Skywatch February 2005

by Julene M Johnson

Planet Visibility
Mars is visible in morning sky the entire month of February. Saturn is visible as an evening star and through most of the night during the month of February. Jupiter joins him from around 10:00 p.m. until dawn. Venus is visible in the morning until February 19th when she leaves the morning sky. She will return as an evening planet in May. You may be able to catch a glimpse of Mercury on February 1st, after which he leaves the morning sky as he moves behind the Sun from our geocentric point of view to form a superior conjunction with the Sun. He will return as an evening planet on February 25th as he comes out from behind the Sun. Venus moves much slower through the zodiac then Mercury and therefore she disappears from our view longer than Mercury as she too moves behind the Sun. Venusí superior conjunction with the Sun occurs at the end of March.

Moon Data
February begins with the Moon in her disseminating phase. The Third Quarter Moon occurs on the 2nd at 2:27 a.m. EST when the Moon perfects a waning square to the Sun. Her left or eastern side will be illuminated. Moonrise occurs at night around 1:30 a.m. Local Time and Moonset occurs in the day around 11:00 a.m. LT. On the 7th at 5:12 p.m. EST, she reaches perigee, her closest distance to Earth of 222,802 miles. The Moon conjuncts the Sun on the 8th at 5:28 p.m. EST resulting in a New Moon. The pair will set together. Each day after, the Moon will rise increasingly later than the Sun as she heads east through the zodiac band of the Ecliptic much faster than the Sun. Watch the western horizon at sunset over the next few days. It will look like the Moon climbs higher out of the western sky each night while she waxes in light, moving away from the Sun. The First Quarter Moon occurs on the 15th at 7:16 p.m. EST when the Moon perfects waxing square to the Sun. Her right or western side will be illuminated. This time Moonrise occurs in the day around 11:30 a.m. LT and Moonset occurs around 1:45 a.m. LT in the middle of the night. The Moon reaches apogee, her farthest distance from Earth of 252, 156 miles on the 19th at 11:59 p.m. EST. She opposes the Sun on the 23rd at 11:54 p.m. EST resulting in a Full Moon. This time keep your eye on the eastern horizon at sunset and watch for the rising Moon. Notice how the Moon rises roughly one hour later each night as she wanes in light, moving east toward the Sun again.

Planet Data: Stations & Conjunctions
Jupiter stations retrograde on the 1st at 9:26 p.m. EST. The Sun conjuncts Neptune on the 3rd at 2:30 p.m. EST. Mercury conjuncts Neptune on the 8th at 5:10 a.m. EST. On the 14th Mercury reaches superior conjunction with the Sun at 5:50 a.m. EST. The two inner planets can never travel far enough from the Sun to form oppositions. However, they make two different kinds of conjunctions: superior and inferior. Superior Conjunction is when the Sun in between Earth and either Mercury or Venus. Inferior conjunctions occur when Mercury or Venus lie between the Sun and Earth. The inferior conjunction is when retrogradation of the inner planet occurs. All planets only appear to go backwards when they are nearest Earth. Later on Valentineís Day at 7:48 p.m. EST, Venus conjuncts Neptune. On the 20th, Mercury conjuncts Uranus at 12:43 a.m. EST. The Sun conjuncts Uranus on the 25th at 1:33 a.m. EST.

Guide to planet watching in North America
Mercury rises about 15 minutes before the Sun on the 1st. You will be lucky to catch a glimpse of him very low along the eastern horizon this morning. Mercury then moves east behind the Sun where he will reemerge as an evening planet on the 25th. Watch as he climbs a bit higher out of the sunset, becoming visible a bit longer each night as he travels east faster than the Sun. Mercury sets almost due West about 45 minutes after the Sun on the 25th and 65 minutes after on the 28th. Mercury is located along the edge of the dimmer stars of the constellation Pisces just coming out of the boundary of Aquarius. To the left or toward the SW, Cetus is setting. To the right or toward the NW, Pegasus is setting. A sky map of Mercury on the evening of the 28th is available in the OCA Main Public Library.

Venus rises about 45 minutes before the Sun on the 1st. She rises only 15 minutes before the Sun on the 19th. During this time, Venus will move through the constellation Capricornus. This half hour difference makes sense mathematically considering the horizon moves roughly 15 degrees every hour. Venus moves 7 degrees more than the Sun this month, so as she heads East toward the Sun, her viewing time will diminish by about 30 minutes. After the 19th, you will not be able to view Venus until May when she returns from her journey behind the Sun to reappear as an evening planet.

Mars rises around 5:00 a.m. LT on the 1st between the boundaries of Scorpius and Sagittarius near the foot of Ophiuchus. By monthís end, he will rise around 4:30 a.m. LT. Marsí magnitude is only slightly less than that of his stellar rival Antares, the heart of the Scorpion. Both appear to be red stars so be sure you donít confuse the two. Mars is to the left or east of Antares, clearly outside the boundary of Scorpius and Mars will not twinkle. Antares will blink because stars shine by their own light as a result of nuclear fusion at their cores. Planets shine due to the Sunís reflection off their atmosphere and therefore do not twinkle. Also an excellent way to tell if you are locating Antares or Mars is to see which one is moving. Antares is a fixed star, so its position will stay the same against the night backdrop of the stars. Mars will move east, along the fixed stars of the constellation Sagittarius, moving through the top of The Archerís bow and passing his shoulder.

