings.
The following 41 artificial Earth satellites were observed without magnification from Austin, Texas, USA (most from a pedestrian bridge above a street between two buildings on the campus of the University of Texas at Austin), on the evenings of February 22 through 27, 2002 (local time). During these evenings, the Moon was waxing gibbous to full, and on almost all of them, the sky transparency was excellent, making for a limiting magnitude of perhaps +4.0 stars in spite of the moonlight. (As these were seen from within a city, there were always a lot of artificial light sources around.)
The Deep Space 1 Delta Rocket, NORAD 25510, was seen on five of the six evenings.
| NORAD Desig. Name | Number of evenings seen |
Note(s) |
| 00694 63-047A Atlas Centaur 2 | 4 | tumbling slowly; oldest bright satellite |
| 03019 67-104B Cosmos 185 Rk | 1 | |
| 04814 70-113B Cosmos 389 Rk | 2 | |
| 06155 72-065B OAO 3 Rk | 3 | can sometimes be zero magnitude |
| 08924 76-061B Cosmos 836 Rk | 1 | |
| 10121 77-059B Cosmos 923 Rk | 1 | |
| 10954 78-062B GOES 3 Rk | 1 | |
| 11630 79-099B Cosmos 1145 Rk | 1 | |
| 11682 80-008A Cosmos 1154 | 1 | |
| 11821 80-044A Cosmos 1184 | 1 | |
| 11849 80-051B Meteor 1-30 Rk | 2 | |
| 12155 81-008B Cosmos 1242 Rk | 2 | |
| 12988 81-117B Cosmos 1328 Rk | 2 | |
| 13068 82-013B Cosmos 1340 Rk | 1 | |
| 13771 83-003B Cosmos 1437 Rk | 1 | |
| 15890 85-058B Cosmos 1666 Rk | 2 | |
| 15944 85-069A Cosmos 1674 | 1 | |
| 16102 85-087B Intelsat 512 Rk | 1 | tumble period about 4 sec. |
| 18959 88-020B Cosmos 1933 Rk | 1 | |
| 19649 88-102A Cosmos 1980 | 2 | |
| 20453 90-008B GPS 2-6 Rk | 3 | or NAVSTAR 18 Rk or USA 50 Rk |
| 20510 90-018A Okean 2 | 1 | |
| 21147 91-017A Lacrosse 2 | 2 | |
| 22236 92-080A Cosmos 2221 | 2 | |
| 22237 92-080B Cosmos 2221 Rk | 1 | |
| 22566 93-016B Cosmos 2237 Rk | 1 | |
| 22823 93-061A SPOT 3 | 2 | a single flash on each of two nights |
| 23230 94-056A ETS 6 (Kiku 6) | 1 | 13 one-power flashes; period about 8.4 sec. |
| 23405 94-077B Cosmos 2297 Rk | 3 | |
| 23533 95-015A DMSP B5D2-8 | 1 | a brief flare in bright twilight |
| 23659 95-046C Sich 1 Rk | 1 | |
| 23944 96-039B Apstar 1A Rk | 1 | tumble period about 24 sec.? |
| 24279 96-046C Adeos Rk | 2 | |
| 24903 97-043A Iridium 26 "?" | 1 | flared as predicted by Iridflar |
| 24906 97-043B Iridium 23 | 1 | predicted flare |
| 25063 97-074A TRMM | 3 | |
| 25104 97-082A Iridium 45 | 1 | predicted flare |
| 25105 97-082B Iridium 24 | 3 | flashing, spectacular, period about 9.36 sec. |
| 25510 98-061C DS-1 Rk | 5 | tumbling, period about 35-37 sec. |
| 25577 98-074A Iridium 11 | 1 | predicted flare |
| 25727 99-024A Orion 3 | 4 | occasional spectacular flashes; period about 19 sec. |
