What is a last quarter moon?

The last quarter moon appears a week after full moon and a week before new moon. The moon appears half-lit, like half a pie.

At aphelion: Does the size of sun look smaller?

Earth's farthest point - aphelion - in orbit around the sun is around July 6. The eye can't detect it, but a camera shows the sun appears at its smallest then.

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.

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.

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.

Neptune at opposition on September 26, 2026

Neptune at opposition - when it's 180 degrees from the sun on the sky's dome - comes on September 26, 2026. You'll need optical aid to spot it.

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.

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!

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.

What’s a supermoon? Here are the supermoons in 2026

What's a supermoon? In 2026, we will have three full supermoons and five new supermoons. The first full supermoon is in January.