Jupiter rises around 11:10 p.m. LT on the 1st among the stars of the constellation Virgo. By monthís end, he will rise around 9:15 p.m., still among the constellation Virgo. Due to Jupiterís retrograde station this month, we will not detect any movement from this planet. He will appear to stay within about 1 degree of where he started. The bright star you will see below Jupiter, and rising roughly a half hour later, is Spica. Jupiter is much brighter, outshining Virgoís alpha star by about 3 magnitudes. Jupiter sets in the day, so he is visible until dawn encroaches to blot him from view. A sky map of the western sky on 15th around 5:00 a.m. depicting the position of Jupiter and Saturn is located in the OCA Main Public Library.

Saturn is traveling retrograde through the constellation Gemini and moves almost 2.5 degrees backwards. This slight westward movement from one night to the next may be hard to detect unless you skip watching him until half way through the month and then donít look again until the end. Saturn rises in the daytime, so he will be visible in the eastern sky as sunset darkens the skies. What you will notice with Saturn is that he will be higher in the eastern sky each night at sunset. Saturn is about a magnitude brighter than Pollux and Castor, the Twinsí heads. As he rises he will be below and to the right of those two fixed stars. After he culminates and begins his descent into the western horizon, he will be below and to the left of them. Saturn sets around 6:20 a.m. LT on the 1st. By monthís end he will set around 4:35 a.m. LT.

The Moon Dances with the Planets
On the morning of the 4th, notice the Moon between Antares and Mars. By the morning of the 5th, she will have passed Mars in her eastern trek across the ecliptic. On the morning of the 6th, she lies between Mars and Venus. A sky map of the morning of the 6th is available in the OCA Main Public Library. Look for the Moon to rise with Venus just before sunrise on the 7th. The New Moon is the next evening, so her balsamic sliver will be very thin. Look for Saturn to pop into view below the Moon at sunset on the evening of the 19th. By the 20th, she will have passed Saturn as she hurries east. The Moon will rise just before Jupiter on the 26th. Jupiter will rise first on the 27th.

Guide to planet watching in Australia
Mercury rises about a half hour before the Sun, so you should be able to catch a glimpse of him low along the eastern horizon this morning and possibly through the 4th before he passes behind the Sun. Mercury will not become visible as an evening planet until next month. However, you do get to see him for a longer period of time in the morning than those in North America.

Venus rises almost an hour before the Sun on the morning of the 1st near the foot of Capricornus, coming from the Sagittarius. Watch this month as she moves east through the entire constellation of Capricornus and makes her way into Aquarius. She is gaining on the Sun in her quicker eastern trek through the zodiac band of the Ecliptic and her viewing time before sunrise will diminish as the month progresses. You will likely be able to view Venus the entire month if you are far enough away from city lights. By the morning of the 28th, Venus will rise about 15 minutes before the Sun among the fixed stars of the constellation Aquarius. Next month Venus will make her journey behind the Sun, not to be seen again until May when she returns as an evening planet.

Mars rises around 2:00 a.m. LT on the 1st near the foot of Ophiuchus between the constellations Scorpius and Sagittarius. He will be below and slightly to the left of his stellar rival, Antares, the heart of the Scorpion. Both will appear red, so do not confuse the two. Marsí eastward movement away from twinkling Antares, through the constellation Sagittarius will set the wandering planet apart from the fixed star. Watch as Mars moves through the upper region of The Archerís bow and passes his shoulder by monthís end. On the 28th Mars rises around 1:35 a.m. LT.

Jupiter rises around 10:30 p.m. LT on the 1st in the constellation Virgo. Spica, Virgoís alpha star will rise with him to the right. After Jupiter culminates and Virgo begins her descent into the western horizon, you will find Jupiter to be lower in the sky than Spica. Jupiterís retrograde station this month leaves him rather stationary in the night sky. Moving only a degree backwards, it is not likely you will detect his westward movement against the backdrop of the fixed stars. By monthís end, Jupiter will rise around 8:45 p.m. LT with Spica still to the right. It will be daylight before Jupiter sets, so you can watch his journey across the night sky all month. Observers in Southern Australia have a special treat this month as the Moon occults Jupiter on the 27th. A sky map of the Moon passing in front of Jupiter on the night of the 27th is available in the OCA Main Public Library. Saturn is in this map as well. OCA Main Public Library.

Saturn rises before the Sun sets and will be visible rather low in the northeast as the evening sky darkens this month. As the month progresses, Saturn will be higher in the northwest sky at sunset. Watch for two stars to pop into view below Saturn. Those will be Pollux and Castor, the heads of the Gemini Twins. Pollux is brighter and will come into view first. Saturn will be visible on the 1st until around 3:45 a.m. LT when he sets in the west. On the 28th he will set around 2:00 a.m. LT.

The Moon Dances with the Planets
The Moon will lie between Antares and Mars on the morning of the 5th. She dances just to the right of Mars on the morning of the 6th. On the 7th she will be midway between Mars and Venus. The Moon dances just above Venus on the morning of the 8th. A sky map of this morning is available in the OCA Main Public Library. OCA Main Public Library. Looking NNE as the sky darkens on the evening of the 20th, notice the Moon hanging below Saturn but above Pollux and Castor. On the 27th, you will be able to view the occultation of Jupiter by the Moon if you are in the very southern parts of Australia.