Posts by

Bruce McClure

Meet the Winter Circle, aka the Winter Hexagon

The brightest stars in the Northern Hemisphere's winter sky form the shape of the Winter Circle, or Hexagon, that will help you locate 6 constellations.

Bruce McClure

Kelly Kizer Whitt

January 15, 2026

The Hyades star cluster: The Face of Taurus the Bull

Look for the V-shape Hyades star cluster in Taurus the Bull in the evening sky. It represents the Face of the Bull and it's beautiful in binoculars.

Bruce McClure

January 11, 2026

Full Blue Moon on May 30-31, 2026: What’s a Blue Moon?

There's a full Blue Moon overnight on May 30-31, 2026. A Blue Moon is the 2nd of 2 full moons in a calendar month or the 3rd of 4 full moons in a single season.

Bruce McClure

Deborah Byrd

January 1, 2026

How far is a light-year? Plus, distances in space

How can we comprehend the distances to the stars and other galaxies? Here's a way to understand a light-year in terms miles and kilometers.

Bruce McClure

January 1, 2026

What’s a Blood Moon? All you need to know

By this definition, Blood Moon is a member of a special kind of lunar tetrad : four total lunar eclipses in a row. Now it's used for any total lunar eclipse.

Bruce McClure

Deborah Byrd

January 1, 2026

What is an astronomical unit?

An astronomical unit - or AU - is a measurement that astronomers use to describe distances in the solar system. Find out how long an AU is here.

Bruce McClure

January 1, 2026

Is only 2 full moons during a season possible?

We know it's possible to squeeze 4 full moons into a single season. But can a season have just 2 full moons? Turns out it can, but it is rare.

Bruce McClure

January 1, 2026

What is stellar magnitude?

The brightest stars to the eye are 1st magnitude, and dimmest stars to the eye are 6th magnitude. How does stellar magnitude work in astronomy?

Bruce McClure

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!

Bruce McClure

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?

Bruce McClure

Deborah Byrd

January 1, 2026

Bruce McClure

Bruce McClure served as lead writer for EarthSky's popular Tonight pages from 2004 to 2021, when he opted for a much-deserved retirement. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also wrote and hosted public astronomy programs and planetarium programs in and around his home in upstate New York.