A Show of Planets

Mercury appears as a rather conspicuous evening "star" for the first three weeks of February, shining at magnitude -1 to 0. By February 6, it sets about an hour and fifteen minutes after sunset. On that same evening, you will find it just 2.5 [degrees] to the right of and slightly above a very thin crescent Moon. Mercury's greatest elongation (or maximum angular distance from the Sun) comes on February 14, when the planet is positioned only 18 [degrees] away from the Sun in the twilight sky but will appear almost directly above it as both descend in the west. The Sun keeps a tight rein on Mercury this month because the planet's greatest elongation falls on the day before its perihelion, when it is physically closest to the Sun. This circumstance offers a very favorable opportunity to see Mercury. Later in the month, as its crescent rapidly thins, the planet plunges back into the Sun's glare and quickly fades. It passes between Earth and the Sun (inferior conjunction) on March 1. Mercury has an undeserved reputation for being hard to see: you just have to look in the right place at the right time. In short, this is a good month to join the small number of people who have laid eyes on the innermost planet.

Venus becomes visible as the night nears an end. It is still brilliant (magnitude -4) in the morning sky, although it is not as high or as prominent as it has been in recent months. At the beginning of the month it rises with the first light of dawn 90 minutes or so before the Sun and is still very low in the southeast as dawn grows bright. It sinks lower and lower as the month wears on, and by month's end it is rising only an hour before the Sun. A waning crescent Moon will be about 2 [degrees] above and slightly to the right of Venus on the morning of February 2.

Mars now appears as a moderately bright yellowish-orange star of magnitude + 1.2. It sits low in the southwest sky at dusk and sets at about 8:30 P.M. local time all through the month. The waxing crescent Moon passes about 50 to the left of Mars at dusk on February 8.

Jupiter, in the constellation Aries, is below and to the right of Saturn during the early evening hours. The king of the planets shines brilliantly at magnitude -2.3 and appears nearly a dozen times brighter than Saturn. These two giant planets slowly edge closer together all month: 12[degrees] separate them on the 1st, 10 [degrees] on the 28th. A fat crescent Moon will pass about 5 [degrees] below and to the left of Jupiter during the late evening hours of February 10.

Saturn shines at magnitude +0.3 and is also found in Aries. It remains about 18 [degrees] southwest of the Pleiades and well to the northeast of Jupiter and is visible until about midnight. A telescope will reveal its beautiful ring system, now tilted some 21 [degrees] to our line of sight, with the south face visible. The Moon will lie about 4 [degrees] to the left of and slightly below Saturn late on the evening of February 11.

The Moon is at new phase on February 5 at 8:03 A.M. First quarter occurs on February 12 at 6:21 P.M., full Moon on February 19 at 11:26 A.M., and last quarter on February 26 at 10:53 P.M.

Unless otherwise noted, all times are given in Eastern Standard Time.

Joe Rao is a lecturer at the American Museum-Hayden Planetarium.

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