| Geyser | 1977-08-21 |
|---|---|
| Constant | 1232, 1250, 1437 |
| Echinus | 1145, 1238, 1612 |
| Little Whirligig | 1250 |
| Orby | 0950 |
| Pinwheel | 1800 |
| Porkchop | 0950 |
| Whirligig | 0803, 1430, 1534 |
| Values for Old Faithful Area | 1977-08-21 |
|---|---|
| Astronomical Twilight Begin | 04:44 |
| Nautical Twilight Begin | 05:24 |
| Civil Twilight Begin | 06:02 |
| Sunrise | 06:33 |
| Sunset | 20:19 |
| Civil Twilight End | 20:50 |
| Nautical Twilight End | 21:27 |
| Astronomical Twilight End | 22:08 |
| Moon Illumination | 41.1% |