As the sun sets Thursday evening the waxing crescent moon appears high in the south, its lower tip pointing to the star Aldebaran a few degrees away. Aldebaran is a red-giant that marks the eye of Taurus the bull. Just to the left of the moon is the Hyades cluster, a V-shaped pattern of stars that make up the face of the bull. Higher above the moon is the Pleiades cluster, marking the bull’s shoulder. Named after the seven daughters of Atlas, six of the mythological sisters are visible to the naked eye. How many can you spot?

The waning crescent moon ends the week low in the southeast before dawn. Sunday marks the new moon, the second in March. But it’s not gone long, reappearing as a thin sliver above the western horizon at sunset on the 31st.     With the moon out of sight much of the night, this week provides one of the best chances to see the zodiacal light, a hazy glow that extends like a cone from the western horizon pointing heavenward also called false dawn. It appears an hour or two after sunset, and you’ll only see it with clear, dark skies.

Perhaps you’ll be at lunch Thursday at 12:57pm. Or maybe you’ll be busy at work or school. At that particular time, however, the sun shines directly above the equator. That morning it rises due east, and that evening it sets directly west. This is the vernal equinox, the first day of spring for the 90 percent of the world’s population living in the Northern Hemisphere. In the Southern Hemisphere, it is the first day of fall. Regardless of where you live, your day will be more or less split equally between daylight and night.

With our return to Daylight Saving Time, I wake greeted by Venus blazing in the southeast. The Morning Star rises around 5:30, and an hour later it is well perched above the horizon, shining brighter than any object other than the moon and sun. As sunrise nears and if the sky is clear, another bright light appears 20 degrees in Venus’s wake, Mercury.

Despite our recent snowy, cold spell, signs of spring are everywhere as the earth awakens from its winter hibernation. Long ago, the Celts of pre-Christian western Europe called this time of year the quickening. To them, all objects of Earth — not just creatures, but trees, stones and the ground itself — were alive, all sharing the same sap of life. Now, deep within the still-bare trees, the sap of life flows, birds build new nests; shoots of the earliest spring flowers pierce the frozen soil. All around us, the earth’s pulse is picking up its pace.

The Globe at Night campaign continues through the end of the month, so you still have a chance to contribute to this stellar effort. “Citizen scientists” — that’s you and me — are asked to study the constellation Orion and upload your sightings to the organization’s web site. Find details at www.globeatnight.org.

With the moon waning through pre-dawn skies, this week marks the year’s second Globe at Night backyard observing drive, which aims to enlist you in charting the night sky. The goal: “to raise public awareness of the impact of light pollution by inviting citizen-scientists to measure their night sky brightness and submit their observations to a website from a computer or smart phone.”

As the sun sets, one of the first constellations to appear is Orion, already high in the southeast, and by 8pm looming in the south. With its geometric, hourglass shape, Orion is one of the easiest constellations to spot and one of the most rewarding to study. The brightest star is blue-white Rigel to the lower right, marking the hunter’s left knee. Opposite to the upper left is the red-giant Betelgeuse, punctuating Orion’s raised right arm.

Winter, spring, summer or fall, there’s always a blockbuster overhead on any clear night.     Mercury still clings to the west-southwest horizon a half-hour or so after sunset at week’s end. It is surprisingly bright, but you may need binoculars to pick it out amidst twilight’s glare. Catch this one while you can, as it’s on its final showing.

If you’re up before the sun, you can’t miss Venus, which rises in the southeast by 6am. A half-hour later, this Morning Star is ablaze a good 30 degrees above the horizon, brighter than anything but the moon and the coming sun. As the horizon brightens, Venus climbs higher, growing dimmer until blinking out of view by 7:30am. Wednesday morning, January 29, look for Venus just four degrees above a thin, waning crescent moon before dawn.