| Observer | Johan Warell |
| Date | 1999 April 1 |
| Time (UT) | 03:05 |
| Site | Uppsala University Astronomical Observatory, Sweden |
| Instrument | 16 cm f/12.5 apochromatic refractor, x330 |
| Filter | I.L. |
| Seeing (Ant.) | IV-V |
| Ls | 117.8 deg |
| CML | 28.4 deg |
| Diameter | 14.0" |
| Phase | 0.98 |
| Phase Angle | 18.2 deg |
| P | 38 deg |
| Q | 284 deg |
| Notes | Poor seeing and observing conditions, altitude of Mars 15 degrees. The MLC still yellowish and bright, very extended. No details seen, only rough outlines of albedo features and clouds/hazes. |
Area/Filter I.L. NPC B MLC/MLH M-B Chalce M ELC M Observations made 03:10 UT.