April 1996

by Steve Stefanik

On Wednesday evening, the 3rd of April, the sun sets in the west at 6:13 p.m. as the full moon rises in the east at 6:08 p.m. EST. They will be all but a few minutes from directly 180 degrees across from one another. However, the earth will be between the two and as a result the moon will already be in the shadow of our planet beginning a total lunar eclipse. If you live where the eastern horizon has no obstructions (such as trees) you may be able to see a sliver of the trailing edge of the moon still illuminated but in all likelihood by the time the moon gets high enough above the horizon it will have all but disappeared being submersed in the darkest portion of the earth’s shadow, the umbra, by 6:30 p.m. so you may have difficulty locating it.

Mid-eclipse will occur at 7:12 p.m. Ordinarily during past lunar eclipses we have seen a somewhat visible burnt orange or a brick red fully eclipsed moon. But, because the moon will be so low on the horizon during this eclipse, we will be looking horizontally through most of the earth’s atmosphere near the surface where the air is the dirtiest from all the dust and pollutants stirred up from the activity of the day. I wouldn’t be surprised if it were dark brown or even black this time, making it all the more difficult to locate it. Also, during past total lunar eclipses, we have had the opportunity to watch it as it passed slowly from the penumbral phase where it gradually darkened into the darkest umbral phase while enabling us to keep an eye on it.

My suggestion then, if you can remember to do it, is to locate where the moon rises on the eastern horizon in the evening on the day before the eclipse (April 2nd) and "mark" it with some landmark on the horizon. It should rise just a little to the left of that spot.

By 8:55 p.m. totality will end and a sliver of the of the lunar surface will once again become illuminated on the left side as the moon again reenters the penumbra reversing the process. By 10:04 p.m. the full moon will be totally visible for the first time.

If for some reason you miss the event, there will be another total lunar eclipse on September 26th of this year.

By now you have probably heard some of the hoopla about the comet discovered by Yuji Hyakutake that is presently visible in the sky or perhaps you have seen it yourself as a naked-eye second magnitude "fuzzy star" near the Big Dipper or saw the full-color picture of it taken by fellow astronomer and New Hampshire Astronomical Society member Joel Harris on the front page of Monday’s March 25 edition of the Manchester Union Leader. This is a previously unknown long-period comet with an orbital period of 18,000 years. The last time it passed by this way no one was around to record its appearance so we got caught by surprise this time! Its traveling so fast that when I wrote the March SkyWatch column it was still below the eastern horizon here and was only visible as a 6th magnitude "blob" from Japan and Australia. Since then it has brightened to 0 absolute magnitude and developed a 35 degree tail covering 1/3 of the sky as it passed within 0.1 A.U. (astronomical unit about 9,000,000 miles) of Earth. Although it has reached its closest point to Earth, it will still be visible for several more weeks as it makes its way through Ursa Minor (the Little Dipper) and Perseus on its way to perihelion where it will get lost in the glare of the sun. The tail may get brighter and longer however, as the solar wind pushes it away. The best may be yet to come!

Time will tell. Keep watching.