| Geyser | 1977-08-19 |
|---|---|
| Arsenic | 1800 |
| Congress Pool | 1800 |
| Echinus | 1207 |
| Little Whirligig | 1345 A, 1610 |
| Pequito | 1800 |
| Whirligig | 0830 ie, 1503, 1830 |
| Values for Old Faithful Area | 1977-08-19 |
|---|---|
| Astronomical Twilight Begin | 04:40 |
| Nautical Twilight Begin | 05:21 |
| Civil Twilight Begin | 06:00 |
| Sunrise | 06:31 |
| Sunset | 20:22 |
| Civil Twilight End | 20:53 |
| Nautical Twilight End | 21:31 |
| Astronomical Twilight End | 22:13 |
| Moon Illumination | 20.53% |