We live — and stop me if I’m going too fast — on a planet. I mean, sure, duh. But this isn’t the natural state of the Universe; or, at least, it’s not the way things usually are. Most of the Universe is pretty empty — that’s why we call it “space” — and if… Read More »
The Solar System is the name we give to our local cosmic backyard. A better way to think of it is all the stuff held sway by the Sun’s gravity: The Sun itself, planets, moons, asteroids, comets, dust, and very thin gas. If you took a step back — well, a few trillion steps back… Read More »
Y’know, if Shakespeare had been an astronomer, he’d have said that “there is a tide in the affairs of the Universe, and on such a full sea are we now afloat.” He would’ve been right. You might just think of tides as the ocean going in and out every day, but in fact what astronomers… Read More »