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The Big Dipper, the Pointers and Polaris
Want to find Polaris, the North Star? The entire northern sky turns around it. If you can find the Big Dipper, you can always find Polaris.
January 1, 2026
Planisphere: Your friend to find stars and constellations
A planisphere is an easy-to-use tool that can help you learn the night sky. Align the date and time to see what constellations and stars are overhead.
January 1, 2026
First quarter moon appears half-illuminated
The first quarter moon is halfway between new and full moon. Half of the moon is illuminated and it's a quarter of the way through it's orbit around the Earth.
January 1, 2026
What is the zodiac? Why is it important in astronomy?
Maybe you associate the word zodiac with astrology. But it has an honored place in astronomy, too. It's defined by the path of the sun across our sky.
January 1, 2026
How often do 7 eclipses occur in 365 days?
It's rare to have 7 eclipses in a calendar year. It's less rare to have 7 eclipses in 365 days. There are 7 eclipses in 365 days 29 times in the 21st century!
January 1, 2026
What is a waxing gibbous moon?
A waxing gibbous moon is in the sky before it's dark and lights up the early evening. It's more than half lighted, but not quite full. It sets after midnight.
January 1, 2026
What is a waning gibbous moon?
The waning gibbous moon falls between the full and last quarter moon. Watch for it to rise late at night. Or see it in the west in the morning.
January 1, 2026
Sky measurements: Degrees, arcminutes and arcseconds
What are sky measurements - or distances - in the night sky? Here's what it means for objects to be several degrees (or arcminutes or arcseconds) apart.
January 1, 2026
What is a new moon? It rises and sets with the sun
The new moon generally can't be seen, except during a solar eclipse. The moon crosses the sky with the sun during the day, and its shadow side faces Earth.
January 1, 2026
What’s the youngest moon you can see with your eye alone?
It has long been a sport for skywatchers to spot the youngest moon after sunset, with the eye alone. What does it take to see a very young crescent moon?
January 1, 2026
