[Horikawa_J20040328-1100_drw.jpg]
2004/03/28 11h00m(UT)
I= 14.7 II= 60.2
Seeing=6-7/10 Transparency=3/5
・STBの暗斑は昨日の観測よりも濃く明瞭に見える
・NTrZの黒点はIII shadow
・今日からダイヤペークという紙になる、ニューケントよりは表面が荒れていない

[Horikawa_J20040328-1456_drw.jpg]
2004/03/28 14h56m(UT)
I=158.6 II=202.8
Seeing=7/10 Transparency=3/5
・EZsがCM左で白斑状に明るい、後方はSEBn edgeからprojectionが突き出てやや乱れている、EZs/SE
Bn disturbanceの主要部らしい
・EZnにはplume状の明部が見られる
・NEBは概ね二条

[Horikawa_J20040328-1602_drw.jpg]
2004/03/28 16h02m(UT)
I=198.8 II=242.7
Seeing=6/10 Transparency=2/5
・CM右でNEB内に白斑状の明部、新しいriftか?
・EZsはこの経度でも横長の白斑状の明部あり

[Horikawa_J20040328-1550_img.jpg]
2004/03/28 15h50m(UT)
I=191.5 II=235.4 De=-1.5 Dia=43.6
Seeing=6/10 Transparency=2/5
16cm Refl. x143
Philips ToUcam Pro 563 frames composite
≪神奈川県横浜市泉区  堀川邦昭≫

Date (U.T.): Mach 28, 2004
Time (U.T.): 04:25
L1 134.0, L2 181.6, L3 114.9
Instrument: 9-inch (23-cm) F/13.5 Maksutov-Cassegrain
Magnification: 258x and 388x
Filters: None (IL)
Seeing (1-10): 5-6 (moments of 7), Antoniadi (I-V): III
Transparency (1-6): 3-4 (intermittent clouds)

Notes:
South Polar Region (SPR): Appeared dusky to dull (4-5/10) and mottled.
South South Temperate Zone (SSTZ): Appeared shaded (6/10) and thin.
South South Temperate Belt (SSTB): Appeared dusky (4/10) and thin.
South Temperate Zone (STZ): Appeared bright (7/10) and thin. Oval BE
appeared bright (7/10) and surrounded by a dark (3/10) collar towards
the preceding limb.
South Temperate Belt (STB): Appeared dark (3/10) and thin.
South Tropical Zone (STrZ): Appeared bright (7/10) without any other
detail visible within.
South Equatorial Belt (SEB): Appeared dark to dusky (3-4/10) with a
thin, bright (7/10) zone (SEBZ) separating the northern and southern
components.
Equatorial Zone (EZ): Appeared bright (7/10) with dark to dull (3-5/10)
festoon projections (loops) noted within.
North Equatorial Belt (NEB): Appeared dark to dusky (3-4/10) with
bright (7/10) condensations and rifts noted within it. Very dark to
dark (2-3/10) festoon bases were noted along the southern border
(NEBs). A very bright (8/10) bay was noted along the northern border
(NEBn) preceding the CM.
North Tropical Zone (NTrZ): Appears bright (7/10) without any detail
visible within.
North Polar Region (NPR): Appears dusky to dull (4-5/10) with thin
bands and zones noted within. This region also appears mottled.

The following Galilean satellites were observed from preceding to
following; Europa, Callisto, Ganymede and Io.

The best of luck to you and your family and in your own imaging of
Jupiter.
[[Carlos E. Hernandez  South Florida U.S.A ]]

[Bruno Daversin  Cherbourg, France]

Original jpg

At first glance, Jupiter looks like it has a mild case of the measles.
Five spots – one colored white, one blue, and three black – are
scattered across the upper half of the planet. Closer inspection by
NASA's Hubble Space Telescope reveals that these spots are actually a
rare alignment of three of Jupiter's largest moons – Io, Ganymede,
and Callisto – across the planet's face. In this image, the telltale
signatures of this alignment are the shadows [the three black circles]
cast by the moons. Io's shadow is located just above center and to the
left; Ganymede's on the planet's left edge; and Callisto's near the
right edge. Only two of the moons, however, are visible in this image.
Io is the white circle in the center of the image, and Ganymede is the
blue circle at upper right. Callisto is out of the image and to the right.

On Earth, we witness a solar eclipse when our Moon's shadow sweeps across
our planet's face as it passes in front of our Sun. Jupiter, however, has
four moons roughly the same size as Earth's Moon. The shadows of three of
them occasionally sweep simultaneously across Jupiter. The image was taken
March 28, 2004, with Hubble's Near Infrared Camera and Multi-Object
Spectrometer.
Seeing three shadows on Jupiter happens only about once or twice a decade.
Why is this triple eclipse so unique? Io, Ganymede, and Callisto orbit
Jupiter at different rates. Their shadows likewise cross Jupiter's face at
different rates. For example, the outermost moon Callisto orbits the slowest
of the three satellites. Callisto's shadow moves across the planet once for
every 20 shadow crossings of Io. Add the crossing rate of Ganymede's shadow
and the possibility of a triple eclipse becomes even more rare. Viewing the
triple shadows in 2004 was even more special, because two of the moons were
crossing Jupiter's face at the same time as the three shadows.
Jupiter appears in pastel colors in this photo because the observation was
taken in near-infrared light. Astronomers combined images taken in three
near-infrared wavelengths to make this color image. The photo shows sunlight
reflected from Jupiter's clouds. In the near infrared, methane gas in
Jupiter's atmosphere limits the penetration of sunlight, which causes clouds
to appear in different colors depending on their altitude. Studying clouds
in near-infrared light is very useful for scientists studying the layers of
clouds that make up Jupiter's atmosphere. Yellow colors indicate high clouds;
red colors lower clouds; and blue colors even lower clouds in Jupiter's
atmosphere. The green color near the poles comes from a thin haze very high
in the atmosphere. Ganymede's blue color comes from the absorption of water
ice on its surface at longer wavelengths. Io's white color is from light
reflected off bright sulfur compounds on the satellite's surface.
In viewing this rare alignment, astronomers also tested a new imaging
technique. To increase the sharpness of the near-infrared camera images,
astronomers speeded up Hubble's tracking system so that Jupiter traveled
through the telescope's field of view much faster than normal. This technique
allowed scientists to take rapid-fire snapshots of the planet and its moons.
They then combined the images into one single picture to show more details of
the planet and its moons.

[NASA/JPL/Space Science Institute]

ALPO-Japan Latest Jupiter Section