Breaking space news, the latest updates on rocket launches, skywatching events and more! You are now subscribed Your newsletter sign-up was successful Want to add more newsletters? A world, cold and alone, drifting through the inky blackness between star systems. Sounds pretty desolate, right? We're talking about free-floating planets, those cosmic wanderers that don't bother with orbiting a sun, just cruising solo through the void. Astronomers reckon there could be a whole bunch of these vagabond rogue planets out there, maybe as many as 21 for every star in our Milky Way galaxy. That's a truly staggering number, a cosmic fleet sailing in eternal night. For a long time, we figured these lonely giants were just that: lonely. Definitely not the kind of place you'd pack a swimsuit. But what if they're not so lonely after all? Now, picture a moon, an exomoon if you will, clinging to one of these rogue planets. No star for warmth, just the cold embrace of interstellar space.…