We bid farewell to Orion and his retinue of encircling winter constellations that are now loitering in the western evening sky.     Before month’s end, we’ll lose Orion to the dusk, just as we have already lost Taurus and the Pleiades.    Of course, Orion and the other prominent winter constellations will return to our pre-dawn eastern skies by mid to late summer.

 

Leo the Lion: a prominent constellation in mid May. (Images: Starrynight.com)

​

Occupying center stage in our evening sky tonight is Leo the Lion.  Consisting of a triangular hind quarter attached to a sickle-shape that resembles a backward question mark, Leo represents the Nemean Lion that Hercules slew as part of his twelve labors.    As Leo is one of those beautiful constellations that actually resemble its namesake, it has been depicted as a lion by many cultures throughout the last five thousand years.   Some art historians even speculate that Leo’s stars might have been imprinted on cave paintings in France dating back more than 20,000 years.

 

South of Leo the Lion we observe the brilliant planet Jupiter.    Brighter even than Sirius, the night sky’s brightest star, Jupiter remains the brightest object visible tonight just after dark.   However, soon to follow is Mars, which rises at 9:24 p.m.

Mars will be at opposition on May 22.  On this date, Earth will pass between Mars and the Sun.  We call this configuration an “opposition” because Mars and the Sun appear in opposite parts of the sky.     Any superior planet, defined as a planet farther from the Sun than Earth, will be closest to Earth around opposition.    This time, however, Mars reaches this point of least distance on May 30^th, when it will be 47 million miles from our planet.

​Oppositions of superior planets occur when Earth passes between the planet and the Sun. The graphic above shows the positions of Mars and Earth relative to the Sun.   (Image: Curtrenz.com.)

Due to this close proximity, Mars will almost be as bright as Jupiter by mid-month.  Mars’s crimson hue, caused by a surface literally coated with rust –or iron oxide, makes it particularly distinct.  Although, Mars currently resides in the constellation Scorpius and is close to its alpha star, Antares.  Antares is a red supergiant star that actually exhibits a reddish color in our sky.  For this reason, it was named “Antares,” meaning “rival to Mars.”    Not much of a rivalry, however, as Mars is presently 15 times brighter than Antares.

 

Following in Mars’ wake is Saturn, which rises at 9:51 p.m. this evening.   This highly celebrated Lord of the Rings planet will reach opposition on June 3^rd.      Unfortunately, its magnificent ring system is not visible to the unaided eye.  However, one can resolve the rings even by observing Saturn through binoculars.   Galileo first saw the rings through his telescope, which was less powerful even than the weakest binoculars currently available on the market.    He perceived the rings as knobs on either side of Saturn, which led him to describe Saturn as the planet “with ears.” For all his cleverness, Galileo never discovered the rings’ true character.  

Watch Saturn through your own binoculars and you can see these “ears” for yourself.     Saturn also appears to occupy the constellation Scorpius, and will remain within Scorpius until February 2017.         Even at opposition, this sixth world will still be 15 times dimmer than Mars as Saturn will still be 838 million miles from Earth at this time. 

 

The Moon was new on May 6th, which started lunation cycle 1155.   On that date, 1154 lunar cycles have been completed since the New Moon on January 17, 1923.     This date was chosen because 1923 was the year that British astronomer and mathematician Ernest Brown introduced his famous lunar theory.   A lunar theory is designed to model the moon's motions and predict future positions. 

The moon will be at first quarter on May 13^th; full on May 21^st and at last quarter on May 29^th.