Night_skies_08-01

Jeff Green | Jan 10, 2008

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A dance of Bright Planets in the Morning Sky.

January continues the nightly spectacle of bright stars and planets that we had in December. The enormous constellation Orion still marches across our southern evening and night time skies with his faithful dogs, Canis Major and Canis Minor following on the heels of the master, the Great Hunter (Orion). The larger canine has the star Sirius, brightest star in the whole sky, to mark his eye – found in a straight line down and to the left from the three stars marking Orion’s Belt. The smaller canine, somewhat behind and above his companion in the sky, has the star Procyon, sixth brightest star in the heavens, to mark his location. Below Sirius, one can easily distinguish the rough shape of a dog in the pattern of bright stars found there, but below Procyon, it is much more difficult to discern the pattern of a dog or any animal. Just try this exercise, but do remember that our ancestors of long ago were more adept at using their active imaginations to “see” life-like shapes and patterns where we may fail to do so. The outline of Orion himself has seven bright stars, all of them often seen even from the light-polluted backyards of many towns and some cities: Betelgeuse and Bellatrix, the orange and reddish beacons of his shoulders, brilliant white Rigel and noticeably fainter Saif marking his knees, and the perfectly straight alignment of the three belt stars that still bear their mediaeval Arabic names, Alnitak, Alnilam, and Mintaka. Less brilliant, but still easily seen from rural areas are the stars marking Orion’s head, his sword below his belt, and both his arms, one holding his shield and the other bearing his club. Below Orion’s Belt, careful observers will take note, as astronomers have done for centuries, of “The Orion Nebula”, a huge region of hydrogen gas where new stars are being born over millions of years. Though easily visible to the unaided eye from rural sites, this nebula reveals several fascinating surprises when seen through a small telescope.

Of the five bright planets, all of them may be seen this month, but in the first week of January most observers will probably see only three of them. Mercury may be easily seen in evening twilight for those who have a good view of the southwestern horizon or make an effort to avoid a location with buildings or trees blocking the horizon in that direction. Begin observing a half-hour after sunset. In the first week of the month it may be so low as to be visible only with binoculars, but after that time, it should be quite easy to see, until about an hour later when it sets. If lucky enough to see it on January 14, remind yourself that on that day this planet is being visited by a spacecraft called Messenger – an event that has not happened in 33 years. Bright and reddish Mars is easily seen in the east during evening twilight amid the stars of the constellation Taurus, the Bull, and its sheer brilliance, greater than any star, even Sirius, makes Mars the dominant evening presence in any moonless sky for the first half of the month. After that, it begins to lose its brilliance, and it fades considerably over the next three months. During the night, as the earth rotates, Mars marches westward, and it can be seen setting in the west during morning twilight. For those who have a telescope, now is the time to see Mars, as it appears larger and with more surface detail than at any other time over the next 8 years. After 9PM each evening, Saturn may be seen rising in the east, and appearing a short distance from Regulus, the brightest star in the constellation Leo, the Lion. That is the constellation within which Saturn appears for the rest of the year. Those who have a telescope and wish to see Saturn’s rings should wait until late in the evening or about midnight when the planet is high in the sky well above the atmospheric turbulence often noticed at lower altitudes at this time of year. This month’s greatest planetary treat is reserved for those who plan to observe the morning sky in the two hours before sunrise. At that time Venus, by far the brightest of the planets, totally dominates the eastern sky. No, it is NOT a UFO! It is still bright enough to follow after sunrise and to see in the daylight sky, if one knows exactly where to look. Finally, Jupiter, the solar system’s largest and second-brightest planet comes into view, but it hesitates and will remain unseen by most people for the first half of January, unless they search with binoculars below Venus in the morning twilight about a half-hour before sunrise. After January 15, Jupiter will appear well below Venus, but it appears moving upward, morning by morning, until by January 31 the two planets are only about one degree apart (the width of a fingernail held at arm’s length). The following morning, February 1, they will appear even closer. Be sure to set the alarm for 6:15AM on the last few days of the month so as not to miss the spectacle of the dance of the two brightest planets. You will likely find yourself choosing to continue watching as the duo’s performance continues well into early February.

Several moon-planet conjunctions are noteworthy this month. In the pre-dawn eastern sky on January 4, the slim crescent moon is to the right of brilliant Venus and the stars of ‘the claw of Scorpius’. On the following morning, the slim crescent is below Venus and Antares, the reddish lucida of the constellation Scorpius. Late on the night of January 17, the gibbous moon passes through the famous star cluster known as the Pleiades, or The Seven Sisters, and it will even move in front of, or ‘occult’, some of those stars. The sudden disappearance and reappearance of those stars is best seen with binoculars. Be patient as you wait for one star after another to disappear and later emerge into view; remember, too, that you are watching, in real time, the orbital motion of the moon. In the late evening of January 19, high in the eastern sky, the almost Full Moon will appear very close to Mars; in fact, from the Arctic the moon will appear briefly in front of Mars. Be sure to hold your hand in front of the moon to eliminate the glare of moonlight and allow you to see the planet. On the night of January 23, the moon appears close to Regulus, brightest star in the constellation Leo the Lion, and the following night, January 24, the moon appears quite close to the planet Saturn.

More information about astronomical observing throughout the year is available in the latest edition of the book, The Beginner’s Observing Guide, now on sale at Sharbot Lake Pharmacy. Good wishes for 2008 to all readers of the column, and remember to cherish and enjoy the beauty of the winter sky!