29 January 1997
This set of observations were made on January 29, 1997 (Ls=71.14, De=22.35) by Carlos E. Hernandez (A.L.P.O Mars Recorder) at 06:45 UT (left image, Wratten 23A (light red) filter, CM=131.7) and 07:15 UT (right image, Wratten 38A (blue) and 64 (blue-green) filters, CM=139.0) using an 8-inch (20-cm) f/7.5 Newtonian reflector at 305x.
The red light (Wratten 23A) image on the left exhibits a brilliant (10/10) North Polar Cap (NPC) with a rift visible p. the CM (possibly Rima Borealis). The NPC is apparently surrounded by a dark (3/10) collar consisting of Mare Boreum, Nerigos, Scandia, and Panchaia (from p. to f., respectively). Ceraunius appears as a dusky (4/10) wedge projecting southward from Nerigos p. the CM. The Propontis complex appears dark (3/10) and "comma-shaped" over Arcadia f. the CM. Elysium is visible on the morning, or f., limb as an extremely bright (9/10), semicircular albedo feature with Trivium Charontis-Cerberus I (3/10) Sp. it and Phlegra-Styx (3/10) p. Elysium. Cebrenia appears dark to dusky (3-4/10) north of Elysium. The f. border of Mare Acidalium (3/10) is visible on the terminator, or evening limb, and Nilokeras (4/10) appears to project from its Sf. border connecting to an equally dusky (4/10) Lunae Lacus. Ganges appears dull (5/10) projecting from Lunae Lacus towards the Sp. limb. An extremely bright (9/10) cloud is noted over the Chryse-Xanthe region along the terminator. Amazonis appears dull (5/10). Solis Lacus is visible on the Sp. limb as a dusky (4/10), "star-shaped" albedo feature with three very bright (8/10) border f. and N. of it. This bright region surrounding Solis lacus appeared brightest while using a Wratten 23A (light red) filter which may indicate martian surface activity such as a dust storm. This region bears close scrutiny at this time as well as in the future. Mare Sirenum appears dark (3/10) and thin along an extremely bright (9/10) southern limb haze (SLH) with Araxes projecting from it's p. end over Daedalia. An extremely bright morning limb haze (MLH) is noted as well.
The blue light (Wratten 38A (blue) and 64 (blue-green) filters) image on the right also shows a brilliant NPC surrounded by a thin, dusky (4/10) collar, as described above. An extremely bright evening limb haze (ELH) is noted with a projection over the Chryse -Xanthe region. An extremely bright (9/10) southern limb haze (SLH) is visible connecting to an equally bright morning limb haze (MLH), as well as the ELH. A very bright to extremely bright (8-9/10) strip is noted to extend over Tharsis. The extremely bright (9/10) condensation at it's center may represent an orographic (mountain-associated) cloud adjacent to Ascraeus Mons, especially prominent while employing a W64 filter.
(Legend: N.=north, S.=south, p.=preceding, f.=following, Np.=north-preceding, Nf.=north-following, Sp.=south-preceding, Sf.=south-following)