Below is a summary of each evening with the objects listed more or less in order of appearance:
2002/Feb/23 UTC ------------------------- 11821 80-044A Cosmos 1184 25510 98-061C DS-1 Rk (a Delta, tumbling, about 35-37 seconds) 13771 83-003B Cosmos 1437 Rk 25063 97-074A TRMM 13068 82-013B Cosmos 1340 Rk 24903 97-043A Iridium 26 "?" (flared as predicted by Iridflar) 04814 70-113B Cosmos 389 Rk 25105 97-082B Iridium 24 (flashing, spectacular) 25727 99-024A Orion 3 (occasional spectacular flashes) 12988 81-117B Cosmos 1328 Rk 11849 80-051B Meteor 1-30 Rk 22237 92-080B Cosmos 2221 Rk 22236 92-080A Cosmos 2221 15890 85-058B Cosmos 1666 Rk 00694 63-047A Atlas Centaur 2 2002/Feb/24 UTC ------------------------- 25105 97-082B Iridium 24 24906 97-043B Iridium 23 (predicted flare) 04814 70-113B Cosmos 389 Rk 15944 85-069A Cosmos 1674 25727 99-024A Orion 3 16102 85-087B Intelsat 512 Rk (tumble period about 4 sec.) 11849 80-051B Meteor 1-30 Rk 06155 72-065B OAO 3 Rk (very bright pass) 20453 90-008B GPS 2-6 Rk (or NAVSTAR 18 Rk or USA 50 Rk) 08924 76-061B Cosmos 836 Rk 25510 98-061C DS-1 Rk 24279 96-046C Adeos Rk 10954 78-062B GOES 3 Rk 00694 63-047A Atlas Centaur 2 2002/Feb/25 UTC (some cloud interference, chat with a neighbor) ------------------------- 25727 99-024A Orion 3 (one flash) 25104 97-082A Iridium 45 (predicted flare) 25510 98-061C DS-1 Rk 19649 88-102A Cosmos 1980 06155 72-065B OAO 3 Rk 2002/Feb/26 UTC ------------------------- 25577 98-074A Iridium 11 (predicted flare) 25510 98-061C DS-1 Rk 25105 97-082B Iridium 24 (flashing, spectacular) 19649 88-102A Cosmos 1980 (a -2 flash, tumbling 30-40 seconds?) 15890 85-058B Cosmos 1666 Rk 22236 92-080A Cosmos 2221 25063 97-074A TRMM 23533 95-015A DMSP B5D2-8 (a brief flare in bright twilight) 11630 79-099B Cosmos 1145 Rk 22823 93-061A SPOT 3 (a single flash) 20453 90-008B GPS 2-6 Rk (or NAVSTAR 18 Rk or USA 50 Rk) 23405 94-077B Cosmos 2297 Rk 24279 96-046C Adeos Rk 00694 63-047A Atlas Centaur 2 2002/Feb/27 UTC ------------------------- 20453 90-008B GPS 2-6 Rk (or NAVSTAR 18 Rk or USA 50 Rk) 23944 96-039B Apstar 1A Rk (another CZ-3, tumble period ~ 24 sec.) 12988 81-117B Cosmos 1328 Rk 22823 93-061A SPOT 3 (a single flash) 06155 72-065B OAO 3 Rk (can sometimes be zero magnitude) 12155 81-008B Cosmos 1242 Rk 20510 90-018A Okean 2 21147 91-017A Lacrosse 2 23405 94-077B Cosmos 2297 Rk 25727 99-024A Orion 3 (one flash) 23230 94-056A ETS 6 (Kiku 6; 13 one-power flashes) 2002/Feb/28 UTC ------------------------- 00694 63-047A Atlas Centaur 2 25063 97-074A TRMM 22566 93-016B Cosmos 2237 Rk 03019 67-104B Cosmos 185 Rk 18959 88-020B Cosmos 1933 Rk 12155 81-008B Cosmos 1242 Rk 23659 95-046C Sich 1 Rk 25510 98-061C DS-1 Rk 11682 80-008A Cosmos 1154 23405 94-077B Cosmos 2297 Rk 10121 77-059B Cosmos 923 Rk 21147 91-017A Lacrosse 2