Photo of the Week. Planets do move! Jupiter is seen
in retrograde between October 1988 and January 1989 against the
background of Taurus. The
identical pictures were taken from town and a dark mountain top,
and starkly show what we have lost through light pollution.
(This pair of images has been added to the Planetary Movement page.)
Astronomy news for the week starting Friday, March 7, 2008.
NOTE: Daylight
Savings Time begins on Sunday, March 9, after which add one hour to the
times below.
We begin our week right on the date of the new Moon, Friday, March 7, which invisibly takes place
around noon in North America. Our first glimpse of the growing crescent will then be in twilight on
the evening of the following day, Saturday the 8th. Two days
later, the Moon passes perigee, where
it is closest to the
Earth. The whole week then belongs to the waxing crescent, as
the Moon will not reach first quarter until
after moonset the morning of Friday the 14th. With the Sun just
shy of the Vernal Equinox in Pisces, this first quarter will be
just short of the Summer Solstice.
The tilt and orientation of the lunar orbit is such that the night
of Thursday the 13th, the not-quite quarter Moon will be north of the
ecliptic, and as it crosses
the meridian about as high as
possible.
In the morning sky,
Mercury and
Venus still do their dance, though they are now almost
impossible to see in dawn's light. On Saturday the 8th, Mercury
passes just south of Neptune, while Neptune's brother planet
Uranus passes conjunction with the Sun. That leaves the
morning for Jupiter, which rises around 3:30 AM just to the northeast
of the Little Milk Dipper of Sagittarius and to the east of the Winter Solstice. Now working its way
to the east and slightly north, the planet will reverse its
direction in about two months as the Earth prepares to swing between
it and the Sun.
The evening sky holds a bit more promise.
Mars first glimmers in twilight high on the celestial meridian
just over the border into Gemini
from Taurus and just under three
degrees to the north of the Summer Solstice, close to opposite
Jupiter's position. With us most of the night, it does not set
until 2:30 AM, an hour before Jupiter rises. Finally, Saturn adds additional luster to Leo. Just to the east of Regulus, the ringed planet is well
up in the east at twilight, crosses the meridian half an hour
before midnight, and is then with us until the stars and planets
fade away under the relentless onset of dawn.
'Tis Gemini season, about the best
time for viewing the most northerly constellation of the Zodiac as it passes high across the
sky in early evening. Look particularly for its two brightest
stars: first magnitude orange Pollux, the brighter and more
southerly, and the brightest of the second magnitude stars, Castor, which the telescope (and
spectroscopy) show to be not single, but sextuple.
