You’ve heard the phrase too many times to count: “Once in a blue moon.” But what is a blue moon, exactly? (Hint: The moon doesn’t actually turn blue, unfortunately.) Despite the misleading name, blue ...

Feeling blue? That color isn't as common as you may think. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. When you look up at the blue sky ...

Blue stars are by far the biggest and brightest stars in the galaxy. To the naked eye, the stars in the night sky all look very similar to each other, the main difference between them being that some ...