A ringless Pluto means smooth sailing for New Horizons

Before scientists visited Pluto, they thought it might have rings. But according to a paper posted in September to the preprint server arXiv.org, a close examination of the dwarf planet revealed no rings or debris. And that's a good thing, writes Lisa Grossman for Science News, because colliding dust-and-debris-filled rings could mean the end of a spacecraft like New Horizons.

Why it matters: If Pluto doesn't have rings or debris, it's possible other Kuiper Belt objects won't have them either. On January 1 2019, New Horizons is set to visit 2014 MU69, a Kuiper Belt object approximately 20 miles long. If the flyby happens safely, New Horizons will continue on to even more distant objects.