Astronomy news for the week starting Friday, August 10, 2007.
The Moon plows through its new phase this
week on Sunday, August 12th, perfect timing for the Perseid meteor shower (see
below). You can still spot the thin waning
crescent in eastern dawn the morning of Friday the 10th, and
even on that of Saturday the 11th. Then try for the ultrathin waxing crescent in western twilight the
evening of Monday the 13th. The Moon will then become increasingly
visible as the week progresses and as it approaches first quarter on Monday, August 20.
This week and a bit into next feature a rather unusual quadruple
planetary event that ought to be at looked in its entirety. First, Neptune comes into opposition with the
Sun on Monday the 13th. This most distant major planet is very
slowly
retrograding through Capricornus just to the northwest of Delta and Gamma Capricorni. Though well under
naked-eye visibility, it's not hard to spot in a small telescope or
even good binoculars, providing you have it located on a good star
map. Next up are the two inferior planets,
Venus and
Mercury, both of which rather oddly undergo conjunctions with
the Sun just over two days apart, Mercury passing superior
conjunction (on the other side of the Sun) on Wednesday the 15th,
Venus its long-awaited inferior conjunction (more or less between
us and the Sun) on Friday the 17th. Then just four days later,
Saturn follows with its own solar conjunction. Needless to
say, none of this trio will be visible.
That leaves the planetary sky to
Jupiter and
Mars. The giant planet now transits right at sunset, so that
by the time the sky darkens, you can find it a bit to the
southwest. Look for Antares in
Scorpius to the west of it, and
note the strong color contrast between the yellowish planet and the
red supergiant. Jupiter then sets at local midnight (1 AM
Daylight) just half an hour after Mars rises, beautifully placed
north of the Hyades cluster in
Taurus. Now note the color
similarity between the "red planet" and the red giantAldebaran, which lies in front of
the cluster (but is not a part of it). Pay NO attention to the
"email that won't die" that says Mars will be "as big as the Moon"
in August. It's from the last favorable
opposition in August of 2003, and it was wrong anyway.
Be sure to catch the Perseid
meteor shower the morning of Monday the 13th (the night of Sunday
the 12th), as the annual event is primed for the western
hemisphere. The debris of Comet
Swift-Tuttle, the Perseids (which seem to come from the
constellation Perseus) may offer as
many as 90 meteors per hour.
Just below the curve of Scorpius's
tail, if far enough south you can see the most southerly of the
ancient constellations, Ara, the
Altar, which provides a gateway to southern-hemisphere skies. From
temperate southern latitudes, in the evening you can spot Crux, the Southern Cross, over to the
west, being followed across the sky by Beta and Alpha Centauri, and then by bright Triangulum Australe, the Southern
Triangle.
