10 Space Landmarks We'd Like to Visit

PSO J318.5-22: Rogue Planet
This artist's conception illustrates a Jupiter-like planet alone and floating freely without a parent star. In 2011, astronomers uncovered evidence for 10 such lone worlds, thought to have been "booted," or ejected, from developing solar systems. Image courtesy NASA/JPL-Caltech

If hanging out on Eris and exiting the solar system leaves you feeling rebellious, your next stop should surely be a rogue planet. Many of these nomads came from good solar families but were thrown out when they became too rambunctious. Maybe you can identify [source: Mosher].

Or maybe we're taking this bad boy/bad girl thing too far. Maybe you're of a more scientific bent, or perhaps you're the romantic type. Well try this on for size: A lone planet, circling the galactic center with no sun to light it, warmed only by internal radiation. Research in the past decade has suggested that such planets might far outnumber stars in the sky, a hidden majority of failed suns or rocky worlds wandering the void, occasionally drawn into the orbits of unfamiliar stars or black holes [sources: Mosher; Phillips].

In 2013, a paper announced finding such a free-floating world in our stellar neighborhood. PSO J318.5-22, a gas giant tilting the scales at around six Jupiter masses, floats a mere 80 light-years from Earth. You might want flip on your infrared sensors to find it, though, because it's optically about 100 billion times dimmer than Venus [sources: Boyle; Liu et al.].