Last eclipse

Natural History, Feb, 1998 by Joe Rao

On either side of the path of totality is the penumbra, a region of semishadow that gradually increases from total darkness to full illumination. Parts of the United States and Canada fall within the penumbra. A partial solar eclipse will be visible in these areas, but its magnitude diminishes with distance to the west and north. At San Juan, Puerto Rico, the magnitude of the eclipse will be 90 percent. It decreases to 50 percent at Miami, 25 percent at Atlanta, 22 percent at New York, 14 percent at Dallas, 5 percent at Chicago, and 2 percent at San Diego. Those north of a line running roughly from Los Angeles to Sault Sainte Marie, Michigan, to Nain, Labrador, will not witness the event. The eclipse will occur in midmorning in the southwestern states and progressively later in the day to the east.

One word of warning: take every precaution for eclipse viewing! Never look at even a tiny bit of the Sun's disk unless you are using a proven filtration device, such as #14 welder's glass or aluminized Mylar plastic, to protect your eyes. You can usually find all the safety tips you need in your local newspaper.

The Sky in February

Mercury is invisible this month as it passes through superior conjunction - beyond the Sun as seen from Earth - on the 22d.

Venus is moving rapidly west and away from the Sun. By the end of the month it stands 25 [degrees] above the southeastern horizon at sunrise. Greatest brilliancy (-4.6 magnitude) is on the 20th. The Moon, en route to eclipsing the Sun on the 26th, will be passing by Venus on the mornings of the 23d and 24th.

Mars, at magnitude 1.2, is low in the southwestern sky at sunset and sets one to two hours later. It is closing in on the Sun, and by months' end will be lost in the glow of twilight.

Jupiter, like Mercury, is invisible much of this month as it arrives at superior conjunction, on the far side of the Sun, on the 23d.

Saturn is the lone evening star this month; the yellowish white planet shines at 0.7 magnitude in the western sky for three to five hours after sunset. It's near the Moon on the 1st.

The Moon is at first quarter phase on the 3d at 5:53 P.M., EAST, and is full on the 11th at 5:22 A.M., EST. The Moon is at last quarter on the 19th at 10:26 A.M., EST, and the new Moon occurs on the 26th at 12:25 P.M., EST.

Joe Rao is a lecturer at the American Museum-Hayden Planetarium. He will speak about the eclipse on February 11. See the "Events" column on page 84 for more details.