Skylights featured three times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. Winter sunrise glory; see a close-up.
Astronomy news for the week starting Friday, April 8, 2005.
We begin the week on Friday April 8 with the new Moon. By the
evening of Saturday the 9th you might find the slim crescent in western twilight.
Over the week it will wax through crescent to first quarter, the phase reached on
Saturday the 16th, which is next week's territory.
At new, the Moon is "between" us and the Sun. The lunar orbit, however,
is tilted by five degrees, so the Moon usually passes to the north
or south of the Sun instead of directly across it. On Friday the
8th, however, the Moon will indeed pass over the Sun to give us a
solar eclipse. The eclipse path, where the Moon is
seen exactly in front of the Sun, runs from just east of New
Zealand, across the south Pacific Ocean, and then into northern
South America. It's an odd one.
Since the Moon is rather near apogee, its farthest point from the
Earth, the eclipse starts as annular (the Moon not quite fitting
over the Sun and leaving an annulus of sunlight), then goes to
total, and then back to annular. The southern US and Mexico will
see a partial eclipse, visible south of a line from New York
through central Illinois to
San Diego. The exact times depend on location. Starting times
range from about 5 PM Central Daylight Time near the northern limit
to 4:30 PM in the far southern US. (Add an hour for EDT, subtract
two for PDT). If you are "in the zone," do NOT look directly, as
the Sun is far too bright. Instead, project sunlight through a
pinhole onto a piece of paper and view the image that way (do NOT
look through the pinhole!).
In less exciting news, Mars
passes conjunction with Neptune (Mars 1.2 degrees to the south) on Tuesday
the 12th. In Capricornus, Mars
rises marginally earlier each morning, now about 4 AM (Daylight).
Much better is the evening with Saturn
(in Gemini) high in the west as
the sky darkens and much brighter Jupiter to the
southeast in Virgo, Jupiter
transiting the meridian to the south about 12:30 AM Daylight Time.
The sky's north rotation pole is
rounded by two famed constellations, Ursa Major (the Great Bear) and Cassiopeia (the Queen), the former now in ascendancy in
early evening. Counterparts in the far southern hemisphere are Crux (the Southern Cross), the bright
stars of Centaurus (including Alpha Centauri, the closest star
to the Earth), and following behind, much lesser known Triangulum Australe, the Southern
Triangle, an equilateral triangle of stars much larger than its
northern mate, Triangulum (the
Triangle), which is seen by northerners to rise in autumn evenings
below Andromeda.
