Photo of the Week. A waxing gibbous Moon floats
among the clouds.
Astronomy news for the week starting Friday, May 11, 2007.
The Moon begins our week by waning in its
crescent phase toward new, which it will reach on Wednesday, May
16th. Before and after that invisible phase, it acts as a guide to
two elusive planets. The morning of Saturday the 12th the slimming
crescent will lie to the west of Mars, while by the
following morning it will have flipped to the other side. Then
after new Moon try to find the thin waxing
crescent in the west-northwest during twilight the evening of
Thursday the 17th just above
Mercury, which is an even more difficult target. Looking ahead
(always good to plan ahead), during the following week, the Moon
takes aim on
Venus for a particularly good conjunction the night of Saturday
the 19th, so stay tuned. Looking back, the Moon also encounters Uranus, the
crescent passing north of it on Friday the 11th. The day before
new, the Moon is once again at perigee,
allowing those on the coasts to enjoy especially high and low
tides.
Dominating western evening skies, Venus's show is now close to its
peak. Though still setting ever later, a bit after 11:30 PM
Daylight Time, the night-to-night difference is getting less as the
planet approaches its maximum elongation in early June. Even then,
it will continue to get brighter until early July as it gets ever
closer to Earth. Sandwiched between Venus and the north-south
celestial meridian, find
Saturn. While brighter than all but the most luminous stars
(if a star, it would now rank
ninth), it is still only 1/70 Venus's brilliance, the result of the
latter planet's proximity to us.
Well before Saturn sets at 2 AM,
Jupiter steals the show as it makes something of a transition
to evening by rising just as twilight ends, around 10 PM. It then
transits the meridian half an hour after Saturn sets. Look for the
star Antares in Scorpius to the southwest of the giant
planet. Particularly note the color contrast, Jupiter a creamy
yellow-white, Antares reddish-orange (the star a "red supergiant"). In
the morning, Mars ever so slowly begins to break away from dawn,
rising in the east about half an hour before morning twilight
commences.
While Saturn lies in between Cancer
and Leo, we tend to refer it to
much brighter Leo (to the east of the planet) rather than to dim
Cancer (to the west). Best known for its Beehive Cluster (a pretty sight in binoculars), were
Cancer not along the ecliptic
path, it might never have made it as a constellation at all. Farther west,
northwest really, in the early evening you can still admire bright
Castor and Pollux in Gemini, which appear to look down upon us like a pair
of celestial eyes.
