| Geyser | 1977-08-28 |
|---|---|
| Echinus | 0920, 1022, 1221, 1515, 1617 |
| Ledge | 1200 |
| Little Whirligig | 1437 |
| Splutter Pot | 1030 |
| Whirligig | 1030, 1446 |
| Values for Old Faithful Area | 1977-08-28 |
|---|---|
| Astronomical Twilight Begin | 04:55 |
| Nautical Twilight Begin | 05:34 |
| Civil Twilight Begin | 06:11 |
| Sunrise | 06:41 |
| Sunset | 20:07 |
| Civil Twilight End | 20:37 |
| Nautical Twilight End | 21:14 |
| Astronomical Twilight End | 21:53 |
| Moon Illumination | 99.55% |