Photo of the Week. Storms of spring give way to blue sky.
Astronomy news for the week starting Friday, April 13, 2007.
This is the week of the crescents, crescent Moons that is, waning in the morning sky the early
part of the week, waxing in the
evening during the latter part, the sequence split by the passage
of new Moon on Tuesday, April 17, about the time of sunrise in
North America. Just six hours before new Moon, the Moon will pass perigee,
where it is closest to the Earth, the increased gravitational tug
resulting in especially high and low
tides at the coasts.
The morning of Saturday the 14th finds the waning crescent just to
the east (to the left of and a bit below) Mars. It thus acts as a
nice guide to the currently elusive red planet, whose rising still
closely tracks the onset of dawn. The morning of Monday the 16th
affords the last chance to see an ultrathin crescent glowing in
bright twilight.
Flipping quickly to the evening sky, the first glimpse of the
waxing crescent can be had the evening of Wednesday, the 18th,
again in twilight. The evening of Thursday the 19th be sure to
take a look at an especially nice convening of the crescent and
brilliant
Venus, the Moon somewhat down and to the right of the planet,
not like directions are needed to find either of them. The sight
is enhanced by the Pleiades
star cluster, which will be down and to the right of the Moon, the
three -- Venus, Moon, Pleiades -- all in a row slanting down and to
the right.
Setting ever later, our "evening star" does not now go down until
around 11 PM Daylight Time. Still at the Leo-Cancer border to
the west of Regulus, Saturn, crossing
the meridian in mid-twilight, shifts
steadily toward the Sun. It's a special week
for the ringed planet, as on Thursday the 19th it ceases
retrograde motion and finally begins heading to the east
against the stars and back toward classical Leo. Just a hour after
Venus sets, around midnight Daylight Time,
Jupiter rises still to the northeast of Antares in Scorpius, the rising of the Scorpion now telling us
that summer is really on the way.
If it's spring, we look to Leo,
which in mid-evening stands proudly high to the south. At its
front lies the famed "Sickle" with Regulus on it's south-reaching
handle. Toward the back, at the Lion's tail, is Denebola. The star is the western
anchor of the large "Great
Diamond," whose other stars are Cor Caroli (to the north in Canes Venatici under the Big Dipper's handle), Arcturus in Bootes to the east, and Virgo's Spica to the
south. More or less centered within it is the lovely constellation
and cluster Coma Berenices.
