| Geyser | 1981-09-17 |
|---|---|
| Blue Mud Steam Vent | 1200 |
| Echinus | 1455 |
| Giantess | 1737 |
| Values for Old Faithful Area | 1981-09-17 |
|---|---|
| Astronomical Twilight Begin | 05:25 |
| Nautical Twilight Begin | 06:01 |
| Civil Twilight Begin | 06:35 |
| Sunrise | 07:04 |
| Sunset | 19:30 |
| Civil Twilight End | 19:59 |
| Nautical Twilight End | 20:33 |
| Astronomical Twilight End | 21:09 |
| Moon Illumination | 87.09% |