Bob Moler's Ephemeris Blog

This is Ephemeris for Tuesday, March 25th. Today the Sun will be up for 12 hours and 26 minutes, setting at 8:02, and it will rise tomorrow at 7:34. The Moon, 3 days past last quarter, will rise at 6:24 tomorrow morning.

The evening sky will stay dark for the rest of the week, so it’s time to look for the zodiacal light in the evening. It is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. It’s a glow whose wide base is in the west that extends upwards and to the left. Right now, the end of astronomical twilight is about 10:05 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around the Sun.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). Times will be different for other locations.

Addendum

Zodiacal light will not be as obvious as it appears in the above photographs, where I got to play with brightness and contrast. It takes a bit of observation back and forth to spot the glow. Once found it will be easier to spot in future attempts. Zodiacal light can also be seen on fall mornings in the east before twilight begins. The glow will lean to the right instead of to the left.