You are here: Home USNO News, Tours & Events Sky This Week The Sky This Week, 2018 November 20 - 27

The Sky This Week, 2018 November 20 - 27

Enter the Hunter, and celebrating the Cornucopia.
Orion from the Front Range, near Boulder, Colorado, 2017 March 7.
Orion from the Front Range, near Boulder, Colorado, 2017 March 7.
with a Canon EOS Rebel T2i DSLR. 30-second exposure, 24mm @ f/3.5, ISO 3200.

The Moon brightens the sky this Thanksgiving week as she climbs toward the northern reaches of the ecliptic.  Full Moon occurs on the 23rd at 12:39 am Eastern Standard Time.  November’s Full Moon is popularly known as the Frosty Moon or Beaver Moon, the latter name deriving from the frenzied activities of these animals as they make ready for the winter’s hibernation.  Luna climbs from the relatively obscure autumnal constellations to cross through the middle of the Great Winter Circle.  Look for the rising nearly-new Moon near the bright star Aldebaran on the evening of the 23rd.  

The Full Moon washes out the faint stars of the autumn constellations, but if you wait up until the later evening hours things will get better as the bright stars of winter take their place in the eastern sky.  You should have no trouble spotting Orion, perhaps the most distinctive constellation in the sky as the midnight hour approaches.  Orion straddles the celestial equator, so parts of him are visible from every part of the planet.  Thanks to this prominent position and his distinctive “belt stars” this star pattern has been a fixture in the sky-lore of just about every culture that has inhabited the planet.  In almost all of these legends Orion personifies an important warrior figure, god, or demi-god.  Some of the oldest depictions of him identify him with Osiris, the ancient Egyptian god of the underworld, who in turn personified the souls of the dead pharaohs in funerary rites.  Known to the Egyptians as “Sahu”, he is depicted on temple walls followed by “Sothis”, the bright star Sirius, which was tied to the cult of the goddess Isis.  Surrounding Orion is a large circle of bright stars which form a large asterism known as the Great Winter Circle.  Of the 25 brightest stars in the sky, nine of them lie within the bounds of the Circle.  

One of these, the bright yellow star Capella, approaches the zenith as midnight passes.  Capella is the third-brightest star in the northern sky and sixth-brightest overall.  It is the lead star in the constellation of Auriga, the Charioteer.  The name “Capella” means “she-goat” in Latin, and the star commemorates Amalthea, the goat that nursed the infant Zeus in Greek mythology.  In one variation of this myth Zeus broke off one of Amalthea’s horns, from which sprang whatever the horn’s viewer desired.  The horn became widely known as the Cornucopia, or Horn of Plenty.  Capella is thus an appropriate marker for the annual celebration of Thanksgiving, beaming down from high in the sky to remind us of the bounties we enjoy here on Earth.

The early evening sky is still hosting two bright planets, Saturn and Mars.  Saturn may still be glimpsed low in the southwestern sky at dusk, and hangs just six degrees above the horizon as twilight ends.  He sets shortly after 7:00 pm. 

Mars crosses the meridian at the end of evening twilight and continues his trek across the dim constellations of the autumn sky.  He is currently moving through the stars of Aquarius, the Water-Bearer, and he remains the brightest object in this part of the sky.  Although his telescopic appearance is now little more than a bright pink-hued dot, take some time to focus your attention on him on the 26th.  On that date, at around noon Pacific Standard Time (3:00 pm EST) the Mars InSight space probe is scheduled to land on the red planet in an area known as Elysium Planitia.  Following an entry into Mars’ thin atmosphere, the probe will undergo “six minutes of terror” as it decelerates from some 13,000 miles per hour to a gentle touchdown on the planet’s dusty surface.  The stationary lander will attempt to drill some 5 meters (16 feet) into the surface to measure the planet’s internal heat flow.

Venus greets early risers in the pre-dawn sky.  The dazzling planet has sprung from the horizon in spectacular fashion over the past few weeks, and is currently shining at close to her greatest brilliance.  You’ll find her in the vicinity of the bright star Spica for the duration of the week.

USNO Master Clock Time
Javascript must be Enabled