Photo of the Week. As seen from an Atlantic Ocean
beach, Canis Major's Sirius, the sky's brightest star,
rides high above number two Canopus, the luminary of Carina in Argo. (The
Star of the Week, Chi Carinae, is very faintly visible directly to
the left of Canopus; bright Regor
[Gamma Velorum] is up and farther left.)
Astronomy news for the week starting Friday, April 11, 2008.
The Moon starts off the week nearly at first quarter, the actual
phase reached on Saturday, April 12, about the time of Moonrise
in North America. It then waxes in the
gibbous as it heads towards full phase next week, on Sunday the 20th.
Our companion than takes on a pair of planets and a star. The
night of Friday the 11th, the Moon will make a fine pairing with Mars, passing less than
a degree to the north of the red planet. The Moon will actually
occult Mars as seen from northeastern Canada, Greenland, Iceland
and other points far north. Next up is Regulus, which the Moon passes to
the south of during the day on Tuesday the 15th. Four hours later
the Moon then passes to the south of Saturn. The
Moon will therefore be to the west of the star and planet the night
of Monday the 14th, then to the east of them the following evening.
Only half again as far from the Sun as Earth, Mars falls only
slowly behind us, which will keep the planet in the evening sky
until next autumn, the setting time (now around 2:30 AM Daylight
Time) not changing much from one night, or even week, to the next.
As the sky darkens, find Mars high in the west in central Gemini to the southwest of Castor and Pollux. We now, however, see
something of a transition, as at mid-northern latitudes, Mars sets
in the northwest just as
Jupiter rises in the southeast, the giant planet then
dominating the sky until bright dawn takes it away. As witnessed
by the above lunar passages, Saturn remains securely in Leo to the east of Regulus. The
ringed planet can be found high to the south, transiting just after
the end of evening twilight, and not setting until nearly the commencement of
dawn. As a bit of a coda to the planetary sky, Mercury passes the Sun in superior
conjunction (the other side of the Sun) on Wednesday the 16th as it
prepares for a rather nice appearance in mid-May.
Almost due south of Canis Major's
Sirius, Canopus, the sky's second brightest
star, is visible only from the southern US and points south. It's
the luminary of Carina, the keel of
the Ship of the Argonauts, which
extends to within 20 degrees of the South
Celestial Pole and which contains one of the most massive stars
of the Galaxy, Eta Carinae.
Between Canopus and Sirius lie the stars of Puppis, the Stern of the Ship, which wraps up and to
the east around the Great Dog. If you are too far north to see
Canopus, you might imagine it gliding across the southern horizon.