Photo of the Week. Clearing skies follow the rain.
Astronomy news for the week starting Friday, January 16, 2009.
Skylights now resumes its normal weekly schedule.
Which starts with the Moon just barely still in its waning gibbous phase as it prepares to go
through third quarter on the night
Saturday, January 17. It thereafter swings into the waning crescent. The morning of Wednesday
the 21st, you can see the crescent approaching Antares in Scorpius, the Moon actually occulting the planet as
seen from southern parts of the world. At the end of the week, the
slimming crescent then passes through
apogee, where it is farthest from the
Earth.
Our early evening sky now pretty much belongs to Venus. Jupiter is lost to twilight, and Mercury passes inferior
conjunction with the Sun on Tuesday the 20th,
whence it becomes a morning planet. But Venus, setting ever later
and getting ever brighter, is enough for now. Not dropping below
the horizon until around 9 PM, the planet far outshines even the
brightest star, will cast shadows in a dark location, and is
visible in full daylight. Having passed its greatest elongation,
where it is at the tangent point in its orbit as seen from Earth,
through the telescope Venus now presents itself as a crescent that
looks like a featureless Moon, the planet perpetually covered with
bright reflective clouds. Which are made not of water like ours,
but of sulfuric acid.
Once Venus sets, we then have only a few minutes wait until
Saturn (now going
retrograde, or westerly, in southeastern Leo) climbs upward. The ringed planet now presents a
fine morning sight as it transits the meridian to the south around 3:30 AM.
As January progresses, Perseus
dominates the early-evening near-overhead sky. To the west of the
Hero find the strings of stars that make Andromeda, to the east of him the striking pentagon of
Auriga, the Charioteer. A line
dropped to the south from Perseus's bright stars passes between Aries to the west and Taurus to the east. Far to the
south, to the west of mighty Orion, runs the stream of Eridanus, the River, which ends at Achernar, the star lost for
northerners below the southern horizon.
