Photo of the Week. Ocean sunrise, the Sun reflecting
off the distant water. See the whole sequence: 2, 3, 4, 5. The oblateness is
caused by refraction in
the Earth's atmosphere; the lower edge of the Sun is refracted
upward more than the upper edge. Irregularities are the result of
atmospheric layering.
Astronomy news for the week starting Friday, April 18, 2008.
Starting out as a fat, waxing gibbous, the
Moon hits its full phase around the time of Moonset the
morning of Sunday, April 20. The night of Saturday the 19th, the
not-quite-full Moon will thus rise just before sunset, while the
following evening, the just-past-full Moon will rise just after
sunset. The rest of the week finds the Moon in the shrinking, waning, gibbous as it heads towards third quarter next
week on Monday the 28th. Almost exactly three days after full
phase, the Moon then passes apogee, where it
is about five percent farther from the Earth than average.
Swinging down through the southern part of the Zodiac, the nearly full Moon will
appear to the south of Virgo's Spica the night of Saturday the 19th.
After passing through Libra, it
then takes on Scorpius, the
celestial Scorpion, passing close to Antares during the daytime on
Wednesday the 23rd. That morning then finds the Moon to the west
of the star, while on the morning of Thursday the 24th, the Moon
will appear to the east of the star.
The evening sky is still graced by Mars, with its
once-abundant water and the still-open possibility of primitive
life, and Saturn, with its
striking ring
system. Mars, transiting the celestial meridian well before sunset,
can now be seen after the end of twilight in the west in central Gemini, where the red planet makes
a fine colorful trio with orangy Pollux and white Castor above it. To the east of
Mars, Saturn resides two zodiacal constellations over, in Leo, tight up against (and to the east
of) Regulus, the planet
transiting the meridian high to the south just as twilight finally
ends. Mars then sets in the northwest around 2 AM Daylight Time,
moments after Jupiter rises
in the southeast, with Saturn setting around 4 AM Daylight. The
remainder of the morning is spent with Jupiter to the northwest of
the classical figure of Sagittarius
as it fades into dawn.
Lood for the
Lyrid meteors the morning of Tuesday the 22nd, though the
bright Moon will blot out most of them.
Though spring is now in full gear, it's hard to let go of the
winter constellations.
At the end of twilight, Orion is way down the western sky.
A look to the north, however, still very nicely reveals pentagon-
shaped Auriga with bright Capella. Ranking number six in
apparent brightness (in part because it is a close double star),
Capella is so far north that it never sets for anyone living above
44 degrees north latitude, which includes the northern tier of US
states and almost all of Canada. On the other hand, below 44
degrees south latitude, it cannot be seen at all (much as Alpha Centauri, the sky's closest
star, is not visible in most of the US).
