| Geyser | 1987-07-28 |
|---|---|
| Corporal | 1200 |
| Dog's Leg Spring | 1200 |
| Echinus | 1027 maj, 1430 maj |
| Pearl | 1200 |
| Steamboat | 1200 |
| Vixen | 1200, 1201 |
| Values for Old Faithful Area | 1987-07-28 |
|---|---|
| Astronomical Twilight Begin | 03:59 |
| Nautical Twilight Begin | 04:48 |
| Civil Twilight Begin | 05:31 |
| Sunrise | 06:05 |
| Sunset | 20:53 |
| Civil Twilight End | 21:27 |
| Nautical Twilight End | 22:10 |
| Astronomical Twilight End | 23:00 |
| Moon Illumination | 5.1% |