1996/97 Mars Observation Reports -- # 023--

OAA MARS SECTION

- Additional Reports published in CMO #202 -

25 April 1998

       FRASSATI, Mario (MFr) Crescentino, Italia
             10 Drawings (14 Jan; 19. 23 Feb; 2+, 9, 17 Mar; 1, 13 Apr; 3 May; 15+ June)
                                      20cm Schmidt Cass / 32cm speculum+

       TANGA, Paolo (PTg) Pino Torinese, Italia
             11 Drawings (21 Feb; 11, 12, 13, 26 Mar; 13 Apr; 1 May)  42cm rifrattore 

  We review briefly the drawings chronologically:
  MFr made his first drawing on 13/14 Jan (064°Ls) at ω=229°W in which the north polar cap (npc) was large bounded by a dark band.
  The second by MFr was on 19/20 Feb (080°Ls) at ω=187°W where a large bright white cloud (grande nube bianco brillante) existed evidently near the evening limb.
  On 21/22 Feb (082°Ls), PTg observed at ω=163°W where the Tharsis ridge and Olympus Mons were brighter than the npc, Olympus Mons looking round. Propontis I was clear and dark at the opposite of the dark region including Propontis II.
  On 22/23 Feb (082°Ls) MFr made at ω=223°W: Elysium is small but roundish bright (intensity 0).
  On 02/03 Mar (085°Ls) MFr observed atω=094°W where M Acidalium was near the preceding limb and the evening Chryse is bright (int 1.0) more through W80A.
  On 09/10 Mar (088°Ls) MFr at ω=017°W, M Acidalium was dark and Chryse bright (1.0) in the morning.
  On 10/11 Mar (089°Ls) PTg made a drawing at ω=060°W where Solis L and Tithonius L were evident at the morning side. M Acidalium was in the afternoon and Hyperboreus L was very dark.
  On 12/13 Mar (089°Ls) PTg observed at ω=319°W where Hellas was whitish bright near the evening limb: S Meridiani already inside the disk and M Acidalium and Hyperboreus L were coming in. One hour after, Hellas was still visible. This drawing was made by use of 240× 15cm Newtonian.
  On 13/14 Mar (090°Ls) PTg made a good drawing at ω=342°W where S Sabaus was at the CM: Ismenius L and Oxia Palus were evident while Deuteronilus was faint. An evening mist is seen over Syrtis Mj from the Libya near the limb to Aria through W25. De (φ)=23°N, App.Diam (δ)=14.1". This drawing is cited at page 37 of l'astronomia numero 181 novembre 1997 (in an article by A LEO, G QUARRA & D SARTOCCHI).
  On 17/18 Mar (092°Ls) MFr at ω=299°W: Syrtis Mj seen dark and large together with the east part of S Sabaus.

  After opposition, on 26/27 Mar (096°Ls) PTg made good observations at ω=217°W and at 226°W where Propontis I and the Aetheria dark patch were seen in a proportion. In the latter drawing Syrtis Mj was coming in from dawn.
  On 01/02 Apr (099°Ls) MFr observed at ω=183°W where the morning Elysium region is whitish bright. No Propontis I however.
  On 13/14 Apr (104°Ls) PTg was endowed with good seeing and obtained three drawings: At ω=046°W S Meridiani was still near the evening limb and M Acidalium dark near the CM from which the dark Hyperboreus L is separated. At ω=056°W, S Meridiani disappeared but at the opposite side TANGA caught Ascraeus Mons as a dark stain inside the morning haze.
 At ω=063°W (22:10GMT) he finally saw three dots of the Tharsis Montes whose drawing was cited in the preceding issue #201 p2246 as Fig 6. Seeing was II ( left ) .
  The Observing Note reads "At 22:22 (ω=066°W) I see the three dots, one of them exactly on the limb. This one seems to be connected with the middle spot. While the spot closer to the CM is visible nearly constantly, the other two are detectable only in the moments of more steady seeing. These seem less dark than the former". A whitish patch precedes S Aurorae.
  At the same time on 13/14 Apr at ω=063°W, MFr observed: no details but the morning Tharsis side is largely misty.

  On 01 May (112°Ls) PTg observed at ω=246°W and at 254°W (21:45GMT): In the former, the Atheria dark patch and N Alcyonius were impressively detected and Syrtis Mj was protruding out from the morning mist in a tint of blue. In the latter by the use of W38A (blue), Elysium light but Syrtis Mj invisible. Later at 22:20GMT, Syrtis Mj was considerably inside but still covered by the mist. Notable is that Hellas already light (int 2) near the morning terminator.
  On 03 May (113°Ls) MFr observed at ω=244°W when Syrtis Mj was still near the morning terminator.
  On 15 May (118°Ls) FMr finally observed at ω=188°W: The evening limb light but no marking inside.
  MFr seems to have a tendency to draw the npc larger than the real size.