From Richard W SCHMUDE Jr
@. . . . . . . . .Congratulations to you and other
Japanese observers on the discovery of a major dust storm on Mars.
My photoelectric magnitude measurements
indicate that between the MARTIAN longitudes of 250 and 310 degrees W, Mars has
gotten brighter in Johnson B, V, R and I filter. The resulting brightness
increases (in magnitudes) for each filter are: B- (0.18+/-0.03), V-
(0.32+/-0.02), R- (0.35+/-0.03), and I- (0.25+/-0.03). The B-V and B-R color
indexes increased by 0.14+/-0.04 and 0.17+/-0.04 magnitude respectively as a
result of the dust; these numbers show that Mars 14-17% redder. It must be
pointed out that Mars is quite dark between 250 and 310 degrees W and that the
dust may not have the same effect at other Martian longitudes. The geometrical
albedo of Mars in the V filter was measured to be 0.20 during July 17~19 2001;
the normal albedo is 0.15.
(21 July
2001)
Richard SCHMUDE Jr (GA,
SCHMUDE@falcon.gdn.peachnet.edu