| Geyser | 1977-07-23 |
|---|---|
| Echinus | 0945, 1045, 1429, 1608 |
| Emerald Spring | 1200 |
| Little Whirligig | 0840, 1240 |
| Whirligig | 1320 A |
| Values for Old Faithful Area | 1977-07-23 |
|---|---|
| Astronomical Twilight Begin | 03:50 |
| Nautical Twilight Begin | 04:42 |
| Civil Twilight Begin | 05:26 |
| Sunrise | 06:00 |
| Sunset | 20:58 |
| Civil Twilight End | 21:33 |
| Nautical Twilight End | 22:17 |
| Astronomical Twilight End | 23:09 |
| Moon Illumination | 43.73% |