Skylights featured four times on Earth Science
Picture of the Day: 1
, 2
, 3
, 4
.
Photo of the Week.. The Moon emerges from the
Earth's shadow in the eclipse of May 15, 2003.
Astronomy news for the week starting Friday, May 23, 2003.
The
Moon, having passed its last -- third -- quarter last Thursday
(May 22), fades through its waning
crescent phase during the week, not reaching its new phase
until Friday the 30th. We therefore have one of those weeks in
which none of the "quarterings" of the lunar orbit occur, the new
phase in a sense being "zeroeth quarter," full "second quarter,"
though neither of these terms is in actual use. Toward the middle
of the week, on Tuesday the 27th, Venus
comes into conjunction with its brother "inferior" planet
Mercury ("inferior" meaning that the two the lie closer to the
Sun than we), the best views being the mornings of Tuesday the 27th
and Wednesday, the 28th. If you have a clear eastern horizon, the
slimming crescent Moon will make a fine triangle with the two
planets on the 28th, lying up and to the right of them. The
following morning, on Thursday the 29th, the Moon will be much
lower and thinner, and down and to the left of the planets. All
this action takes place in twilight, as Venus rises just an hour
before sunrise. The Moon actually
takes a bead on Venus, and occults, or passes over it, though out
of sight in the Americas (the event visible only in the eastern
hemisphere).
In the evening sky,
Saturn now sets just as astronomical twilight ends (that is,
when the sky is fully dark, defined as being when the Sun is 18
degrees below the horizon), making the ringed planet increasingly
difficult to see.
Jupiter, on the other hand, has now made its full transition to
evening, setting at local midnight (1 AM Daylight Time). A quarter
hour later, Mars
rises in the southeast, notable by its bright reddish glow. Mars,
now being approached by the Earth, is rather quickly zipping along
to the east relative to the stars, which temporarily delays its
transition to an evening rise time (which takes place June 1).
Watch the red planet now, as it is approaching a "
favorable opposition," and on August 27 will be closer to Earth
than in any time in recorded history (though not by a lot).
If you live very far south, you can see the Southern Cross making its transit across the southern
meridian around 9 PM, followed by Beta then Alpha Centauri, the latter the closest star to the
Earth (all visible only from somewhat south of the 30th parallel).
At about the same position in northern skies lies the Big Dipper, which is fully visible
only to the north of about 30 degrees SOUTH latitude. The famed
"Pointers" of the Dipper, the two front bowl stars, direct the eye
to Polaris. But along the way,
they also point to the tail -- the end star of -- Draco, the Dragon (which winds to
the east between the Big and Little
Dippers), the star known as Giausar, or Lambda Draconis.