Tuesday, June 12, 2018

Finding Libra with the help of Jupiter

























The moment of New Moon will occur in approximately fourteen hours from now -- on Wednesday, June 13 at 19:43 Greenwich time, which is 12:43 Pacific time and 15:43 Eastern time.

Star gazing opportunities will be excellent on the night of New Moon (Wednesday, June 13) as well as on the subsequent nights when the moon will be a very thin new crescent which will be visible in the far western sky following sunset.

However, as the moon continues to wax on subsequent nights, the light of the waxing moon will tend to make constellations more difficult to identify -- which means that the next few nights (until about the 18th or 19th of June) will be some of the best times to go out and look for stars, until after full moon on June 28th (after which the moon will begin to wane again, and also to rise later and later in the evening).

Right now is a particularly opportune time to go outside and try to identify the zodiac constellation of Libra, if it is at all possible for you to do so. Libra can be a very challenging constellation to identify, but right now we have some of the best possible assistance for locating Libra, because the enormous planet Jupiter is presently visible immediately adjacent to Libra, pointing the way to the constellation's upper three stars (arranged in a triangle shape).

The star-chart above shows the constellations of the night sky from the perspective of an observer in the northern hemisphere at approximately 35.6 degrees north latitude, and at about 22:40 (or 10:40 pm), facing towards the southern horizon. The horizon is indicated by a purple line, but will of course vary for your specific geographic location and latitude. Note that the image "wraps" the horizon upwards towards the left and right edges of the star-chart, as described in this previous post from earlier this month. 

Towards the center of the image, you can see the glorious constellation of Scorpio, which is presently rising up high enough to clear the horizon with the full length of its sinuous body by about 10:30 pm (depending on your latitude and the terrain in your area). Scorpio is a dazzling sight, and appears much larger when seen "in person" than you might expect based on the diagram in the chart above.

Just ahead of Scorpio in the night sky is the planet Jupiter, unmistakeable as the bright golden-yellow planet crossing the middle of the southern sky (the only brighter object in the sky right now is Venus, which appears well to the west, above the western horizon after sunset, and sinking down below the western horizon by about 10:00 pm, depending on your latitude and local terrain).

Jupiter is conveniently indicating the location of the constellation Libra, the Balance or the Scales, which precedes Scorpio in the motion of the constellations from east to west across the sky, and which is located between Scorpio and Virgo along the ecliptic path. The star-chart above shows Libra's location between Scorpio and Virgo.

The star-chart below zooms-in on Scorpio, Libra and Jupiter. Note how close Jupiter is presently situated next to the westernmost star of the constellation Libra, alpha Librae (named Zubenelgenubi or Zuben Elgenubi, it is actually a binary). This proximity should go a long way towards helping you to trace out the triangular arrangement of the three stars that make up the top section of the constellation:

























Below the triangular "top" of the constellation (which, since Libra is a Balance or Scales, would properly be called the "beam" of the balance, with the top point of the triangle indicating the "knife-edge pivot" of the balancing scale), there are the "arms" of the balance, indicated by a single star on the "right-hand" side of the scales (as seen in the image above, which is to say the western side of the constellation -- all star-charts depicting the point-of-view of an observer in the northern hemisphere), and indicated by two close-together stars in the "left-hand" side of the scales (the side closest to Scorpio, which is to say the eastern side of the constellation Libra).

Below is the same star-chart, this time with yellow arrows added, pointing to each of the stars of the constellation Libra:

























And below is the same star-chart once more, this time without any "connecting lines" drawn in -- the way the stars will appear in the night sky. Can you make out the outline of Libra, using the planet Jupiter to guide you towards the nearby star alpha Librae (or Zuben Elgenubi)?

























With some practice, you should be able to locate the six most-prominent stars of Libra -- the three which make up its triangular crown, and the three which form the "arms" of the balance (from which the "pans" of the balance would be suspended). The dangling arms of the balance have three stars because there are two on one side (the east) and one on the other (the west).

Below is the same view of the stars of Libra without "connecting lines" drawn, but this time the yellow arrows have been added to point out the six most-visible stars of the constellation Libra:

























Can you see how helpful the present location of Jupiter will be, for trying to identify the stars of Libra in the night sky?

Also, look immediately to the left of the indicated stars of Libra in the star-chart above, and see if you can pick out the stars of Scorpio, which come very close to the stars of Libra (especially to the two close-together stars of the left-hand "arm" of Libra -- the arm of Libra on the east side of the constellation itself).

The constellation Libra plays a role in many of the world's Star Myths -- although it does not play a role in nearly as many myths as its brighter neighbors Scorpio and Virgo play in the world's myths. Nevertheless, you can see Libra depicted in artwork associated with the ancient stories of Odysseus slaying the suitors, and of Samson receiving his famous haircut at the instigation of Delilah, in my most-recent Star Myth video entitled "Blueprints in the Stars," in this previous blog post.

I hope that you will be able to go outside and see Jupiter, Libra, Scorpio, and the other constellations of the glorious mid-June sky during the next few nights, if possible. And, I hope that these pointers will help you to successfully locate Libra in the night sky -- perhaps for the first time!

There is no better time to do so, perhaps, than right now -- when Jupiter is pointing the way.