Skywatch Line for Wednesday and Thursday, March 6 and 7, 2024, written by Alan French
This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, March 6 and 7, 2024, written by Alan French.
The Sun rises at 6:22 A.M. on Wednesday and sets at 5:52 P.M. On Thursday it rises at 6:20 and sets at 5:53. This Thursday has 20 ¼ minutes more daylight than last Thursday.
The Moon reached last quarter last Sunday and is now moving toward new. The Moon rises at 4:25 Wednesday morning and a 21% illuminated, waning crescent is visible 7 ½ degrees above the southeastern horizon at 5:30 A.M. At 5:30 Thursday morning the Moon will a little farther east, only 2 ½ degrees high, and 12 ½% in sunlight. The Moon will reach new this coming Sunday.
After the upcoming new Moon, our next new Moon, on Monday, April 8, will feature a solar eclipse, which will be total along a path in the U.S. stretching from Austin, Texas, through Buffalo, and then up through Plattsburgh. To experience the uniqueness of a total eclipse, residents of the Capital Distinct region will have to travel west or north. It will be a partial eclipse here, although, at maximum eclipse, most of the Sun will be covered by the Moon. To safely view the partially eclipsed Sun, you need ISO certified solar eclipse glasses or filters. It is NEVER SAFE to view the Sun by eye. Damage to your eye’s retina is painless and permanent. (Telescopes also require special filters, designed specifically for safe, solar viewing.)
For detailed information on safe solar viewing, visit the link in the first comment below.
Last week we talked about the varying apparent size of the full Moon. As we noted, the apparent size of the full Moon can vary from 29 ½ to 33 arcminutes. While we tend to pay attention to the aesthetic full Moon, and have come to note the “Super Moons,” larger full Moons than normal, its size varies the same way at any phase. The apparent size of the new Moon plays a role in solar eclipses.
Some of you may recall that residents of the Capital District were treated to an annular solar eclipse on a lovely, sunny day on May 10, 1994. The new Moon passed in front of the Sun from here, but appeared too small to completely cover the Sun. During the eclipse the Moon was less than a day from its farthest point form Earth. The new Moon appeared only 29.9 arcminutes in diameter, too small to completely block the 31.7 arcminute diameter Sun. At maximum eclipse, a bright ring of sunlight, or annulus, surrounded the silhouette of the new Moon. The Sun was too bright, and the beautiful solar corona, seen during a total eclipse, never appeared.
The April 8 eclipse will be longest near Nazas, Mexico, where it will last 4 minutes, 38 seconds. From there, the Moon will appear 33.9 arcminutes in diameter and the Sun will be 31.9 arcminutes across. When the path of totality crosses Plattsburgh its duration will be 3 minute 23 seconds. The longest recent eclipse was experienced near the west coast of Mexico on July 11, 1991, when totality lasted 6 minutes 53 seconds. There will not be a longer eclipse until June 13, 2132.