Feb. 1: Mercury is at greatest easterly elongation, a position at which, seen from earth, it is at its greatest distance to the left (east) of the sun. This places the planet where it remains in the western sky each evening as the sun goes down, in the best position for it to be seen as an evening star. Whether or not the planet will be easily visible in the evening sky depends on how far to the sun's left it is located when elongation is greatest (the distance can vary considerably depending on where Mercury and earth are located in their elliptical orbits) and on the time of year, which determines the direction in which the elongation is measured from the sun, relative to the horizon in the earth's sky.At this elongation, conditions are fair; Mercury is by no means at the maximum elongation distance it reaches, but the direction from the sun is good. This is not what we would call a "favorable" elongation; it is also better than those one would call "unfavorable." You might be able to see the planet low in the west about an hour after sundown, if the horizon is exceptionally clear.
Feb. 3: The waning crescent moon passes Venus today, but both are much too close to the sun to be seen in the morning sky. They simply rise too late.
Feb. 4: The first of this year's three eclipses (neglecting the penumbral lunar eclipse of January 20) occurs today in the South Pacific Ocean. It is a solar eclipse, annular along a narrow path that skirts past almost every major land mass in the vicinity, partial over a much wider area including part of Australia, Antarctica and western South and Central America (where the eclipse is already underway at sunrise). The path of the annular eclipse, from which the moon covers all of the sun except a thin ring -- or annulus -- around its circumference, does cross over the large island Tasmania, south of Australia. In an annular eclipse, the moon's shadow points directly at earth, but it is too short to reach the surface.
Feb. 5: The early crescent moon passes very close to Mars this evening, close enough to cover the planet (an occultation) over the Southern Hemisphere. But the moon and Mars set shortly after 6:00 p.m. tonight, less than an hour after sunset, and there will be no chance to see them in the twilight sky.
Feb. 7: Mercury is stationary and begins its retrograde (westerly) movement through the stars as it moves in between sun and earth.
Feb. 8: The moon is at perigee, the position in its orbit that is nearest to the earth.
Feb. 10: Though they are much too close to the sun's position for us to see them, it is interesting to note that Mercury and Mars are in conjunction today as Mercury, moving retrograde (westerly) passes the more distant planet from left to right. This is part of another triple conjunction taking place this year, similar to the one involving Jupiter and Saturn. Mercury passed Mars on January 23 going east, then turned around on February 7 and passed it again today going west. Mercury will turn around again on March 1 and pass Mars over more going east in late April. Unlike the triple conjunction of Jupiter and Saturn, however, occuring while the two planets are easily visible in the night sky, the events involving Mercury and Mars occur while they are very near the sun's position and cannot be seen.
Feb. 12-13: The star near the moon tonight, from after sunset until they set at about 2:00 a.m., is Aldebran, in Taurus. The moon occults the star over the northern part of North America at about 5:00 p.m. EST, but it will be seen separating slowly to the star's left (east) after dark.
Ftion, passing between sun and earth. The planet, in passing the sun from left to right, enters the morning sky.
Feb. 18-19: Jupiter passes Saturn again tonight, the second of the three events in the triple conjunction involving the two planets. Both are moving westerly (retrograde), to the right, as you can see by comparing their positions from time to time with that of the bright star Spica, in Virgo, well to their left. Jupiter, brighter of the two and moving faster, catches and passes Saturn.The two planets have been very close for months now and will remain close for months to come. Although Jupiter has now moved past Saturn to its right (west), it will not get very far before it turns around east again to approach and pass Saturn once more going the other way.
Feb. 21-22: Be sure to look for the moon, Jupiter and Saturn tonight! They will rise about 2 1/2 hours after sunset, the moon very bright (only three days past full) and very close above the two planets. Watch during the night and you will easily see the moon separate from them to the left (east).
Feb. 21: Mercury, now a morning star, passes Venus, but they rise too late in the morning to be seen.
Feb. 24: The moon is at apogee, farthest from the earth.