Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. Anvilling thunderheads bring
promise of rain below.
Astronomy news for the week starting Friday, May 28, 2004.
The Moon passes through its full
phase this week on the night of Wednesday June 2, shortly
before midnight in North America as the Moon approaches the
meridian to the south. With the Sun getting farther and farther
north of the equator, the full Moon -- always opposite the Sun --
is getting farther and farther south. This month it appears in Scorpius, just to the west of the Winter Solstice (which is within the
confines of the next constellation over to the east, Sagittarius), and is appropriately
called the "Rose Moon" or "Flower Moon." Only 9 hours after the
Moon passes full, it goes through perigee,
where it is closest to the Earth, the combination bringing
especially high
tides to the coasts (as the height of a shore tide depends on
the combination of lunar and solar tides, which are aligned, and on
the distances to the bodies, which affect their gravitational
effects on the Earth.)
The evening configuration of the planets changes constantly as they
move progressively to the west at different paces.
Venus, ruler of the western sky for so long, is sinking
quickly, and as June begins is nearly invisible close to the
horizon as it prepares to swing between us and the Sun for the
"great event," a
transit across the solar disk on June 8, the first one since
1882. The orbit of Venus is tilted by a bit over three degrees
relative to Earth's orbit. Usually, as Venus passes inferior
conjunction with the Sun (between us and the Sun), it goes above or
below the solar disk. Only on the rare instances when the planet
is near crossing the ecliptic (at a "node") during inferior
conjunction do we get a transit. Transits come in pairs 8 years
apart separated by 243 years (the next one in 2012).
Unfortunately, North America gets a poor view. Those in central
and eastern North America see the Sun rise with the transit in
progress, while those in the west see it not at all. Venus will
appear as a small black disk set against the brilliant Sun. This is NOT a
naked eye event, and may be viewed telescopically ONLY with
professionally made filters properly used, or by
projection.
Mars
and
Saturn, together in central Gemini, follow Venus, both setting less than an hour
after twilight ends. That leaves the celestial stage to
Jupiter, which in early evening stands high to the south in Leo, the giant planet not setting
until after 1:30 AM Daylight Time.
Comet
LINEAR is near its greatest height in evening twilight in the
west southwest, while Comet NEAT is higher and approaching Ursa Major. You will need binoculars to
see them.
If Leo is the traditional harbinger of northern spring, Bootes (the Herdsman), with brilliant
Arcturus, must be second. The
large constellation stretches from near the handle of the Big Dipper all the way down to only
8 degrees from the celestial equator, as it rises looking like a
kite on its side. Directly to the east of it lies one of the
prettier constellations of the sky, Corona Borealis, the Northern Crown.
