Photo of the Week. Bright blowing clouds and their
shadows enhance the crisp blue of the sky.
Astronomy news for the week starting Friday, May 18, 2007.
The Moon continues with its waxing
crescent ways, fattening more and more until it passes first quarter on Wednesday the 23rd, at which
point it will enter the waxing gibbous. The
evening of Friday, May 18th, finds the crescent between the star Elnath (Beta Tauri, which joins Taurus to Auriga) and, higher up, the bright stars of Gemini.
The week is then marked by three lunar passages, the grandest of
which will be a close, classical pairing between the crescent and
evening of Saturday the 19th, the two under two degrees (four lunar
diameters) apart. Fine conjunctions like this one do not come
along that often, so set aside some time to watch. The setting is
equally charming, with the Moon and
Venus placed smack in the middle of Gemini, Castor and Pollux seeming to look admiringly
down upon them. And if that is not enough, when the sky darkens a
bit, the nighttime side of the lunar disk will be gently lit with
The other two passages, in which the Moon glides past Saturn and
then Regulus (in Leo), seem to pale in comparison, in
part because of their relative faintness and in part because they
happen during daylight in North America with the Moon quite out of
sight. Nevertheless, take a look the night of Monday the 21st to
see the crescent to the west of Saturn. By the following night it
will have moved to the east of the planet, planting itself between
Saturn and Regulus, while the night after that, it will be to the
east of the star. The Moon actually occults both of them, but not
as generally seen from North America.
Venus finally begins to top out this week, setting as late as it is
going to do so, around 11:45 PM Daylight Time, the difference from
night to night now inconsequential. Though its brilliance
overwhelms the sky (the planet 14 times brighter than the brightest
star), Venus will continue getting marginally brighter for several
more weeks. Only
Jupiter can begin to compare. Watch as the giant planet rises
in the southeast around 9:30 PM (to the northeast of fainter Antares), shortly before the end of
evening twilight. In between Venus and Jupiter is Saturn. In the
western sky as darkness falls, Saturn stays up 'till well after
midnight, not setting until 1:30 AM.
In other news,
Mercury is popping up a bit in the northwest just after
sundown, Mars slowly
separates from the onset of dawn (look for it low in the east), and
retrograding the night of Thursday the 24th.
Ursa Major's Big Dipper is now at its evening best, the seven-
star pattern wonderfully obvious. The Little Dipper is not bad either, the figure rising to
the right of the Pole toward it's bigger brother. Opposite the
pole, far beneath it, are Cassiopeia and Cepheus, which are almost impossible to see without a
fine northern horizon. The southern hemisphere has its glories as
well, as now is the season for the Southern Cross, tucked in beneath bright Centaurus. While facing the South Celestial Pole, to the right are Carina of Argo and dimmer Volans
(the Flying Fish, appropriate to the Ship), while to the left lies
Triangulum Australe, a much larger
counterpart of the northern hemisphere's autumnal Triangulum.