The brilliant planet Jupiter attracts attention even from within brightly lit cities. To the unaided eye, the king of the gods and the largest planet in our solar system appears as a dazzling silvery-white star shining with a steady glow.
Right now, Jupiter rises well above the horizon, to an altitude of nearly 30 degrees in astronomers' parlance, by around 8:45 p.m. local time. (Your fist held at arms length measures roughly 10 degrees. So when we say Jupiter rises to an altitude of 30 degrees, it would appear to be roughly "three fists" above the horizon.)
Altitude is good for telescopic viewing because the planet's reflected sunlight passes through less atmosphere above Earth en route to an eyepiece, which means less distortion. Jupiter reaches the 30-degree height as early as 7:45 p.m. by months end.
"Big Jove" has been called "the amateur astronomers planet." It has the largest apparent disk of any bright object in the sky after the Moon and the Sun. Its dark belts and bright cloud zones with their subtle markings, and of course its four large and bright moons first observed by Galileo in 1610 make Jupiter a perpetual center of interest.
able --> A moderately sized backyard telescope will reveal these moons as pinpricks of light near Jupiter, and one can observe them changing positions from night to night.
Jupiter currently holds the title of the brightest 'evening star,' outshining even Saturn. Look for this dazzling silvery-white object of magnitude -2.6, rising out of the eastern sky shortly after nightfall. The astronomers' magnitude scale uses negative numbers to denote the brightest objects.
Jupiter appears fully three times brighter than its nearest competitor, Sirius, the Dog Star (the brightest real star in the night sky). During the early evening hours of Jan. 18, Jupiter will appear to hover well below the Full Moon as they climb up the east-northeast sky. On the following night (Jan. 19), note how the Moon has shifted to a position well below and to Jupiters left.
Jupiter is at opposition to the Sun on Feb. 2, when it is directly opposite the Sun in respect to Earth. At opposition, Jupiter rises at sunset, stands highest in the south at midnight, and sets at sunup.
Presently, Jupiter can be found within the faint stars of Cancer, the Crab. Sadly, the plague of light pollution is robbing us of our celestial heritage, and poor Cancer is one of the victims. Because it contains no star brighter than 4th magnitude, the Crab is difficult, if not impossible to see under a light-polluted sky.
Jupiter, however, stands out in the field of dim stars.
Cancer is essentially a Greek creation. This creeping creature was sent by Zeuss jealous wife Hera to fatally bite Hercules, Zeuss son from his liaison with Alcmene. The crab arrived just as Hercules was slaying the multiheaded Hydra, one of his assigned 12 "labors."
Cancers bite was no more than a mere annoyance to Hercules, who crushed the Crab under his heel. Infuriated, Hera banished the hapless sea creature to the heavens as one of the most inconspicuous constellations. This story has particular significance now, since Jupiter is in Cancer and Jupiter was the Roman equivalent of Zeus. Furthermore, nearby, directly under the Crab we find the head (and only one head) of the Hydra.
To the Egyptians, Cancer was Scarabaeus, a sacred insect who was charged with rolling the Sun across the sky.
Editor's Note: The Moon will be above Jupiter on the 17th (as seen in the map near the top-right of this page). Look for the Moon closer to Jupiter, and still above the planet, on Saturday, Jan. 18. Then on Sunday, the Moon hovers just below and to the left of Jupiter.
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