I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.
London isn't simply urging you to live boldly—he's articulating something more unsettling: that a brief, incandescent existence might be morally superior to a long, comfortable one. The real provocation lies in his acceptance of the meteor's inevitable burn-out; he's not promising you'll also become permanent, just that the trade-off is worthwhile. Consider the person who leaves a stable career to write, paint, or build something; they're not naïve about the risk of obscurity or failure, yet they choose the brightness anyway. What makes this different from mere carpe diem is that London grants the planet its dignity—it's not sleepy because it's foolish, but because constancy and brilliance rarely occupy the same body.