| Geyser | 1981-09-07 |
|---|---|
| Arsenic | 1040, 1554 |
| Bear Den | 1430 |
| Echinus | 1008, 1049, 1542, 1749, 1829 |
| Graceful | 1148, 1237, 1417, 1558, 1653 |
| Whirligig | 1039:04, 1223, 1412, 1701 |
| Values for Old Faithful Area | 1981-09-07 |
|---|---|
| Astronomical Twilight Begin | 05:11 |
| Nautical Twilight Begin | 05:48 |
| Civil Twilight Begin | 06:23 |
| Sunrise | 06:53 |
| Sunset | 19:49 |
| Civil Twilight End | 20:18 |
| Nautical Twilight End | 20:53 |
| Astronomical Twilight End | 21:30 |
| Moon Illumination | 56.56% |