Photo of the Week. Yet another orange sunset...a
different view of this one.
Astronomy news for the week starting Friday, April 2, 2010.
Skylights now resumes its normal weekly schedule.
We start the week with the Moon in its waning gibbous phase as it heads toward third quarter the
morning of Tuesday, April 6, with the Moon nicely up and to the
south around dawn, making for a very nice sight. It then will wane in the crescent, new Moon not achieved
until the middle of next week. The only planetary encounter -- and
hardly a dramatic one -- is with Neptune the
evening of Friday the 9th. The day before, the Moon goes through
apogee, where
it is farthest from Earth in its monthly round.
This week is highlighted by the extremes of the planetary system.
Mercury, the
innermost of the gang, averaging just 40 percent Earth's distance
from the Sun, passes
its greatest eastern elongation on Thursday the 8th, when it will
be nicely visible in western evening twilight and very close to
much brighter Venus, the two in
conjunction near the beginning of our week. Both set as the end of
twilight brings full night to the darkening sky. It's a treat to
be able to see them together. And at the other end of the
planetary system is dim Pluto, which enters
retrograde motion (westerly against the stars) in northern Sagittarius, on Tuesday the 6th.
Traditionally the "last planet," averaging 40 times Earth's
distance from the Sun (but given its eccentric orbit, currently
closer to 30), Pluto is more a member of the "Kuiper Belt," an
extensive zone of orbiting debris that lies beyond Neptune.
For easier visibility, we still have Mars
and Saturn. The
red planet now lies just west of the meridian (the sky's north-south line) as
the sky darkens. Still in Cancer
to the northwest of the Beehive
Cluster, it sets around 4 AM daylight time. Saturn, to the
east of Mars (and still just to the northeast of the Autumnal Equinox in Virgo), transits around midnight and
does not set until sunrise lights the sky.
South of Mars lies the distorted circle that makes the head of Hydra, the Water Serpent. A dark
sky and a clear southern horizon will show the figure snaking to
the south of Leo and then Saturn,
this longest of celestial constellations not ending until it
makes it to the southeast of Spica.
