MythBuster: Polaris is the Brightest Star in the Nighttime Sky
Look up on a clear night in the Northern Hemisphere, and you might be tempted to think Polaris—the North Star—is the brightest star shining above. It sits high in the sky, seemingly unmoving while the rest of the stars wheel around it. It's guided sailors, explorers, and even freedom seekers through the ages. Surely, a star so legendary must be the brightest one we see, right?
Not quite.
The Truth: Polaris is Bright, But Not the Brightest
Despite its fame and importance, Polaris doesn't even crack the top ten brightest stars in the sky. In fact, it's only the 48th brightest star visible from Earth. That’s right—there are 47 stars that outshine it, including Sirius, the true brightest star in our night sky.
So, where does Polaris earn its reputation? Not in brilliance, but in reliability.
A Star That Doesn’t Set
Polaris holds a unique position in the sky. It sits almost exactly above Earth’s north rotational axis, near the north celestial pole. Because of this, it appears to stay nearly motionless in the sky as the rest of the northern sky seems to spin around it. While other stars rise and set throughout the night, Polaris remains fixed in place. That’s what makes it so easy to find—and so valuable as a navigational guide.
Face Polaris, and you’re facing due north. Extend your arms: your right points east, your left points west, and behind you is due south. This makes Polaris an essential tool for navigation, especially before the age of GPS. Even under a moonlit sky that dims other stars, Polaris is usually easy to spot.
How to Find It
Even though it’s not the brightest, Polaris is very findable. Just look for the Big Dipper, one of the most recognizable star patterns in the Northern Hemisphere. Find the two stars at the end of its bowl—Dubhe and Merak—and draw a line through them. Extend that line about five times the distance between Dubhe and Merak, and it’ll point you directly to Polaris, which sits at the end of the Little Dipper’s handle.
A Celestial Clock
The Big Dipper appears to circle Polaris every 24 hours, moving counterclockwise like the hour hand of a great sky-clock. No matter the time of night or day of the year, the Dipper’s pointer stars always aim at Polaris, helping people track time and direction with the stars alone.
Interestingly, Polaris hasn’t always been the North Star—and it won’t be forever. Due to a slow wobble in Earth’s axis called precession, the title of “North Star” changes over millennia. Around 5,000 years ago, a star named Thuban held the role. Polaris is simply the current holder, but it's a good one: bright enough to see easily, and well-aligned with true north.
Bottom Line
Polaris is a superstar in navigation, not in brightness. It ranks only 48th in luminosity, but because of its fixed position in the sky, it's been trusted for centuries to show the way. So next time someone tells you Polaris is the brightest star in the sky, you’ll know the truth—and still appreciate just how special this guiding light really is. Have you ever tried finding Polaris using the Big Dipper?
Did you miss our April MythBuster? Read MythBuster: The Sun is Yellow here! Stay tuned for next month’s myth.