SKYLIGHTS
Astronomy news for the week starting Friday, July 16, 1999.
The Moon grows through its waxing crescent early in the week,
passing through first quarter on Tuesday the 20th, thereafter
growing in its gibbous phase, apogee taking place around midnight
the night of Thursday the 22nd. This is an excellent time to view
the Moon with even the smallest of telescopes, the craters and
mountains (which are the rims of huge impact basins) standing out
by throwing long shadows in slanting sunlight. A close look will
reveal mountain peaks just catching the first rays of sunlight at
the sunrise line where daylight meets the dark. The night of the
first quarter, the Moon will be seen to the northeast of
Mars.
The Sun is now seriously catching up to brilliant Venus, which lies
ever lower in western evening twilight. It will be gone in less
than a month as it prepares to pass between us and the Sun. Mars,
however, now well to the east of the star Spica, will be with us
for a long time as it only slowly falls behind the speedier Earth.
But as we lose Venus we gain Jupiter and Saturn, now nicely visible
in the morning sky, coming up at about the time Mars sets.
Early in the week the Moon will not be so bright as to allow
admiration of constellations hardly mentioned. Look halfway
between Albireo (at the foot of the Northern Cross) and Altair (the
southern apex of the Summer Triangle, easy to find with its two
fainter outriding stars). Here find the small row of stars that
make ancient Sagitta, the Arrow, which one myth calls the arrow of
Hercules. Just to the northeast of Altair is a prominent distorted
box that makes Delphinus, the celestial Dolphin. And halfway
between Altair and the Little Milk Dipper of Sagittarius,
recognizable mostly as a bright patch in the Milky Way, is the
pretty modern constellation Scutum, the Shield. Originally "Scutum
Sobiescianum," the figure honors John Sobieski, King of Poland, who
defended his and other lands against invasion in 1683, the only
nationalistic modern constellation to survive to our times. Then
if you have a clear southern horizon, look for the exquisite Corona
Australis, the Southern Crown, an obvious circlet of stars below
Sagittarius, said the be the Archer's crown, and below that, just
skirting the horizon for most northerners, is the obviously modern
Telescopium, the Telescope.
