| Geyser | 1983-10-21 |
|---|---|
| Mercury | 1748, 1854, 2216 |
| Values for Old Faithful Area | 1983-10-21 |
|---|---|
| Astronomical Twilight Begin | 06:08 |
| Nautical Twilight Begin | 06:42 |
| Civil Twilight Begin | 07:16 |
| Sunrise | 07:45 |
| Sunset | 18:30 |
| Civil Twilight End | 18:59 |
| Nautical Twilight End | 19:33 |
| Astronomical Twilight End | 20:07 |
| Moon Illumination | 99.52% |