Skylights featured three times on Earth Science
Picture of the Day: 1
Photo of the Week.. Remembering Cassiopeia as her "W" glides down the northwestern sky
Astronomy news for the week starting Friday, April 29, 2005.
While the week begins with the Moon technically in its waning
gibbous phase, it will quickly move on to waning crescent as it passes its third
quarter the night of Saturday, April 30, roughly around the
time of its rising in North America. The night of the 30th, May
Day Eve, is an astronomical event, a "cross-quarter day," when we
are half way through spring to summer (much like Groundhog Day is
halfway through winter to spring).
As the Moon descends the early morning sky, the crescent
continuously narrowing, it takes on four planets and an asteroid.
On Sunday, May 1, the Moon will (during daylight) pass 5 degrees
Neptune, and then almost exactly 24 hours later will pass 3
degrees to the south of Mars. The morning of Monday the 2nd
therefore finds the Moon to the west of Mars, while the following
morning (Tuesday the 3rd) the Moon will be to the east of the red
planet, which has passed into Aquarius and now rises around 3:15 AM Daylight Time.
That same morning, the Moon glides 3 degrees south of
Uranus, and on the morning of Friday the 6th, 3 degrees to the
Mercury, perhaps allowing you to find the little planet, which
will be near-lost to twilight. The day before, the Moon will
occult, or pass over, the asteroid Juno (the third one discovered), the event however
not visible from anywhere in North America.
That leaves the sky to the stars,
and Saturn, and a meteor
shower. Saturn, in Gemini
and in the northwest as the sky darkens, now sets just after 1 AM
Daylight Time, while Jupiter (in Virgo) climbs the southeastern sky in evening and
crosses the meridian to the south around 11 PM. Retrograding to the west, the increasing separation between
Jupiter and Spica has been quite
obvious. You might also try to find Venus, which will be hiding in
the west-northwest as the sky darkens.
One of the better meteor showers of the year, the Eta Aquarids,
runs through the week and peaks on May 5. For best results, look
in the morning before dawn. The shower, from the debris of
Halley's Comet, typically produces 30 or so meteors a minute
that seem to come out of the constellation Aquarius. We pass near
the orbit of the little particles again in October, when they
produce the Orionid shower.
As we move deeper into spring, the ship Argo sails to the west into the sunset. The eastern-
most section, Vela (the Sails), is
just past the meridian in the southeast as the sky darkens, and
just above the horizon. As the ship disappears, it is replaced by
the stars of northern Centaurus
and then by Lupus (the Wolf) and
magnificent Scorpius, all of which
ride low above the southern horizon for those in mid-latitude
America and southern Canada.