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The Sky This Week, 2014 May 13 - 20

Planets on the move.
MarsMap_GRC_2014_05small.jpg
Cylindrical projection map of Mars
based on observations made April - May 2014

The Moon begins the week in her Full phase, then wanes as she moves into the morning sky.  Last Quarter occurs on the 21st at 8:59 am Eastern Daylight Time.  She starts the week off near golden Saturn, then works her way along the southern reaches of the ecliptic through the heart of the southern summer constellations before venturing into the dim realm of the stars of autumn.

As Luna heads for the morning sky, we still have an opportunity to catch four of the five planets known to the ancients before a reasonable bed-time.  You can still see Venus before dawn, and get a full night’s sleep to boot.

Fleet Mercury is first in view, steadily climbing in the western sky during evening twilight.  You should start looking for him at about 9:00 pm, when he’ll be about 10 degrees above the horizon and about 10 degrees north of due west.  Each succeeding night will find him a bit higher as he climbs toward his greatest elongation on the 25th.  Binoculars are a big help when you first try looking for him, but once you’ve spotted the elusive planet you should be able to easily see him with the naked eye.  By the end of the week he passes between the stars that form the “horns” of Taurus, the Bull.  Mercury will be just three degrees south of the star on the 20th and 21st.

Jupiter will probably grab your attention long before Mercury does, since he becomes visible high in the west within a few minutes of sunset.  If you want to still get a decent look at him in the telescope, the twilight hours will be your best bet.  By 9:30 pm Old Jove is just 30 degrees above the horizon, and the combination of radiant heat from the ground and turbulence in the atmosphere will make gleaning fine details on his distant disc very difficult.  However, his Galilean moons are still easily seen in any telescope, and you can watch their comings and goings until just a few minutes before the planet sets at around midnight. 

Mars has lost a little of his ruddy luster since his opposition a month ago, but the red planet is still easy to spot in the evening sky as he moves to the meridian by 10:00 pm.  He reaches the second stationary point of the current apparition on the 21st, resuming direct eastward motion against the stars afterward.  His disc, now just a tad over 13 arcseconds across, remains a visual observer’s challenge, but a six-inch or larger telescope and moments of steady air will reveal his bright north polar ice cap and subtle dark albedo features.  One of the most prominent of these, dubbed Solis Lacus by early visual observers, will be in view by the end of the week.

I had my first good look at Saturn last week as the ringed planet finally cleared the roof of my neighbor’s house at a decent hour.  As usual, that view was still as wonderful as the first one that I can remember.  For the past several years the planet’s rings have been slowly opening toward our line of sight.  They are now generously tipped in our direction, and despite the planet’s southerly declination still show a wealth of structure in moments of steady seeing.  Saturn is probably the only sight that urban astronomers can easily see that conjures up the concept that space is a very strange place.  On a clear night there is something quite special about seeing this distant world, wrapped in its mysterious rings, surrounded by the tiny pinpoints of its many moons.

As mentioned earlier, you can pack up the telescope and be in bed by 11:00 pm with four planets under your belt.  If you’re up by 5:00 am you can add Venus to your collection.  The dazzling planet is now just about due east in the gathering morning twilight, and you should be able to keep her in view until the Sun crests the horizon.  If you happen to point a telescope her way she will resemble a small gibbous Moon as she wallows in the turbulent air.


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