The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

A very rare treat is about to grace Earth's night skies.

Space photos remind us that, around every corner of our vast universe, something spectacular ... humanity's first landing on a moon in the outer solar system when it touched down on Titan.

These alignments aren't the neat planetary queues you see in diagrams and illustrations of the Solar System. That's not a thing that actually happens in the real Universe, sadly. Yet the planets ...